JP2007293911A - Semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor device that can obtain an input signal with phase shift eliminated even though there is the phase shift between a received clock and the input signal. <P>SOLUTION: In the semiconductor device provided with a clock generation circuit 451 for generating an internal clock on the basis of a received clock, an input buffer circuit 452 for receiving the input signal and an input circuit 458 for synchronizing with the internal clock to obtain and output the input signal, the input circuit is provided with a delay circuit 460 which delays an output of the input buffer circuit and can select a delay amount; an input circuit 462 which takes in the output of the input buffer circuit synchronizing with an internal clock, a phase determination circuit 465 for determining a phase to the internal clock outputted by the input buffer circuit by determining an output signal value of the input circuit, and a delay control circuit 461 for controlling a delay amount of the delay circuit so as to make the output of the input buffer circuit a predetermined phase to the internal clock on the basis of a determination result of the phase determination circuit. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a semiconductor device that takes in an input signal that is valid in synchronization with an external clock in synchronization with an internal clock generated from the external clock, and in particular, adjusts the timing of the internal clock to adjust the ambient temperature and power supply voltage. The present invention relates to a semiconductor device that takes in an input signal at a predetermined timing.

  In a large-scale semiconductor device system such as a computer using a semiconductor device, each part of the system is configured to operate in synchronization with a clock, and a signal such as a data signal or an address signal is input / output to the clock signal. Done synchronously. FIG. 1 is a diagram showing a configuration example of such a semiconductor device system. The system shown in FIG. 1 controls the input / output of data to / from a plurality of memories 12-0, 12-1, and 12-2 by the controller 11, and particularly shows a configuration for writing data to the memory. Yes. As shown in FIG. 1, a clock signal line 13, a control signal bus 14, an address signal bus 15, and a write data bus 16 extending from the controller 11 are arranged in parallel, and the memories 12-0, 12-1, and 12-2 are Arranged along these signal lines and buses, the terminals of the memories 12-0, 12-1, and 12-2 are connected to corresponding wirings. In the figure, the memories 12-0, 12-1, and 12-2 are shown arranged above the signal lines and buses. It is provided to pass between the terminals. Signals are output from the controller 11 to the clock signal line 13, the control signal bus 14, the address signal bus 15, and the write data bus 16, and each memory takes in the clock and generates an internal clock. Based on the generated internal clock, The control signal bus 14, the address signal bus 15, and the write data bus 16 are fetched, and necessary processing is performed to store the data output to the write data bus. Such memories 12-0, 12-1, and 12-2 operate in accordance with an externally supplied clock and are therefore called a synchronous type. A synchronous DRAM (Dynamic Random Access Memory) is called SDRAM, and the present invention is mainly directed to SDRAM. In the following description, SDRAM will be described as an example. However, the present invention is not limited to SDRAM.

  In recent years, as the clock speed of a CPU in a computer system increases or the processing speed of various other electronic circuits increases, it is necessary to increase the speed of an interface portion connecting each semiconductor device. The SDRAM is a semiconductor device for responding to such a demand for high speed, and can access at a very high speed when accessing consecutive addresses. Therefore, it is a data bus signal that changes in a very short cycle, and it is necessary to capture the data bus signal at high speed.

  FIG. 2 is a diagram showing a most basic configuration example of the semiconductor device system as described above. As shown in FIG. 2, this system includes a driving-side semiconductor device 11 that transmits a signal and a receiving-side semiconductor device 12 that receives the signal. The drive-side semiconductor device 11 outputs output signals D0 to Dn in synchronization with the clock signal CLK together with the clock signal CLK, and the reception-side semiconductor device 12 is sent from the drive-side semiconductor device 11 in synchronization with the received clock CLK. The received signals are taken as input signals Q0 to Qn. Since the semiconductor devices constituting the semiconductor device system perform transmission / reception with other semiconductor devices, they can be on the driving side or on the receiving side depending on the operation.

  FIG. 3 is a diagram showing in more detail the signal transmission and reception paths in the driving-side and receiving-side semiconductor devices. As shown in FIG. 3, the driving-side semiconductor device 11 outputs a clock signal CLK (D) from the clock output circuit 21, and the output signals D0, D1,. 0, 22-1,..., 22-n. The receiving-side semiconductor device 12 receives a clock signal CLK and generates an internal clock, and an input circuit 32 that captures input signals Q0, Q1,..., Qn corresponding to the output signals D0, D1,. , 32-n, and a register 33 provided to receive these signals in an internal circuit that processes the outputs of the input circuits 32-0, 32-1, ..., 32-n. And have.

FIG. 4 is a diagram illustrating a conventional example of an input circuit of a receiving-side semiconductor device.
As shown in FIG. 4, in the input circuit 32, an externally input clock CLK is input to the clock current mirror circuit 41, and its output is transmitted from the clock buffer circuit 42 to each part in the semiconductor device as an internal clock. . Similarly, the input signal is input to the current mirror circuit 43 and then input to the latch circuit 45 via the input signal buffer circuit 44. The latch circuit 45 latches the input signal from the input signal buffer circuit 44 in synchronization with the rising edge of the internal clock from the clock buffer circuit 42. As a result, the input signal is taken into the semiconductor device. The input signal latched by the latch circuit 45 is transmitted to each part of the internal circuit. The current mirror circuit is used to accurately receive a signal input from the outside. 4 shows only one input signal and only one input circuit, there are actually a plurality of input signals, and the current mirror circuit 43, the input signal buffer circuit 44, and the latch circuit 45 There are as many input circuits as the number of input signals.

  In the circuit of FIG. 4, the clock input circuit and the other input signal input circuits have equivalent circuit configurations, and the clock and the input from the input to the semiconductor device to the transmission to the latch circuit 45 are input. The signal delay is the same. Therefore, the relationship between the clock input terminal of the semiconductor device and the timing of the clock input to the input terminal and other input signals is maintained in the latch circuit 135.

  FIG. 5 is a diagram illustrating a clock CLK and signals on the bus in the semiconductor device system. The driving-side semiconductor device 11 changes signals output to the control signal bus 14, the address signal bus 15, and the write data bus 16 in synchronization with the rising edge of the clock CLK. In response to this, the receiving-side semiconductor device 12 takes in the output signal from the driving-side semiconductor device 11 as an input signal in synchronization with the rising edge of the clock CLK. Note that in this specification, an example is described in which the output signal changes in synchronization with the falling edge of the clock CLK and is captured as an input signal in synchronization with the rising edge of the clock CLK. In some cases, the input signal changes with a different phase and is taken into the semiconductor device with a shifted phase.

  When the semiconductor device captures an input signal, a period in which the input signal needs to be determined before and after the capture timing is determined. As shown in FIG. 5, a period in which the input signal needs to be determined before the capturing timing is called a setup time tS, and a period in which the input signal needs to be determined after the capturing timing is a hold time tH. It is called.

  FIG. 6 is a diagram showing the clock CLK and signals on the bus in the semiconductor device system of FIG. 2. The clock CLK (D) and the output signals D0 to Dn when output from the drive side are 7 shows the state when these signals are taken in as the clock CLK (R) and the output signals Q0 to Qn on the receiving side. The driving-side semiconductor device 11 changes the output signals D0 to Dn in synchronization with the falling edge of the clock CLK (D). The receiving-side semiconductor device 12 takes in the output signals D0 to Dn as input signals Q0 to Qn in synchronization with the rise of the fetched clock signal.

  5 and 6, the output signal changes in synchronization with the falling edge of the clock CLK and is taken in as an input signal in synchronization with the rising edge of the clock CLK. However, the output signal is shifted from the falling edge or rising edge of the clock CLK. In some cases, the input signal changes depending on the phase and is taken into the semiconductor device. In the following example, in order to simplify the description, the input signal changes in synchronization with the falling edge of the clock CLK, and the input signal is described as being captured in synchronization with the rising edge of the clock CLK. It is not limited to this.

JP-A-7-98617 JP-A-7-84946 Japanese Patent Laid-Open No. 5-75594

  In the semiconductor device system of FIG. 2, the time for which a signal is transmitted from the driving-side semiconductor device 11 to the receiving-side semiconductor device 12 is defined by the length of the signal line and also varies depending on the load of the signal line. Since the length of each signal line and the load cannot be exactly the same, as shown in FIG. 6, even if the output signal is output from the driving side so as to be synchronized with the falling edge of the clock, the receiving side At the time of input to the input terminal of the semiconductor device 12, a phase difference occurs between the signals. In FIG. 6, time tD is required for the clock to be transmitted from the driving side to the receiving side. That is, the received clock CLK (R) is delayed by tD from the clock CLK (D) output from the driving-side semiconductor device 11. Since the output signal D0 output from the driving-side semiconductor device 11 is transmitted with a delay amount smaller than the clock, the input signal Q0 changes earlier than the falling edge of the clock CLK (R). Similarly, the input signal Qn changes with a delay from the falling edge of the clock CLK (R). If Q0 is the most advanced and Qn is the most lagging, a correct signal is not input until Qn changes after Q0 shown in FIG. 6 changes. It is a definite period. For this reason, the period in which the signal is valid is a period obtained by excluding a period in which the signal is uncertain from one cycle of the signal, that is, one cycle of the clock.

  In recent years, as the clock speed of a CPU in a computer system increases or the processing speed of various other electronic circuits increases, it is necessary to increase the speed of an interface portion connecting each semiconductor device. In a high-speed system using such a high-speed semiconductor device, the input confirmation time for each semiconductor device to take in an input signal defines the system speed, thereby reducing the input confirmation time of the semiconductor device. It is demanded.

  In a low-speed system, such an indefinite period of the signal is relatively small compared to the clock cycle, which is not a problem. However, in a high-speed system, the clock cycle becomes very short, which is a serious problem. Therefore, in high-speed systems, measures such as making the length of the clock signal line and other signal lines the same as much as possible are taken, but it is difficult to make the wiring length and load completely the same, and a certain phase difference This is an obstacle to speeding up.

  Further, there is a problem of phase difference in the receiving-side semiconductor device. FIG. 7 is a diagram for explaining the signal determination time required in the receiving-side semiconductor device. In the circuit of FIG. 4, the latch circuit 45 has a setup time tS and a hold time tH that are inevitably required from the relationship of operation, and FIG. As described above, in the circuit of FIG. 4, the clock input circuit and the other input signal input circuits have equivalent circuit configurations, and are input to the semiconductor device and then transmitted to the latch circuit 45. The delay amount of the clock and the input signal is made the same. However, in practice, it is impossible to make the circuit exactly the same in terms of circuit design, so that the delay amount is as similar as possible, but it must be a somewhat different circuit or wiring. Therefore, considering the variation in the manufacturing process, the temperature dependence of the delay amount, and the power supply voltage dependence, even if the clock input circuit and other input signal input circuits are equivalent as shown in FIG. A difference occurs in the delay amount. Due to this difference in delay amount, the input confirmation time required from the circuit operation varies to some extent with respect to the rising edge of the clock CLK under conditions 1 and 2 as shown in FIG. Therefore, it is necessary that the input confirmation time in FIG. 7 falls within the signal valid time in FIG. 6. If this condition is not satisfied, normal input signals cannot be captured. Conventionally, the input confirmation time, that is, the setup time tS and the hold time tH are defined in consideration of the variation in the input confirmation time required from the circuit operation.

  In recent years, as the clock speed of a CPU in a computer system increases or the processing speed of various other electronic circuits increases, it is necessary to increase the speed of an interface portion connecting each semiconductor device. In a high-speed system using such a high-speed semiconductor device, the input confirmation time for each semiconductor device to take in an input signal defines the system speed, thereby reducing the input confirmation time of the semiconductor device. It is demanded.

  The present invention is for responding to such a request. Even if the clock and the signal are out of phase on the receiving side, the present invention can be used between the clock input circuit and another signal input circuit within the semiconductor device on the receiving side. It is an object of the present invention to increase the speed of a system even when a phase difference occurs, and to realize a semiconductor device for configuring such a system.

FIG. 8 is a first principle configuration diagram of the present invention.
As shown in FIG. 8, in the semiconductor device system of the present invention, in order to achieve the above object, input circuits 53-0, 53-1,. Input timing adjustment circuits 54-0, 54-1,..., 54-n for adjusting the phase of the clock supplied to the input circuit are provided so as to capture in the above-described state. In FIG. 8, reference numeral 51 denotes a clock input circuit, and 55 denotes an internal circuit to which an input signal and a clock taken in by input circuits 53-0, 53-1,.

  That is, the semiconductor device system of the present invention is composed of a plurality of semiconductor devices that operate in synchronization with a clock. When a signal is transmitted between the semiconductor devices, the driving-side semiconductor device outputs a clock and is synchronized with the clock. In the semiconductor device system that receives the output signal output from the drive-side semiconductor device as an input signal in synchronization with the received clock, the reception-side semiconductor device 12 receives the input signal. Input circuit 53-0, 53-1,..., 53-n, and input timing adjustment for adjusting the phase of the clock supplied to the input circuit so that the input circuit captures the input signal in a valid and stable state. Circuits 54-0, 54-1,..., 54-n are provided.

As shown in the figure, it is desirable to provide an input timing adjustment circuit for each input circuit. However, when the skew between the input signals is smaller than the skew between the input signal group and the clock, it is possible to provide an input timing adjustment circuit in common for a plurality of input circuits.
In the semiconductor device system of the present invention, even if there is a skew between the clock and the input signal, the adjustment is made so that the optimum timing is obtained, so that the skew is substantially zero, and the input signal is made effective in the input circuit. Can extend the period.

  The input timing adjustment circuit delays an internal clock generated based on the received clock and outputs it as an input timing clock, and captures the input signal in synchronization with the input timing clock and a delay circuit capable of selecting a delay amount Based on the determination result of the signal input circuit, the input timing clock and the phase of the input signal, and the phase comparison circuit, the delay circuit is configured so that the input timing clock has a predetermined phase with respect to the input signal. The feedback circuit includes a delay control circuit that changes the delay amount.

  When the input timing adjustment circuit is configured with such a feedback circuit, a certain amount of time is required until the control value of the feedback circuit converges. When such a semiconductor device system is started up, a predetermined time adjustment is always required. It is necessary to do the mode. In this adjustment mode, a signal suitable for feedback of the input timing adjustment circuit can be input. Then, it is conceivable whether the feedback control is continued as it is after the adjustment mode is finished or the control value at the time when the adjustment mode is finished is stored and maintained. When the feedback control is continued even after the adjustment mode is finished, it is possible to respond even if there is a phase change after the adjustment mode is finished. It is necessary to be able to perform feedback control with such a normal operation signal. In addition, when storing and maintaining the control value at the end of the adjustment mode, the configuration is simpler than when the feedback control is continued even after the adjustment mode is finished. I can not cope. Therefore, it is desirable to periodically provide an adjustment mode.

  FIG. 9 is a diagram for explaining the principle of phase comparison in capturing an input signal. When comparing the phases of two signals, it is common to compare the context at the changing edges of the two signals to compare whether one is ahead or behind the other. However, in the case of the input circuit, as shown in the figure, the input timing clock DCLK is a signal that changes in a stable state, and the input signal is stabilized before the setup time tS when the input timing clock rises. It is required to be stable for the hold time tH from the rise of. Therefore, it can be said that it is desirable that the input signal change before tP × tS / (tS + tH) of the rising edge of the input timing clock when one clock cycle is tP. The phase cannot be compared at such a change edge of the input signal and the input timing clock DCLK. Therefore, the input timing clock is shifted by a predetermined phase to generate a shift clock SCLK that changes in the same phase as the input signal, and the phase of this shift clock and the input signal is compared, or the input signal is shifted by a predetermined phase and input It is necessary to compare the phase of the shifted input signal shifted from the timing clock. When the shift clock SCLK or the shifted input signal is generated on the receiving side, the input signal can be taken in by the input timing clock DCLK while comparing the phases, and the feedback control is continued as it is after the adjustment mode is finished. It is possible. However, when a signal having a predetermined phase shift is generated on the driving side, a signal different from the normal operation having such a predetermined phase shift needs to be transmitted to the receiving side, and such a signal cannot be transmitted in the normal mode. Therefore, it is possible to generate a signal having a predetermined phase shift on the driving side only when feedback control is not performed after the adjustment mode is completed. When generating an input signal shifted by a predetermined phase on the receiving side, it is necessary to use the input signal received by the current mirror circuit and the buffer circuit as they are for comparison without latching the input signal. Because of the sluggishness, a good comparison cannot be made. Therefore, it is desirable to generate a shift clock when generating a signal having a predetermined phase shift on the receiving side. It is also possible to generate a shift clock on the drive side and transmit this shift clock in the adjustment mode, but the clock is the reference for the synchronous operation, and it is preferable that the clock phase is different even in the adjustment mode. Therefore, when a signal having a predetermined phase shift is generated and transmitted on the driving side, it is desirable to output in synchronization with the shift clock in the adjustment mode and to output in synchronization with the clock in normal operation.

  When performing phase comparison, it is conceivable to compare the phase of the input signal before latching with the input timing signal or the shift clock, but the problem is that it is difficult to make a good phase comparison because the input signal is blurred as described above. There is. Therefore, in the present invention, when an input signal that changes to one side is latched by a timing signal near the change edge, the phase is adjusted by utilizing the fact that the latched value differs depending on whether the phase is advanced or delayed. Make a comparison.

  When there is a reception timing adjustment mode, a signal input to the signal input circuit can be a signal that changes at a predetermined cycle, for example, a signal that changes every clock cycle. Therefore, the input signal changes from “low” to “high” by determining the signal value of a half cycle before a predetermined time before the timing of capturing the signal value to be determined, for example, if the signal changes every cycle. Or whether it changes from “high” to “low”. On the other hand, when the determination is made in the normal mode, the signal taken into the signal input circuit is a normal signal, and it is not known how it changes. In this case, it is possible to determine whether the input signal has changed or which one has changed by determining the signal value before and after the timing of taking in the signal value to be determined.

Next, the basic configuration of the present invention based on the above description will be described. First, in the adjustment mode, a configuration in the case where an output signal having a predetermined phase shift from the driving side as compared with that in the normal operation is output will be described.
FIG. 10 is a diagram showing a basic configuration of the semiconductor device system according to the first aspect of the present invention. The drive-side semiconductor device of this system generates a clock and a shift clock in which the clock is shifted by a predetermined phase, selectively outputs a clock generation circuit, and an output signal in synchronization with the clock or shift clock output from the clock generation circuit Signal output circuits 88-0, 88-1,..., 88-n, and a receiving mode for outputting an output signal in synchronization with a shift clock. The timing adjustment mode can be selected. 10, the clock generation circuit outputs a clock source 81 for generating a basic clock, a shift clock generation circuit 82, and output from the shift clock generation circuit 82 to output circuits 88-0, 88-1,..., 88-n. And a switch 87 for selecting a clock between a basic clock and a shift clock. A dummy output generation circuit 84 is provided to output a signal suitable for adjustment of the input timing adjustment circuit that is output in the adjustment mode, and further, an output from the internal circuit 83 and an output from the dummy output generation circuit 84 are selected. The switch 85 is provided. With such a configuration, an output signal that changes at the rising edge of the clock can be output in the adjustment mode, and an output signal that changes by a predetermined phase shift from the rising edge of the clock can be output in the normal mode.

  The shift clock generating circuit 82 has the same amount of delay in each stage and the delay amount can be selected. Based on the comparison result of the clock phase comparison circuit, which compares the phase of the basic clock with the output of the final stage of the multi-stage shift delay circuit, the phase of the final clock and the basic clock match. A delay control circuit for controlling the delay amount of the plurality of shift delay circuits.

  On the receiving side of the semiconductor device system of the first aspect, in the adjustment mode, the timing of taking in the input signal is adjusted by comparing the phase of the received clock with the received input signal, and when the adjustment mode ends and the normal mode is entered. The control value at the end of the adjustment mode is stored, and thereafter the value is retained. The input signal sent from the drive side in the adjustment mode is a signal that changes at the rising edge of the clock and can be compared as it is, and the value captured by the latch of the input circuit can be used for the determination.

  FIG. 11 is a diagram showing a basic configuration on the receiving side of the semiconductor device system according to the first aspect. As shown in the figure, the phase comparison circuit 70 includes a change information detection circuit 68 and a phase determination circuit 69. The phase determination circuit 69 changes the value latched by the input latch 62 and the input signal detected by the change information detection circuit 68. If it has changed, the phase is compared based on the detection result of the change edge in which direction. In particular, when the input signal sent from the drive side in the adjustment mode is a signal that changes in one cycle of the clock, the change information detection circuit 68 does not need to detect whether the input signal has changed, but simply in which direction What is necessary is just to be able to detect whether it is a change edge.

  FIG. 12 is a diagram illustrating an example of the clock CLK and the output signal output from the drive side in the reception timing adjustment mode (calibration mode) and the normal mode in the semiconductor device system of the first aspect. An example in which the output signal changes in one cycle of the clock is shown. As shown, the clock CLK is the same signal that is continuous in the calibration mode and the normal mode. The output signal is a signal that changes at each rising edge of the clock in the calibration mode, and when it changes in the normal mode, it changes at the falling edge of the clock, but it does not always change.

Next, a configuration in which feedback control of the input timing adjustment circuit can be performed even after the adjustment mode is finished will be described. In this case, the driving-side semiconductor device may have a conventional configuration.
FIG. 13 is a diagram showing a basic configuration of a receiving-side semiconductor device according to the second aspect of the present invention. As shown in the figure, in this semiconductor device, an external clock ECLK is input, a clock generation circuit 51 that generates an internal clock CLK, an input circuit 53 having an input buffer 61 and an input latch 62, and an input circuit that validates an input signal. And an input timing adjustment circuit 54 that adjusts the phase of the internal clock CLK supplied to the input latch 62 so as to capture in a stable state. The input timing adjustment circuit 54 delays the received internal clock CLK and inputs it. A delay circuit 64 that is output as the timing clock DCLK and the delay amount is selectable, a phase comparison circuit 66 that determines the phase of the input timing clock and the input signal, and an input timing clock that is input based on the comparison result of the phase comparison circuit Change the delay amount of the delay circuit so that it has a predetermined phase with respect to the signal. A delay control circuit 65 that shifts the input timing clock by a predetermined phase and generates a shift clock that changes in the same phase as the input signal. The phase comparison circuit 66 is synchronized with the shift clock. A dummy latch 67 that latches the input signal, a change information detection circuit 68 that detects whether the input signal has changed and the direction of the change, and a phase determined based on the value latched by the dummy latch 67 and the detection result of the change information detection circuit 68 And a phase determination circuit 69.

The shift clock is a signal that is shifted by a predetermined phase from the input timing signal. When the phase of the input timing signal is changed and changed, the shift clock needs to be changed accordingly. Therefore, in the second aspect, the shift clock is generated from the input timing signal output from the delay circuit of the input timing adjustment circuit. The shift clock generation circuit 70 can use the same configuration as the shift clock generation circuit 82 of FIG.
On the other hand, in a clock synchronous semiconductor device, a clock having a phase opposite to that of the internal clock is often used inside the device, and an internal clock that is accurately 180 ° out of phase is often generated. Therefore, when the input signal changes at a phase shifted by 180 ° from the rising edge of the clock, that is, when the input signal changes at the falling edge of the clock, this opposite phase clock can be used as the shift clock. FIG. 14 is a diagram showing a basic configuration of a receiving-side semiconductor device according to the third aspect of the present invention applicable to such a case. As shown in the figure, there is provided a shift clock generation circuit 71 that generates a reverse phase clock / CLK that is exactly 180 ° out of phase with the internal clock CLK, and the delay circuits respectively delay CLK and / CLK by the same delay amount 2. It differs from the second embodiment in that it is composed of two delay circuits-1 and delay circuit-2.

  In the second and third aspects described above, a shift clock in which the input timing signal is shifted by a predetermined phase is generated on the receiving side, the input signal is a signal during normal operation, and feedback control can be performed even during normal operation. . The semiconductor devices according to the second and third aspects can also be applied to the case where the control value at the end is maintained after the end of the adjustment mode, in which case the drive side is suitable for the adjustment of the input timing adjustment circuit. It is desirable to output the correct signal.

  Furthermore, at higher speeds, when the value of the input signal changes every clock cycle, the input signal changes to the next value before changing sufficiently to one value, but when the same value continues Since it has changed sufficiently to one value, the waveform that changes to the next value is different and a phase difference occurs. Therefore, when adjusting the input timing, it is necessary to consider the state before the input signal. Therefore, the receiving side of the semiconductor device system of the present invention includes a minimum cycle change detection circuit that detects that the input signal has continuously changed in the immediately preceding two clock cycles, and the delay control circuit includes the input signal that has been input immediately before the input signal. Only when the clock cycle changes continuously, feedback control is performed to change the delay amount of the delay circuit, and at other times, feedback control is not performed. Such control means that the input signal value is adjusted so that the optimum timing is reached every clock cycle. Therefore, when the input signal value is continuous, the input timing signal is accordingly increased. It is desirable to correct Therefore, the receiving side of the semiconductor device system of the present invention detects a timing correction circuit that selects whether or not to delay the capture timing in the signal input circuit by a predetermined amount, and that the input signal has changed in the immediately preceding clock cycle. When the input signal does not change in the immediately preceding clock cycle, the timing correction circuit delays the capture timing in the signal input circuit by a predetermined amount. As a result, the input signal is fetched at an appropriate timing whether the value of the input signal changes every clock cycle or continuously.

  In the configuration of the present invention of FIG. 8, input timing adjustment circuits 54-0, 54-1,..., 54-n are provided for the input circuits 53-0, 53-1,. Therefore, each input circuit can capture an input signal at an optimal timing. However, the outputs of the input circuits 53-0, 53-1,..., 53-n have a phase shift and are not synchronized. Since the operation in the internal circuit 55 is also performed in synchronization with the clock, such a phase shift is not preferable, and the signals input to the internal circuit are preferably synchronized. Therefore, the receiving side in the semiconductor device system of the present invention further includes an inter-signal timing adjustment circuit that detects a phase difference between output signals of the input circuits and adjusts the phase to be the same.

  The inter-signal timing adjustment circuit detects, for example, a period in which outputs of a plurality of input circuits are all signals in the same cycle, and outputs a common effective signal during this period, and a common effective signal It is configured to include a plurality of latch circuits that respectively latch the outputs of the plurality of input circuits during the period, or the signal delay circuit that delays the outputs of the plurality of input circuits and the slowest of the outputs of the plurality of input circuits A delay control register that detects the signal and controls the delay amount of the signal delay circuit so as to match the latest signal is provided. In order to perform such adjustment, it is necessary that all the input signals change in the same pattern, and it is necessary to provide an adjustment mode. The phase difference of the output of each input circuit can also be detected by the control value of the input timing adjustment circuit provided in each input circuit. Therefore, the inter-signal timing adjustment circuit may detect the phase difference between the output signals of the signal input circuits based on the control value of the delay control circuit.

Examples of the present invention will be described below. The first embodiment corresponds to the semiconductor device system of the first aspect shown in FIG.
FIG. 15 is a diagram showing the configuration of the clock generation circuit and the signal output circuit of the driving-side semiconductor device in the semiconductor device system according to the first embodiment of the present invention. In the first embodiment, as shown in FIG. 12, a normal mode and a reception timing adjustment mode are provided and can be switched. When starting up the system, first the timing is adjusted to the reception timing adjustment mode, and then the normal mode is entered. Further, if necessary, the normal mode may be interrupted to shift to the reception timing adjustment mode, the timing adjustment may be performed, and then the normal mode may be restored.

  As shown in FIG. 15, the drive-side semiconductor device of the first embodiment includes a clock source 81 that generates a clock CLK and supplies it to each part of the device, and a basic clock that is the basis of output timing from the input clock CLK. A shift clock generation circuit 82 that generates a ½ shift clock that is shifted by a half cycle and outputs one of them, and a clock that adjusts the delay amount of the clock output from the shift clock generation circuit 82 and outputs an output signal to the outside Delay adjusting circuit 83 for adjusting and outputting the output timing clock so as to synchronize with the output, clock distribution circuit 87 for equidistant wiring for distributing the output timing clock to the output circuit, and output timing clock from clock distribution circuit 87 Output circuits 88-1 to 88-n for outputting signals output from the output signal generation circuit 90 in synchronization with , Output terminals 89-1 to 89-n connected to the output circuits 88-1 to 88-n, an output signal generation circuit 90 having a dummy signal generation circuit 91, and an output from the input output circuit 88-0. A dummy current mirror circuit 62 that receives the signal and a dummy buffer circuit 93 that receives the output of the dummy current mirror circuit 92 and outputs the output to the delay adjustment circuit 83 are included. The delay adjustment circuit 83 includes a delay circuit 84 that can adjust the delay amount, a phase comparison circuit 85, and a delay control circuit 86. The delay adjustment circuit 83 receives an output signal input via the dummy current mirror circuit 92 and the dummy buffer circuit 93. The phase comparison circuit 85 compares the phase of the output timing clock output from the shift clock phase shift circuit 82, and the delay control circuit 86 adjusts the delay amount of the delay circuit 84 based on the comparison result, and the output signal and the output timing clock. Are controlled so that the phases of the two coincide. As a result, the output signal is output in the same phase with respect to the clock as shown in FIG. The driving-side semiconductor device of the first embodiment is characterized in that it has a shift clock generation circuit 82, and further description of other circuit portions is omitted.

  Before describing the shift clock generation circuit 82 of the first embodiment, a circuit for generating a clock accurately shifted by a predetermined phase will be described. FIG. 16 is a diagram showing a circuit configuration for generating a shift clock in which the phase of the clock CLK is shifted by 2πi / N. As shown in the figure, the combination of the delay circuit-A101 and the buffer 102, the delay circuit-B103 and the buffer 104,... N stages are connected in series. Since the same control value is applied to each delay circuit by the delay control circuit 108, the delay amount is changed simultaneously, and the delay amount of each delay circuit is the same. The phase comparison circuit 107 compares the output of the buffer 106 in the final stage set with the phase of the clock CLK. Based on the comparison result, the delay control circuit 108 matches the phase of the final stage output and the clock CLK. Change the delay amount of the delay circuit. When the output of the last stage matches the phase of the clock CLK, the output of each stage is a signal that is exactly 1 / N shifted from one cycle. Accordingly, the output of any stage may be a clock having a desired phase shift, and the number of stages is determined so that such a phase shift occurs. As described above, here, the setup time and hold time are equal, and in the normal mode, the output signal changes in synchronization with the falling edge of the clock, and the input circuit changes the input signal in synchronization with the rising edge of the clock. Since the shift clock is taken in, the shift clock may be 180 °, that is, a signal shifted by 1/2 clock cycle, and can be realized by setting the number of stages to two.

  FIG. 17 is a diagram showing the configuration of the shift clock generation circuit 82 of the first embodiment. As shown in FIG. 17, the shift clock generation circuit 82 includes first and second 1 / 2φ delay circuits 110 and 116 having the same configuration, an input stage 122, a phase comparison circuit 125, and a delay control circuit 126. And a selection circuit 127. The first and second 1 / 2φ delay circuits 110 and 116 each have the same input stage 111 or 117 as the input stage 122, a delay circuit 114 or 120 whose delay amount can be adjusted, and a buffer circuit 115 or 121. . The input stages 111, 117 and 122 are circuits having current mirror circuits (CM) 112, 118 and 123 and buffer circuits 113, 119 and 124. The current mirror circuit is a circuit for accurately capturing changes in an input signal.

  The clock output from the input stage 111 is delayed by the delay circuit-A 114 and then input to the delay circuit-B 120 via the buffer circuit 115 and the input stage 117, and is delayed by the same amount as the delay amount of the delay circuit-A 114. The phase comparison circuit 125 is input via the buffer circuit 121 and the input stage 122. The phase comparison circuit 125 compares the phase of the clock output from the input stage 111 and the phase of the clock output from the input stage 122, and the delay control circuit 126 determines that the two phases match based on the comparison result. -A114 and the delay amount of the delay circuit -B120 are changed. When the two phases match, the path from the delay circuit-A 114 to the delay circuit-B 120 via the buffer 115 and the input stage 117 and the phase comparison from the delay circuit-B 120 via the buffer 121 and the input stage 122 Since the path to the input of the circuit 125 is the same, the phase of the signal input to the delay circuit-B120 is exactly half a period shifted from the phase of the signal input to the delay circuit-A114. Therefore, the phases of the clocks output from the buffer circuits 115 and 121 are also shifted by a half cycle, the clock signal φ1 is output from the buffer circuit 121, and the half-shift clock φ1 / shifted by a half cycle is output from the buffer circuit 115. 2 is output. The selection circuit 127 is a circuit that selects which of the clock signal φ1 and the ½ shift clock φ1 / 2 is output according to the mode selection signal. When the mode selection signal indicates the normal mode, the clock signal φ1 is adjusted. When the mode is indicated, it is selected so that the 1/2 shift clock φ1 / 2 is output. As is apparent from the figure, the clock CLK input to the phase shift circuit 82 and the clock signal φ1 output from the buffer 121 have the same phase.

  Returning to FIG. 15, in the reception timing adjustment mode, the output signal generation circuit 90 outputs a dummy output signal for reception timing adjustment generated by the dummy signal generation circuit 91, and outputs each of the output circuits 88-0 and 88-1. ,..., 88-n output a dummy output signal in synchronization with the ½ shift clock φ1 / 2. The dummy output signal is, for example, a signal that changes with a clock cycle. Although not shown, the clock φ1 is output from the clock output circuit. In the reception timing adjustment mode, all other parts of the circuit operate in synchronization with the clock CLK, that is, the clock φ1, and operate in synchronization with the 1/2 shift clock φ1 / 2. Only the portion for adjusting the signal and the dummy signal generation circuit 81 are provided. The portion for adjusting the output timing performs a normal operation when the signal output from the shift clock generating circuit 82 is switched to the clock φ1, and the dummy signal generating circuit 91 is a circuit that is not required in the normal mode. Switching to normal mode will not cause any problems.

The above is the description of the driving side semiconductor device in the first embodiment. Next, the receiving semiconductor device will be described.
FIG. 18 is a diagram showing the configuration of the clock input circuit and the signal input circuit of the receiving-side semiconductor device in the first embodiment. Here, only a clock input circuit, a set of input circuits, and an input timing adjustment circuit are shown, but in reality, such a set is provided for the number of input signals, and the internal clock CLK from the illustrated clock input circuit is provided. Is supplied.

  As shown in FIG. 18, in the receiving-side semiconductor device of the first embodiment, the clock transmitted from the driving-side semiconductor device is input, and the clock-input circuit 131 that generates the internal clock CLK is transmitted from the driving-side semiconductor device. An input circuit 144 that captures the input signal as an input signal. The input signal captured by the input circuit 144 is sent to the internal circuit. This is conventional. The clock input circuit 131 includes a clock current mirror circuit 132 and a clock buffer circuit 133. The input circuit 144 includes a current mirror circuit 140, a clock buffer circuit 141, and a latch circuit 142. As described above, the current mirror circuit is used to accurately receive the transmitted signal. Conventional current mirror circuits, buffer circuits, and latch circuits are used as they are. Therefore, the description of the current mirror circuit and the buffer circuit is omitted here, but the latch circuit is related to the description of other parts and will be described later.

  In addition to the conventional configuration as described above, the receiving-side semiconductor device according to the first embodiment receives an internal clock CLK output from the clock input circuit 131 and delays it by an instructed delay amount; A delay control circuit 135 that controls the delay amount of the delay circuit 134, a 1/2 phase shift circuit 136 that outputs a clock φ1 / 2D obtained by delaying the delay clock DCLK output from the delay circuit 134 by a half cycle, and an input circuit A dummy input circuit 145 having a configuration equivalent to that of 144, and an exclusive OR (EXOR) gate 143. The dummy input circuit 145 includes a dummy current mirror circuit 137, a dummy clock buffer circuit 138, and a dummy latch circuit 139 corresponding to the current mirror circuit 140, the clock buffer circuit 141, and the latch circuit 142 of the input circuit 144. Since the clock φ1 / 2D does not require a very accurate delay amount, the 1/2 phase shift circuit 136 can be realized by connecting an appropriate number of inverters. The input signal is input to the input circuit 144 and the dummy input circuit 145. The latch circuit 142 of the input circuit 144 takes in the input signal in synchronization with the delay clock DCLK. The dummy latch circuit 139 of the dummy input circuit 145 takes in the input signal in synchronization with the clock φ1 / 2D. The signal values LD and DLD latched by the latch circuit 142 and the dummy latch circuit 139 are input to the EXOR gate 143, where an exclusive OR is calculated to determine the phase shift. The delay control circuit 135 changes the delay amount of the delay circuit 134 step by step so as to eliminate the phase shift based on the determination result of the phase shift.

  FIG. 19 is a diagram illustrating a configuration example of the delay circuit 134 and the delay control circuit 135. As shown in the figure, the delay circuit 134 includes an inverter train 151 in which a plurality of inverters are connected in series, and a plurality of AND gates 152-1 provided so that one of the inputs receives the output of every two stages of the inverter train 151. , 152-2,..., 152-n, and the output of each AND gate is applied to the gate, the source is grounded, and the drain is commonly connected. , 153-2,... 153-n, a resistor 154 connected between the signal line to which the drain of each N-channel transistor is connected in common and the high potential side of the power supply, and an input Includes a buffer 155 connected to the signal line and outputting an internal clock DCLK. The delay control circuit 135 includes an up / down counter 156 that switches between count-up and count-down according to the level of the output CLKC of the EXOR gate 143, and a decoder 157 that decodes the output of the up / down counter 156. The up / down counter 156 performs the counting operation when the mode selection signal indicates the reception timing adjustment mode and the clock φ1 / 2D rises, and either count up or count down is performed according to the value of CLKC at that time. Do. In accordance with the output of the up / down counter 156, the decoder 157 sets one of the outputs to “H” and sets the other output to “L”. When the up / down counter 156 counts up, the output position to be set to “H” is shifted to the right, and when it is counted down, the output position to be set to “H” is shifted to the left. The output of the decoder 157 is sequentially connected to the other input of each of the AND gates 152-1, 152-2, ..., 152-n, and only the AND gate to which "H" is input from the decoder 157 is activated. Is done. Of the outputs from the inverter array, the signal input to the activated AND gate is output as the internal clock DCLK, and the number of stages passing through the inverter array varies depending on which AND gate is activated. Therefore, the delay amount of the internal clock can be selected. Therefore, the adjustment unit of the delay amount control is a delay amount for two inverters. Note that the configuration shown in FIG. 19 can be used as the delay circuit and the delay control circuit shown in FIGS.

FIG. 20 is a diagram showing a circuit configuration of the latch circuit 142, and the dummy latch circuit 139 has the same circuit configuration. Since this circuit configuration is widely known, a description thereof is omitted here.
FIG. 21 is a time chart for explaining the operation of the system of the first embodiment.
In the reception timing adjustment mode, the driving-side semiconductor device 11 outputs an output signal CD that changes every cycle in synchronization with the rising edge of the clock CLK (D). On the left side, when such a signal is transmitted to the receiving-side semiconductor device 12, the input signal CQ is transmitted further later than the clock CLK (R). On the right side, the input signal CQ is transmitted to the clock CLK ( R) Shows the case where it was transmitted earlier.

  If the delay amount in the delay circuit 134 is equal to one cycle of the clock, the basic clock DCLK output from the delay circuit 134 is a signal obtained by delaying the clock CLK (R) by the delay amount in the clock input circuit 131. Is the same. Since the current mirror circuit 140 and the buffer circuit 141 are the same as the clock current mirror circuit 132 and the clock buffer circuit 133 of the clock input circuit 131, the amount of delay until the input signal CQ is input to the latch circuit 142 is the clock input circuit 131. This is the same phase relationship as when the input signal CQ is captured in synchronism with the rising edge of the clock CLK (R). For the same reason, the dummy latch circuit 139 takes in the input signal in synchronization with the falling edge of the clock CLK (R).

  As shown in the figure, the output signal CD changes every cycle in synchronization with the rising edge of the clock CLK (D). By determining the signal value acquired in synchronization with the rising edge, it can be determined whether the rising edge of the clock CLK (R) is advanced or delayed with respect to the changing edge of the input signal CQ. For example, when the input signal CQ rises, it is delayed if the signal value is “L”, advanced if the signal value is “H”, and vice versa when it falls. Since the input signal CQ changes every cycle, it can be understood how the signal changes next if the signal value of the previous half cycle is determined. In the first embodiment, this determination is performed by determining the signal value DLD of the dummy latch circuit 139.

  The outputs DLD and LD of the dummy latch circuit 139 and the latch circuit 142 change as shown, and the exclusive OR CLKC of DLD and LD changes as shown. Therefore, it is necessary to determine whether to count up or to count down after DCLK rises and LD changes until DCLK falls and DLD changes next. In the first embodiment, as shown in FIG. 19, the counting operation of the up / down counter 156 is performed according to the value of CLKC when the clock φ1 / 2D rises. That is, the determination is performed at the timing indicated by the arrow in the CLKC portion of FIG. Accordingly, when the left input signal CQ is delayed from the clock CLK (R), CLKC is “L”, and the basic clock CLK2 is advanced, so the up / down counter 156 is counted up to delay circuit 134. Increase the amount of delay in When the input signal CQ on the right side is ahead of the clock CLK (R), CLKC is “H”, and the up / down counter 156 is counted down to reduce the delay amount in the delay circuit 134. When the phase shift is eliminated by repeating the count-up or count-down, the count-up and count-down are alternately repeated. In this state, when the mode selection signal is switched to the normal mode, the clock input to the up / down counter 156 is blocked by the AND gate of FIG. 19, so the up / down counter 156 counts. Will hold the value. This state is a state in which the rising edge of the delay clock DCLK coincides with the change edge of the input signal.

  In the normal mode, the output signal CD output from the driving-side semiconductor device 11 is switched so as to change in synchronization with the falling edge of the clock CLK (D). As described with reference to FIGS. 16 and 17, since it is possible to accurately shift the half period, the rising edge of the clock CLK (D) is exactly in the middle of the changing edge of the output signal CD. In the receiving-side semiconductor device 12, the rising edge of DCLK is adjusted as described above. Therefore, when the input signal becomes a signal shifted by a half cycle, the rising edge of DCLK is just in the middle of the changing edge of the input signal CQ. . Therefore, the period during which the input signal needs to stabilize can be minimized by adding up the time required for the latch circuit 142 to set up and hold. Therefore, the clock frequency can be increased until the clock period becomes equal to this time, and the speed can be increased.

  Although an example in which the reception timing adjustment mode is provided is shown in the first embodiment, an example in which the reception timing adjustment mode is not provided in the second embodiment and the reception timing is always adjusted in the normal mode will be described. Therefore, in the second embodiment, the driving-side semiconductor device only needs to output an output signal in synchronization with the clock, and a configuration excluding the shift clock generation circuit 82 from the configuration shown in FIG. 15 may be used.

FIG. 22 is a diagram illustrating the configuration of the receiving unit of the receiving-side semiconductor device according to the second embodiment. The second embodiment corresponds to the third mode shown in FIG.
The receiving-side semiconductor device of the second embodiment takes in the clock ECLK input to the terminal 201 from the driving-side semiconductor device, and generates a ½ shift clock φ1 / 2 in which the internal clocks φ1 and φ1 are shifted by a half cycle. The generator circuit 202 and input sections 204-0, 204-1, and 204-n that capture input signals D0 to Dn synchronized with a clock ECLK input to terminals 203-0 to 203-n.

  FIG. 23 is a diagram showing a configuration of the clock generation circuit 202. In FIG. 23, reference numerals 210, 216, and 222 are input circuits -1, -2, and -3 having the same configuration, and 213 and 219 are delay circuits A and A1 having the same configuration. Are auxiliary delay circuits B and B1 having the same configuration, 215 and 221 are buffer circuits having the same configuration, 225 is a phase comparison circuit, and 226 is a delay control circuit. As is apparent from the figure, the shift clock generation circuit shown in FIG. 17 has substantially the same configuration, except that there is no selection circuit 127, both φ1 and φ1 / 2 are output, In this case, auxiliary delay circuits 214 and 220 are provided in place of 121 and output via output gabuffers 215 and 221 of delay circuits 213 and 219. Similarly to the shift clock generation circuit of FIG. 17, the clock generation circuit of FIG. 23 can output a clock signal accurately shifted by a half cycle.

  FIG. 24 is a diagram illustrating a configuration of each input unit according to the second embodiment. As shown in the figure, the configuration is similar to the configuration shown in FIG. 18, except that delay circuits 231 and 232 are separately provided to adjust the phases of the clocks φ1 and φ1 / 2. The point is that a latch 240 and a phase determination circuit 241 are provided instead of the EXOR gate 143.

  In the input circuit of the second embodiment, the normal input signal is taken in synchronization with the clock φ1, and the input signal for determining the phase shift is taken in the dummy input circuit in synchronization with the clock φ1 / 2. Do. Therefore, the clocks φ1 and φ1 / 2 supplied to the latch circuit need to be accurately shifted by a half cycle. Therefore, the delay circuits 231 and 232 are commonly controlled by the delay control circuit 233 so as to have the same delay amount, and the clocks output from the delay circuits 231 and 232 maintain the phase relationship that is accurately shifted by a half cycle. . As a result, the signal value captured by the dummy input circuit can be determined in synchronization with the clock φ1 / 2 to determine the phase shift.

  The input signal is a normal signal and is not a signal that changes in a predetermined cycle as in the first embodiment, and may or may not change. Therefore, in the second embodiment, the input signal has changed or has changed by detecting the signal value at a time point shifted by a half cycle before and after the rising edge of the clock φ1 / 2 and determining three signal values. In this case, it is determined in which direction the phase is shifted. Since the signal value at the time when the half period before and after the rising edge of the clock φ1 / 2 is shifted is a signal that normally takes the input signal, the output of the latch circuit 239 is used. Since the signal value captured when the half-cycle shifts to the front side changes when the input signal is captured when the half-cycle shifts to the rear side, it must be stored and held for one cycle before the change. There is. The latch 240 is a circuit for this purpose, and stores it immediately before the output of the latch 239 changes in synchronization with the rise of φ1, and holds it for one period until φ1 rises. The phase determination circuit 241 determines whether the input signal has changed or changes in which direction when the input signal has changed from the rising edge of the clock φ1 / 2 and the three signal values shifted by half a period before and after the rising edge. This is a circuit for determining which phase is shifted. The signal value at the time of the half cycle shift to the front side is RG0, the signal value at the time of the rising edge of the clock φ1 / 2 is RG1, and the signal value at the time of the half cycle shift to the rear side is RG2.

FIG. 25 is a circuit diagram showing a configuration of the phase determination circuit 241. The operation of the phase determination circuit 241 will be described with reference to FIGS.
When there is no phase shift, the input signal changes at the falling edge of φ1. State 1 is when the input signal remains “H” and does not change. At this time, RG0, RG1, and RG2 are all “H”, and the phase shift cannot be determined. Therefore, the count operation is not performed. Similarly, the state 2 is when the input signal remains “L” and does not change. At this time, RG0, RG1, and RG2 are all “L”, and the phase shift cannot be determined. To.

  States 3 and 4 shown in FIG. 27 are cases where the input signal changes from “H” to “L”, and the change edge of the input signal is delayed with respect to the rising edge of φ1 / 2 as in state 3. RG0, RG1, and RG2 are “H”, “H”, and “L”, respectively. In this case, the delay amounts of the delay circuits 231 and 232 are increased. When the change edge of the input signal is advanced with respect to the rising edge of φ1 / 2 as in state 4, RG0, RG1, and RG2 are “H”, “L”, and “L”, respectively. In this case, the delay amounts of the delay circuits 231 and 232 are reduced.

  States 5 and 6 shown in FIG. 28 are cases where the input signal changes from “L” to “H”, and the change edge of the input signal is delayed with respect to the rising edge of φ1 / 2 as in state 5. RG0, RG1, and RG2 become “L”, “L”, and “H”, respectively. In this case, the delay amounts of the delay circuits 231 and 232 are increased. When the change edge of the input signal is advanced with respect to the rising edge of φ1 / 2 as in state 6, RG0, RG1, and RG2 are “L”, “H”, and “H”, respectively. In this case, the delay amounts of the delay circuits 231 and 232 are reduced.

FIG. 29 is a table showing the above states, the values of RG0, RG1, and RG2 at that time, and the necessary operations.
The phase determination circuit of FIG. 25 outputs “L” as a hold signal in the states 1 and 2, “H” as the up / down signal, and “H” as the hold signal in the states 3 to 6. In the state 3 and 5, “H” is output as an up / down signal, and “L” is output as an up / down signal in the states 4 and 6. Output.

  FIG. 30 is a diagram showing the configuration of the delay circuit 231 and the delay control circuit 233 of the second embodiment. As shown in FIG. 24, a delay circuit 232 having the same configuration as the delay circuit 231 and controlled by the same control value of the delay control circuit 233 is provided, but is omitted here. As shown in the figure, the configuration of FIG. 19 has a similar configuration, except that an up / down signal is input as CLKC, a hold signal is input instead of a mode selection signal, and φ1 / 2D is replaced. In addition, a signal obtained by dividing the clock φ1 / 2 output from the delay circuit-2 by the frequency dividing circuit 159 is input. A certain amount of time is required until the delay amount in the delay circuit 134 changes due to the operation in the phase determination circuit 241 and the control value changing operation in the up / down counter 156 and the decoder 157 based on the result. Is longer than a half cycle of the clock, even if the delay amount is changed based on the determination result, the delay amount actually changes after the next determination is completed, and a feedback time delay occurs. When there is such a feedback time delay, the delay amount periodically fluctuates in the time range corresponding to two stages of the delay circuit in the vicinity of the phase matching. In this embodiment, the clock φ1 is input after being divided by the frequency dividing circuit 159 so that such a problem does not occur. As a result, feedback is performed once every several clocks, and the above problem does not occur.

  In the input circuit of the semiconductor device of the second embodiment, an operation for adjusting the phase shift is always performed during the operation of the semiconductor device. Therefore, since the operation for adjusting the phase shift is always performed during the operation of the semiconductor device, the adjustment is performed so as to automatically eliminate the phase shift even if the delay amount is changed due to a temperature change or the like. The input circuit of the semiconductor device according to the second embodiment need not perform mode switching or the like. However, since there may be a large shift immediately after system startup, it is necessary to provide an initialization period for an appropriate number of clocks and perform a calibration operation. Therefore, in the second embodiment, the initialization period is set to be equal to or longer than the number of clocks required to converge from the state of maximum deviation, the drive-side semiconductor device is provided with a dummy signal generation circuit, and the initialization period Is configured to output a periodically changing dummy signal suitable for adjusting the reception timing. The receiving-side semiconductor device adjusts the input timing adjustment circuit based on this dummy signal during the initialization period, and adjusts the input timing adjustment circuit with a normal input signal after the initialization period ends.

FIG. 31 shows the clock generation circuit of the receiving-side semiconductor device of the third embodiment, and FIG. 32 shows the configuration of the input section of the receiving-side semiconductor device of the third embodiment. The third embodiment is an example in which a part of the clock generation circuit and the input circuit of the second embodiment is changed, and the basic configuration is the same as that of the second embodiment.
As shown in FIG. 31, the clock generation circuit of the third embodiment is obtained by removing the input circuits 216 and 222 from the clock generation circuit of the second embodiment shown in FIG. Since the two input circuits 216 and 222 are removed at the same time, the path from the delay circuit 253 to the delay circuit 256 is the same as the path from the delay circuit 256 to the phase comparison circuit 259. A clock φ1 / 2 shifted by a half cycle is output. The current mirror circuit is used to capture a signal at an accurate timing. However, since the phase is adjusted in the present invention, there are few restrictions on this point, and the current mirror circuit may not be used.

  As shown in FIG. 32, the input unit (input circuit and input timing adjustment circuit) of the third embodiment is connected to the current mirror circuit 237, the buffer circuit 238, the dummy current from the input unit of the second embodiment shown in FIG. Except for the mirror circuit 234 and the dummy buffer circuit 235, a φ delay circuit 276 is provided in place of the latch circuit, and a delay circuit 278 is provided for adjusting the timing at which the delay control circuit 273 performs the count operation according to the determination result. .

  As described above, the current mirror circuit is used to capture a signal at an accurate timing. However, since the phase is adjusted in the present invention, there is little restriction on this point, and the current mirror circuit need not be used. Therefore, the current mirror circuit is excluded. The current mirror circuit consumes a large amount of power because a current always flows. However, since the current mirror circuit is not used, the power consumption can be reduced.

  In the second embodiment, the clock φ1 is divided by the frequency dividing circuit so as not to cause a problem due to feedback delay. In the third embodiment, the delay circuit 278 generates an appropriate timing signal. In addition, the count operation of the up / down counter is performed with this timing signal, so that the delay in feedback is reduced and the above problem does not occur.

In the second and third embodiments, the clock generation circuit generates an internal clock and a shift clock that is exactly ½ cycle shifted from the internal clock, and the input timing adjustment circuit includes two delay circuits for delaying each. However, as in the second mode shown in FIG. 13, it is also possible to generate a shift clock that is exactly ½ cycle shifted from the output of the delay circuit for adjusting the input timing. The fourth embodiment is such an embodiment.
FIG. 33 is a diagram showing the configuration of the input circuit and input timing adjustment circuit of the fourth embodiment. As shown in the figure, the input circuit and input timing adjustment circuit of the fourth embodiment have the same configuration as that of the circuit of the second embodiment shown in FIG. 24, except that one delay circuit is used. A shift clock generation circuit 289 for generating a shift clock from the output is provided, and the output of the buffer circuit 287 of the input circuit is input to the dummy latch 284, and the dummy current mirror circuit and the dummy buffer circuit are excluded. And a control value monitoring circuit 290 that monitors whether the control value of the delay control circuit 282 has changed. The shift clock generation circuit 289 described above is used. The input circuit and input timing adjustment circuit of the fourth embodiment operate substantially the same as the circuit of the second embodiment except for the above points.

  As described above, in the circuit of the second embodiment, the initialization period after starting the system is made sufficiently long so that the control value converges within the initialization period even from a state of maximum deviation. . In the fourth embodiment, a control value monitoring circuit 290 is provided so that fluctuations in the control value of the delay control circuit 282 can be monitored. When the input timing signal is set to the optimum state, it is considered that the control value of the delay control circuit 282 does not change. Therefore, when the control value monitoring circuit 290 detects that the same control value continues, the input timing signal Is determined to be in an optimal state.

  FIG. 34 is a diagram showing an operation mode in the fourth embodiment. A power-on reset signal is issued in response to system startup, and an initialization mode (calibration mode) is started accordingly. In the calibration mode, the driving-side semiconductor device outputs a signal whose value is switched in a predetermined cycle, and the receiving-side semiconductor device receives this and gradually changes the control value of the input timing adjustment circuit so as to reach an optimal timing. . As described above, when the input timing becomes optimal, the control value of the delay control circuit 282 does not change, and the control value monitoring circuit 290 detects that the same control value continues and turns on the control value monitoring signal. To. In response to this, the system switches the mode signal to indicate the normal mode, and normal operation is started. Even in the normal mode, the input timing adjustment circuit of the receiving-side semiconductor device performs phase comparison on the input signal and continues feedback control based on the comparison result.

  In the first to fourth embodiments described above, the phase of the input signal and the input timing signal are compared by determining the value of the input signal that has actually been captured, and the timing is adjusted to the optimum timing. . By the way, when the clock cycle becomes very short, there is a difference in the optimum input timing between when the input signal changes every clock cycle and when the same value continues.

  FIG. 35 is a diagram for explaining this problem. A solid line indicates a change in the input signal level when the input signal changes every clock cycle, and a broken line indicates a change in the input signal level when the same value continues. Indicates. As shown in the figure, when the input signal changes every clock cycle, the input signal starts changing to the next level before changing to a sufficient level. That is, the input signal changes only to an intermediate level, and the amplitude becomes small. On the other hand, when the input signal continues with the same value, the input signal changes to a sufficient level. When the signal that has continuously reached a sufficient level at the same value changes, the change in amplitude becomes larger than that in the case where the signal changes only in the previous two cycles and changes only to the middle level. There is a delay in the time it takes to pass through the level and change. Therefore, when the phase comparison is performed at the falling edge of the clock CLK, a difference is generated in the phase comparison result between the case where the value of the input signal is the same as the value changed in the previous two cycles and the result of the phase comparison. It will be. For this reason, a shift corresponding to the delay in the figure occurs depending on what input signal pattern the input timing is adjusted. Further, as shown in the figure, the optimum timing when the changed input signal is taken in also differs between the case where the value of the input signal is the same value as that in the last two cycles.

In the fifth embodiment, the problem that a difference occurs due to the input signal pattern in the above-described input timing adjustment is performed by performing phase correction only when the value of the input signal changes in the immediately preceding two cycles and performing feedback correction. To solve.
FIG. 36 is a diagram illustrating the configuration of the input circuit and the input timing adjustment circuit of the receiving-side semiconductor device according to the fifth embodiment. As shown, the input circuit and the input timing adjustment circuit of the fifth embodiment are similar to the input section of the second embodiment shown in FIG. 24, and a latch 307 for further latching the output of the latch 306 is provided. The output is given to the phase determination circuit 308 as RG3. Since the latch 307 takes in the output of the latch 306 in synchronization with the input timing signal output from the delay circuit-1 in the same manner as the latch 306, it performs the role of holding the output of the latch 306 for one more clock cycle. Further, as a timing for changing the control value of the delay control circuit 303, a signal obtained by delaying the output of the delay circuit 301 by the delay circuit 309 is input, which is the same as the input unit of the third embodiment shown in FIG. It is.

  FIG. 37 is a diagram for explaining the relationship among the pattern of the input signal, the fetch value of each latch, and the phase determination in the fifth embodiment. The latches 305, 306, and 307 take the input signal and the previous stage output in synchronization with the input timing signal, and output them as RG2, RG0, and RG3. Since the input signal is taken in and output as RG1, RG0, RG1, RG2, and RG3 have the relationship shown in the figure. Qa represents an input signal that remains “high (H)” or “low (L)” and does not change, Qb represents an input signal that has changed in the previous cycle, but has not changed in the immediately preceding cycle, Qc and Qd do not change in the previous cycle, but represent the input signal changed in the immediately preceding cycle, Qc indicates that the phase of the input timing signal DCLK is advanced, and Qd indicates the phase of the input timing signal DCLK. Qe and Qf represent the case where the phase of the input timing signal DCLK is advanced, Qe represents the case where the phase of the input timing signal DCLK has advanced, and Qf represents the phase of the input timing signal DCLK. It represents the case where it is late. As described above, in the fifth embodiment, the phase is compared and the feedback correction is performed only when the value of the input signal has changed in the last two cycles. Therefore, in the case of the input signal Qe, the input timing signal DCLK The control value of the delay control circuit 303 is changed so as to delay the input timing signal DCLK, and the control value of the delay control circuit 303 is changed so as to advance the input timing signal DCLK. The control value of the delay control circuit 303 is maintained.

  FIG. 38 is a circuit diagram of the phase determination circuit 308, and FIG. 39 is a truth table thereof. Since the circuit of FIG. 38 provides the truth table of FIG. 39, the hold signal becomes “low (L)” only when the input signals are Qe and Qf of FIG. 37, and delay control is performed according to the up / down signal. When the control value of the circuit 303 is changed and the input signals are Qa to Qd in FIG. 37, the hold signal becomes “high (H)” and the control value of the delay control circuit 303 is maintained.

  As described above, the optimum timing for capturing a changed input signal also differs between the case where the value of the input signal is the same value as the case where the value of the input signal is changed in the previous two cycles. In the sixth embodiment, after adjusting the input timing as in the fifth embodiment, if the input signal has a different value in the previous two cycles, the input signal is captured in synchronization with the input timing signal. If the values are the same in the previous two cycles, the next input timing signal is fetched with a predetermined delay.

  FIG. 40 is a diagram showing the configuration of the input circuit of the sixth embodiment. The fifth embodiment of FIG. 36 is different from the fifth embodiment in that an input timing signal supplied to the latch 305 is provided with a switch 310 and a correction delay circuit 311. The difference is that it is possible to select whether or not DCLK is delayed by a predetermined amount in accordance with the correction control signal H1. 41 is a diagram showing the configuration of the switch 310 and the correction delay circuit 311 of the sixth embodiment. The transfer gates 321 and 322 and the inverter 323 constitute the switch 310, and the two-stage inverters 324 and 325 are the correction delay. The circuit 311 is configured. The correction control signal H1 output from the phase determination circuit 308 becomes “L” when the value of the input signal changes in the last two cycles, and becomes “H” when the value is the same. When the correction control signal H1 is “L”, the transfer gate 322 is in a passing state, and the input timing signal DCLK is input to the latch 305 without delay, and when the correction control signal H1 is “H”, the transfer gate 321 is passed. The input timing signal DCLK is delayed by the two-stage inverters 324 and 325 and input to the latch 305.

  FIG. 42 is a diagram showing a configuration of the phase determination circuit 312 of the sixth embodiment, and FIG. 43 is a truth table thereof. As is apparent from comparison with FIGS. 38 and 39, the phase determination circuit 308 of the fifth embodiment is added with a function for determining whether the value of the input signal is different in the immediately preceding two cycles. In the case of Qa, Qc and Qd having different input signal values, the correction control signal H1 becomes “H”, and in the case of Qb, Qe and Qf having the same input signal value in the previous two cycles, correction is performed. The control signal H1 becomes “L”.

  In the first to sixth embodiments described so far, the receiving-side semiconductor device has a basic configuration as shown in FIG. 8, and an input timing adjustment circuit is provided for each input circuit so that each input signal is provided. It was adjusted so that it could be taken in at the optimal timing. Therefore, there arises a problem that the phases of signals output from the respective input circuits are different. FIG. 44 is a diagram for explaining such a problem. 44, the input signals at the time of input to the input circuits 53-0, 53-1,..., 53-n are Q0, Q1, Q2, and the output of each input circuit is input to the internal circuit 55 These signals are represented by Q00, Q10, and Q20. When the phases of the input signals Q0, Q1, and Q2 are shifted as shown in the figure, the input timing adjustment circuits 54-0, 54-1, ..., 54-n are connected to the input circuits 53-0, 53-1, .., 53-n adjust the phase of the internal clock so that the input signals Q0, Q1,..., Qn are fetched at the most appropriate timing. The phases of Q10 and Q20 are similarly shifted. FIG. 45 is a diagram showing what cycle the signals Q00, Q10, and Q20 are in one clock cycle, and t0 to t4 represent the timing shown in FIG. As shown in FIG. 45, between t0 and t1, Q00 and Q20 become signals Q0B and Q2B in the same cycle, but Q10 becomes a signal Q1A in the previous cycle. Similarly, between t2 and t3, Q00 and Q10 become signals Q0B and Q1B in the same cycle, but Q20 becomes a signal Q2C in the next cycle. If the processing based on the signal between t0-t1 and t2-t4 is performed in the internal circuit 55, the processing is performed on a different set of signals, and erroneous processing is performed. The problem of becoming.

In the embodiment described below, this problem is solved, and even if the phase of the clock and the signal is shifted on the receiving side, the clock input circuit and another signal input circuit are positioned within the semiconductor device on the receiving side. Even when a phase difference occurs, high-speed signal delivery is possible.
FIG. 46 is a diagram showing a basic configuration of a semiconductor device according to a seventh embodiment of the present invention. As shown in FIG. 46, in addition to the basic configuration of the present invention shown in FIG. 8, the semiconductor device of the seventh embodiment detects the phase difference between the output signals of the input circuits so as to have the same phase. And an inter-signal timing adjustment circuit for adjusting the signal. It is assumed that the semiconductor device system of the seventh embodiment is a system as shown in FIG.

FIG. 47 is a diagram showing the configuration of the clock input circuit, the input unit, and the inter-signal timing adjustment circuit of the receiving-side semiconductor device in the seventh embodiment.
As shown in FIG. 47, the receiving-side semiconductor device of the seventh embodiment has a clock input circuit 142 that receives a clock transmitted from the driving-side semiconductor device and generates internal clocks φ and φ1 / 2, and a driving-side semiconductor. , 144-n that takes in signals transmitted from the apparatus as input signals, AND gate 401 that calculates the logical product of the outputs of the input units, delay circuit 402, and delay control Circuit 403, latch pulse generation circuit 404, and latch circuits 405-0, 405 for latching the outputs of the input sections 144-0, 144-1,..., 144-n in accordance with the latch pulse QSYN output from the latch pulse generation circuit 404. -1, ..., 405-n. The clock input circuit 142 and the input sections 144-0, 144-1,..., 144-n are the same as in the second embodiment, and the clock input circuit 142 has a configuration as shown in FIG. The unit has a configuration as shown in FIG. Therefore, in the input circuit of the semiconductor device of the seventh embodiment, an operation for adjusting the phase shift can be performed at all times during the operation of the semiconductor device. However, in the seventh embodiment, the mode signal is input and the adjustment operation is performed only in the input timing adjustment mode.

  48 is a diagram illustrating the configuration of the delay control circuit 403 in FIG. 47, FIG. 49 is a diagram illustrating the configuration of the delay circuit 402 and the latch pulse generation circuit 404, and FIG. 50 is a time diagram illustrating the operation of the delay control circuit 403. It is a chart. As shown in FIG. 47, the output QAND of the AND gate 401 is “when the outputs Q00, Q10,..., Qn1 of the input units 144-0, 144-1,. H ". The input signal input in the reception timing adjustment mode changes in a pattern that becomes “H” only in a specific cycle while “low (L)” continues. When Q00, Q10,..., Qn1 all become “H” in the part of the cycle that becomes “H”, a QAND becomes an “H” pulse. The rising edge of QAND is the timing at which the most delayed input signal rises, and the period in which QAND is “H” indicates a period in which Q00, Q10,..., Qn1 are all signals of the same cycle. Therefore, if the outputs of the input units 144-0, 144-1,..., 144-n are latched by the latch circuits 405-0, 405-1,. become. 48, the signals a0, a1,..., Am are gradually delayed and changed as shown in FIG. When QAND rises, the flip-flop F / F latches the signals a0, a1,..., Am, but the value latched differs at the timing when QAND rises. For example, b0, b1,..., Bm in FIG. 48 are “H” up to b1, and “L” thereafter. When such a signal is input to the NOR gate row of FIG. 48, only the output at the change point becomes “H”. In FIG. 23, only c2 is “H”. When such signals c 0, c 1,..., Cn are input to the delay circuit 402, only the NAND gate of the delay circuit whose c is “H” is in a passing state. The delay amount of the clock φ is determined at the position of the NAND gate that is in the passing state. The final NOR gate generates a pulse QSYN having a predetermined width from the rising edge of the clock φ. In this way, immediately after QAND rises, QSYN is output, and the latch circuits 405-0, 405-1,..., 405-n are input units 144-0, 144-1 within the period when QAND is “H”. ,..., 144-n, and outputs Q00, Q10,.

  FIG. 51 is a diagram for explaining the principle of adjusting the input timing in the semiconductor device of the seventh embodiment. As shown in FIG. 51, the input signals Q0, Q1,..., Qn are shifted from each other at the same time as the clock CLK (R). When capturing such an input signal, it is necessary to capture when the input signals Q0, Q1,. That is, it is desirable to latch at the time indicated by the dots in the figure. Therefore, the input circuit adjusts the phase of the internal clock so as to be latched at the time indicated by the dots, and outputs Q00, Q10,..., Qn0. For one pulse signal, as shown in the figure, when Q00, Q10,..., Qn0 all become “H”, QAND becomes “H”. ,..., Qn0 are latched by the latch circuit at the subsequent stage when all of them are prepared.

  FIG. 52 is a diagram showing input timing adjustment according to the seventh embodiment. As shown in the figure, the input signals Q0, Q1,..., Qn have a limited period of stability, but each input circuit captures an input signal in this limited stable period, and Q00, Q10,. Qn0 is output. Next, when the signals of the same cycle of Q00, Q10,..., Qn0 are gathered, QSYN is output, and the signal of the same cycle is latched by the next stage latch circuit and output as Q01, Q11,. .

  FIG. 53 is a diagram showing the entire configuration of the semiconductor device of the seventh embodiment, and shows the case of SDRAM as an example. The SDRAM 400 includes a control signal input circuit 411 to which / RAS, / CAS, / WE and the like are input, an address signal input circuit unit 412 to which an address signal is input, a clock generation circuit 413 to which a clock CLK is input, and data A data signal input circuit portion 414 to which a signal is input, a mode register / decoder 415, and an inter-signal timing adjustment circuit 416 are provided. The circuit of the first embodiment described so far is applied to the data signal input circuit unit 414 and the inter-signal timing adjustment circuit 416. As described above, it is a data signal that needs to be input / output at high speed in the SDRAM, and other control signals and address signals may be input / output at a lower speed than the data signal. . Therefore, the mode instruction signal is a signal terminal to which a signal is input at a relatively low speed, that is, a control signal and an address signal are combined, and the mode register / decoder 415 indicates a mode register set from the control signal. Then, the processing content is determined from the value of the address signal.

  FIG. 54 is a diagram for explaining operation mode determination and input timing adjustment mode in the seventh embodiment. As shown in the figure, when the mode register set is instructed by the control signal, the mode register / decoder 415 decodes the process of adjusting the input timing by the address signal, and performs the process of adjusting the input timing described so far. Be started. When the mode register set is instructed again by the control signal and the instruction to end the process of matching the input timing is instructed by the address signal, the timing adjustment is stopped and the adjustment value at that time is maintained.

FIG. 55 is a diagram showing a modification in which another signal input terminal is provided to instruct the input timing adjustment mode. When a RESET signal is input, the SDRAM is reset, and a new input timing adjustment mode is provided. Is started.
FIG. 56 is a diagram for explaining the operation mode determination and the input timing adjustment mode in this modification. It is the same as FIG. 54 except that the input timing adjustment mode is instructed by the RESET signal.

  FIG. 57 is a diagram showing the configuration of the semiconductor device of the eighth embodiment. Unlike the seventh embodiment, delay circuits 431-0, 431-1,..., 431-n are provided instead of the latch circuits 405-0, 405-1,. Along with this, a delay control register 430 is provided. Also, the delay circuit 402 and the delay control circuit 403 of the seventh embodiment are omitted, and a register 432 for receiving these input signals in the internal circuit is shown. In addition to QAND, outputs Q00, Q10,..., Qn0 of each input circuit are input to the delay control register 430. The delay control register 430 performs control to set the delay amount in each of the delay circuits 431-0, 431-1,..., 431-n so as to match the slowest signal among Q00, Q10,. Therefore, the delay control register 430 calculates the exclusive OR of QAND and Q00, Q10,..., Qn0, calculates and stores the delay amount of Q00, Q10,. A delay amount in the circuits 431-0, 431-1, ..., 431-n is set.

  The adjustment of the input signal reception timing is performed in the adjustment mode, and the adjustment value is maintained after the adjustment mode is completed. To recognize the adjustment mode, a mode register / decoder for recognizing a mode instruction signal input from the outside is provided. During the reception timing adjustment mode, a signal having a predetermined signal pattern is output from the driving-side semiconductor device. This pattern is, for example, a pattern in which the same logical value becomes a different logical value only in a specific cycle while it continues.

  In SDRAM, it is a data signal that needs to be input / output at a high speed, and other control signals and address signals may be input / output at a lower speed than the data signal. Therefore, the mode instruction signal may be combined with a signal terminal to which a signal is input at a relatively low speed, that is, a long cycle input signal value. Further, a dedicated input signal terminal for inputting a mode instruction signal may be provided. As the mode instruction signal, for example, a reset signal may be used, and when the reset signal is input, the adjustment mode may be automatically entered for a predetermined period. In this case, it is desirable that an input signal having a predetermined signal pattern is input for a predetermined period even after the end of the reception timing adjustment mode is instructed.

  FIG. 58 is a diagram showing the basic configuration of the semiconductor device according to the ninth embodiment of the present invention. As shown in FIG. 58, in the semiconductor device according to the ninth embodiment of the present invention, the input circuit section includes input buffers 441-0, 441-1,..., 441-n such as current mirror circuits. Is provided with a timing adjustment fetching circuit 443 that takes in after adjusting the delay amount of the output of each input buffer so that the output can be optimally taken in with a predetermined internal clock. Timing adjustment fetch circuit 443 is a combination of timing adjustment circuits 445-0, 445-1,..., 445-n and timing control circuits 444-0, 444-1,. Is provided for each input signal. More specifically, this combination delays the outputs of the input buffer circuits 441-0, 441-1,..., 441-n, and a delay circuit capable of selecting the delay amount, and the input buffer in synchronization with the internal clock. Based on the signal input circuit that captures the output of the circuit, the phase determination circuit that determines the phase of the output of the input buffer circuit relative to the internal clock by determining the output signal value of the signal input circuit, and the determination result of the phase determination circuit A delay control circuit for controlling the delay amount of the delay circuit so that the output of the input buffer circuit has a predetermined phase with respect to the internal clock.

  FIG. 59 is a diagram showing the configuration of the semiconductor device according to the ninth embodiment. A difference from the seventh embodiment is that an inter-signal timing adjustment circuit 455 is arranged near a register 456 that receives an input signal in an internal circuit, and timing adjustment latch circuits 454-0, 454-1,. -N and a shift clock generation circuit 453 are arranged, and only current mirror circuits 452-0, 452-1, ..., 452-n are arranged in the input section. Even if the inter-signal timing adjustment circuit 455 adjusts the phase of each signal to be the same, if the distance from the inter-signal timing adjustment circuit 45 to the register 456 is long, a phase difference may occur between them. Therefore, it is desirable to arrange the inter-signal timing adjustment circuit 455 near the register 456. It is better to arrange the input circuit for taking in the input signal in the vicinity. Therefore, in the ninth embodiment, the input circuit of the seventh embodiment is divided into a current mirror circuit and a timing latch circuit for adjusting and latching the input timing, and current mirror circuits 452-0, 452-1,. 452-n are arranged in the vicinity of the signal terminals, and the timing latch circuits 454-0, 454-1, ..., 454-n are arranged in the vicinity of the inter-signal timing adjustment circuit 455. Accordingly, it is desirable to arrange the shift clock generation circuit 453 in the vicinity of the timing latch circuits 454-0, 454-1,.

FIG. 60 is a diagram for explaining input timing adjustment in the ninth embodiment. The only difference from the operation of the seventh embodiment shown in FIG. 52 is that the input signal is sent to the internal timing latch circuits 454-0, 454-1,. It is.
FIG. 61 is a diagram showing the configuration of the semiconductor device according to the tenth embodiment. In this embodiment, as in the ninth embodiment, current mirror circuits 452-0, 452-1,..., 452-n are arranged near the input signal terminal, but the timing adjustment latch circuit 454-0 is arranged. , 454-n and inter-signal timing adjustment circuit 455, instead of timing adjustment latch circuits 458-0, 458-1,.

  62 is a diagram showing one configuration of the timing adjustment latch circuits 458-0, 458-1,... 458-n. This timing adjustment latch circuit does not delay the clock, but adjusts the delay amount of the input signal to adjust the phase of the input signals Q0Z, Q1Z,..., Q2Z to the clocks φ and φ1 / Match the phase of 2. The delay circuit 460, the delay control circuit 461, the latch circuits 462, 463, and 464, and the phase determination circuit 465 are the same as those shown in FIG. Therefore, further detailed explanation is omitted.

  FIG. 63 is a diagram showing timing adjustment in the tenth embodiment. Q0, Q1, Q2 are input signals to the current mirror circuits 452-0, 452-1,..., 452-n, and Q0Z, Q1Z, Q2Z are timing adjustment latch circuits 454-0, 454-1,. In the input signal to n, Q00, Q10, and Q20 indicate a state in which the phases are aligned inside the timing adjustment latch circuit, and Q01, Q11, and Q21 indicate outputs from the timing adjustment latch circuit. As shown in the figure, the timing adjustment latch circuits 454-0, 454-1,... The signals output from the adjustment latch circuit are in phase. As described above, in the semiconductor device of the tenth embodiment, the delay amount of the input signal is adjusted so as to be optimally captured with a predetermined internal clock. Therefore, even when there are a plurality of input signals, if this adjustment is performed for each input signal, the phases of all the input signals are aligned, so that no further timing adjustment is necessary.

  FIG. 64 shows a case where the deviation (skew) between the input signals is one clock cycle or more. In this case, as in the seventh embodiment, the outputs Q00, Q10,..., Qn0 obtained by inputting these input signals in the input circuit do not overlap with each other in the same cycle. Therefore, in the configuration shown in FIG. 47, QAND does not become “H”, and the phases cannot be aligned between the input signals. The eleventh embodiment is an embodiment that solves this problem.

FIG. 65 is a diagram showing the configuration of the eleventh embodiment. The difference from the configuration of the seventh embodiment is that a delay circuit 502, a ½ divider circuit 503, and latch circuits 504 and 505 are added to the input circuit 501, and QSYNCA, This is the point where QSYNC and QSYNC are output.
FIG. 66 is a diagram for explaining the operation of the semiconductor device according to the eleventh embodiment. The operation of the eleventh embodiment will be described with reference to this figure.

  The ½ divider circuit 503 outputs a ½ divided clock of the opposite phase obtained by dividing the clock by ½, and the latch circuits 504 and 505 are connected to the input circuit 501 according to the ½ divided clock of the opposite phase. Since the output is latched, the latch circuit 504 latches Q00A, and the latch circuit 505 latches Q00B. The same applies to other input signals. When the outputs of the latch circuits 504 and 505 are taken by the OR gate 506-0, a signal indicating a period in which Q00A and Q00B are “H” is outputted. In other words, an input signal spread over three clock cycles is output. Therefore, when this is input to the AND gate 507, the output QAND indicates a period in which the input signals spread over three clock cycles overlap. If the phase difference of the input signals is 3 clock cycles or less, QAND changes to “H”. Thereafter, QSYNA is generated as in the first embodiment. The latch circuits 504 and 505 hold the latched input signal for two clock cycles, and the signals output from the latch circuits 504 and 505 are signals shifted by one clock cycle. The latch circuit 511-0 performs an operation of holding the signal output from the latch circuit 504 for one more clock cycle. Since the outputs of the latch circuits 504 and 505 and the output of the latch circuit 511-0 are input to the latch / select circuit 512-0, the latch / select circuit 512-0 depends on the delay amount of each input signal. Select one of the latches. QSYNC and QSYNC are latch signals for this purpose.

  FIG. 68 is a diagram showing input signals of the twelfth embodiment. In the twelfth embodiment, a data signal is input at a frequency twice that of the clock CLK. The once captured data signal is processed by converting two continuous data signals into parallel data signals. In the twelfth embodiment, this change is made using the configuration shown in the eleventh embodiment.

FIG. 69 is a diagram showing the configuration of the semiconductor device of the twelfth embodiment. The difference from the eleventh embodiment is that the latch / select circuits 512-0,..., 512-n output two continuous signals. And latch circuits 513-0,..., 513-n for latching the points.
70 and 71 are diagrams for explaining the operation of the semiconductor device of the twelfth embodiment. The operation of the twelfth embodiment will be described with reference to this figure.

  Latch circuit 511-1 outputs Q01B with a delay of one clock cycle with respect to Q01A. The latch / selection circuits 512-0,..., 512-n output the same clock cycle signal in phase. That is, the signal Q01B of the next clock cycle is output with a delay of one clock cycle with respect to Q01A. However, Q01A and Q11A have the same phase, and Q01B and Q11B have the same phase. The latch circuits 513-0,..., 513-n latch in synchronization with QSYNC, so that the phases of Q02A, Q02B, Q12A, Q12B output from the latch circuits 513-0,. Match all. Thereby, the conversion which makes a signal parallel is performed.

  FIG. 72 is a diagram showing the configuration of the thirteenth embodiment. In the thirteenth embodiment, the input timing can be adjusted even when the phase of the input signal is shifted by one clock cycle or more in the tenth embodiment. As shown in FIG. 72, the signal input to the 1/2 frequency divider 521 that divides the output of the current mirror circuit 452 by 1/2 and the timing adjustment lit circuit 455 A switching circuit 522 that switches between the output of the divide-by-2 circuit 521 is provided. In this case, at the initial stage of the reception timing adjustment mode, switching is performed so that the output of the 1/2 frequency divider circuit is input to the timing adjustment lit circuit 455, and then the output of the current mirror circuit 452 is input to the timing adjustment lit circuit 455. Switch as follows. In this case, in the reception timing adjustment mode, a signal having a pattern that changes at a period of 4 clock cycles or more is input as an input signal.

  In the seventh to thirteenth embodiments described above, an input signal that changes in a predetermined pattern is required to resynchronize an input signal that has been input and adjusted in timing. Therefore, it is necessary to provide an adjustment mode and output a signal that changes in such a pattern from the drive side in the adjustment mode. The amount of delay in the circuit changes according to temperature changes and power supply voltage changes. For this reason, it is necessary to periodically provide an adjustment mode, capture an input signal at an optimal timing, and resynchronize even if such a change occurs. However, without providing such an adjustment mode, it is desirable to be able to perform resynchronization while taking in an input signal at an optimal timing by always performing feedback control.

  As described above, in the second to sixth embodiments, feedback adjustment can be performed so as to capture an input signal at an optimal timing without providing an adjustment mode. Therefore, if resynchronization can be performed regardless of the input signal, it is possible to always perform feedback control and capture the input signal at an optimal timing and to resynchronize. The fourteenth embodiment is an embodiment that enables this. In the fourteenth embodiment, paying attention to the fact that the input timing signal in each input circuit corresponds to the phase of the signal output from the input circuit, the latest input signal is detected using the input timing signal.

  FIG. 73 is a diagram showing a configuration of the receiving-side semiconductor device according to the fourteenth embodiment. As shown, the semiconductor device of the fourteenth embodiment is the same as that of the seventh embodiment shown in FIG. 47 except that the signal input to the AND gate 401 is a signal DK0,. The same. FIG. 74 is a diagram showing the configuration of the input circuit of the fourteenth embodiment. As shown in the figure, the circuit is the same as the circuit shown in FIG. 24 except that a 1/2 frequency dividing circuit 521 is provided.

  FIG. 75 is a diagram for explaining the operation of the semiconductor device according to the fourteenth embodiment. Each input timing signal DCLK is a signal having the same cycle as the clock, which rises immediately before the output Q00, Q10,..., Qn0 of each input circuit changes. Therefore, when the input timing signal DCLK is frequency-divided by the 1/2 frequency divider 521, the signals DK0,..., DKn change in substantially the same manner as Q00, Q10,. Here, if the signals DK0,..., DKn have the same phase at the power-on reset, the signals DK0,..., DKn change at a cycle twice that of the clock that changes at the rising edge of the input timing signal DCLK. Signal. Therefore, if the signals DK0,..., DKn are input to the AND gate 401, resynchronization can be performed as in the seventh embodiment.

When an input signal taken in by the input circuit is supplied to the internal circuit, it is desirable to provide the inter-signal timing adjustment circuit in the vicinity of the internal circuit. Further, the input unit may be an input buffer such as a current mirror circuit, and the latch circuit and the input timing adjustment circuit may be provided in the vicinity of the internal circuit.
It is desirable that a plurality of input timing adjustment circuits be arranged together and share a delay circuit or the like for adjusting the clock phase. Thereby, the circuit scale can be reduced.
When the phase shift of the input signal is 1 clock cycle or more, there is no state in which the outputs of the plurality of input circuits all overlap, and the logical product does not change. For this reason, in such a case, the input circuit is provided with a parallel conversion circuit that takes in the input signal and converts two consecutive signals of the input signal into a parallel signal, and detects a period in which the outputs overlap. Like that. The inter-signal timing adjustment circuit adjusts the output of the parallel conversion circuit so that signals in the same cycle have the same phase. Further, in the SDRAM, the cycle of the data signal is shorter than the cycle of the clock, and there is a case where a set of signals having a plurality of consecutive input signals is formed. In such a case, this parallel conversion circuit is used to convert a continuous input signal into a parallel signal. In this case, the inter-signal timing adjustment circuit adjusts the outputs of the pair of parallel conversion circuits so as to have the same phase.

As described above, in the seventh to thirteenth embodiments, the phase shift is eliminated even if there is a phase shift between the received clock and the input signal due to the difference in the transmission time of the signal path. In addition, since there is no phase shift in the signal that is captured and output after being captured, malfunction or the like does not occur.
As shown in FIG. 8, the receiving-side semiconductor device in the first to thirteenth embodiments has an input timing adjustment circuit for each input circuit. As a result, even when there is a skew between the input signals, the input signals can be captured at the optimum timing. However, such a semiconductor device has a problem that the circuit becomes large because it is necessary to provide an input timing adjustment circuit for each input signal. In the semiconductor device system, there are many examples in which the skew between the clock and the input signal group is large but the skew between the input signals is small due to the relationship between the wiring and the load. In such a case, the input timing adjustment circuit described so far for one typical input signal may be provided, and the other input signals may be captured in synchronization with the same input timing signal. If this is the case, the circuit scale can be greatly reduced, and an input signal can be fetched at almost optimum timing.

  Further, in the semiconductor device system, as shown in FIG. 1, the wiring between the driving side semiconductor device 11 and the receiving side semiconductor device 12 is arranged in parallel as much as possible to reduce the skew between signals as much as possible. Yes. Therefore, the skew between the clock input to the terminal of the receiving semiconductor device and the input signal may be small enough to be ignored. Since the internal circuit of the receiving-side semiconductor device operates in synchronization with the internal clock generated from the received clock, it is necessary to distribute the internal clock to various internal locations, and each unit operates in synchronization with the internal clock. Therefore, the distributed internal clock needs to have a small phase difference. When the number of internal clock distribution is large and distributed in the device, the wiring length from the internal clock generation circuit to the distribution destination becomes long, and it is necessary to provide a large number of clock buffers along the way. The clock causes a large delay with respect to the input clock. When the input circuit captures the input signal in synchronization with the delayed internal clock, even if the skew between the clock and the input signal is small at the input terminal, the input circuit captures the input signal, that is, the input timing. There will be a large phase difference between the signal and the input signal. In such a case, as described above, it is conceivable that the input timing adjustment circuit described so far is provided for one typical input signal, and the input signal is captured in synchronization with the input timing signal adjusted there. However, in order to be able to adjust the input timing, it is necessary to provide a shift clock generating circuit as shown in FIG. 16 on either the driving side or the receiving side, and further to adjust the input timing having a delay circuit and a delay control circuit. There is a problem that the circuit scale for this is large. Therefore, it is required to realize a circuit for adjusting the input timing on the smallest possible scale.

  When the phase difference between the clock distributed by the clock distribution system and the input signal as described above is a problem, the clock distribution system has a considerable circuit scale. Varies with the power supply voltage. For this reason, the above phase difference may vary depending on the environment, and it is not possible to capture an input signal with good timing only by shifting the timing by a certain amount. This phase difference is a delay in the distribution system that distributes the internal clock within the semiconductor device. In other words, it can be said to be a phase difference between the input clock and the distributed clock. Therefore, in the fifteenth embodiment, adjustment is made to eliminate the phase difference between the input clock and the distributed clock.

FIG. 76 is a diagram showing the configuration of the internal clock generation circuit and the signal input circuit of the receiving-end semiconductor device according to the fifteenth embodiment of the present invention.
In FIG. 76, reference numeral 610 is a clock generation circuit for generating the internal clock CLK2 from the external clock CLK, 620 is a dummy input circuit, and 630 is a signal input circuit. In FIG. 76, only one signal input circuit is shown, but there are as many input signals as there are input signals. One dummy input circuit 620 is provided in common for all signal input circuits. However, the dummy input circuit 620 may be provided for each set of signal input circuits or for each signal input circuit. Similar to the conventional clock input circuit, the clock generation circuit 610 includes a clock current mirror circuit 611 for accurately receiving the input external clock CLK, and a clock buffer circuit 612 for buffering the output of the clock current mirror circuit 611. And a delay control circuit 614 for controlling the delay amount in the delay circuit 613.

  Similar to the conventional signal input circuit, the signal input circuit 630 includes a current mirror circuit 631 that receives an input signal, an input buffer circuit 632, and a latch circuit 633. The signal input circuit 630 is generally provided near the signal input terminal, and is also provided near the signal input terminal in this embodiment. The dummy input circuit 620 is a circuit having a configuration equivalent to that of the signal input circuit 630, and a dummy current mirror circuit 621 corresponding to the current mirror circuit 631 to which the external clock CLK is input, the input buffer circuit 632, and the latch circuit 633. A dummy input buffer circuit 622 and a dummy latch circuit 623. The dummy input circuit 620 is also provided near the clock input terminal to which the external clock CLK is input. Conventional current mirror circuits, buffer circuits, and latch circuits are used as they are. Therefore, description of the current mirror circuit and the buffer circuit is omitted here. The latch circuit has a configuration as shown in FIG. 20, and the delay circuit 613 and the delay control circuit 614 have a configuration as shown in FIG.

FIG. 77 is a time chart showing the operation of FIG.
As shown in FIG. 77, the input signal is input so as to be effective before and after the rising edge of the external clock CLK. The output CLK0 of the clock current mirror circuit 611 and the output CLK1 of the clock buffer circuit 612 are as shown in the figure due to delays in the respective circuits. As indicated by the dashed arrow, CLK1 is delayed by about one cycle of the clock by the delay circuit 613 and output. The effective period of the output SIG0 of the current mirror circuit 631 and the output SIG1 of the input signal buffer circuit 632 is as shown in the figure because the input signals are delayed in the respective circuits. Although the external clock CLK is input to the dummy current circuit 621, the dummy current circuit 621 and the dummy buffer circuit 622 generate the same delay as the delay amount of the current mirror circuit 631 and the input signal buffer circuit 632, so that the output DCLK0 DCLK1 is as shown. That is, DCLK1 rises at an optimal timing with respect to the effective period of SIG1. Therefore, the delay amount in the delay circuit 613 may be adjusted so that the internal clock CLK2 rises at the same timing as DCLK1.

  In the dummy latch circuit 623, DCLK1 is latched according to the internal clock CLK2. Since the output CLKC of the dummy latch circuit 623 differs depending on whether DCLK1 rises before or after the internal clock CLK2, the up / down counter of the delay control circuit 614 is counted up or down according to CLKC, and the internal clock CLK2 is The delay amount in the delay circuit 613 is feedback adjusted so that it rises at the same timing as DCLK1.

78 is a time chart showing a case where DCLK1 is advanced with respect to the internal clock CLK2, and FIG. 79 is a time chart showing a case where DCLK1 is delayed with respect to the internal clock CLK2.
As shown in FIG. 78, it is assumed that the input signal is valid for an appropriate period before and after the rising edge of the external clock CLK. It is assumed that DCLK1 output from the dummy buffer circuit 622 is advanced by a with respect to the internal clock CLK2 output from the clock generation circuit 610 and input to the dummy latch circuit 623. In this case, the output CLKC of the dummy latch circuit 623 changes as shown, and is the period “H” during which the internal clock CLK2 is “H”. The delay control circuit 614 reduces the delay amount in the delay circuit 613 when CLKC is “H” and the internal clock CLK2 falls. As a result, the internal clock CLK2 changes so as to coincide with the rising edge of DCLK1. On the contrary, as shown in FIG. 79, when DCLK1 is delayed by b with respect to the internal clock CLK2, CLKC is “L” over almost the entire period as shown. The delay control circuit 614 increases the delay amount in the delay circuit 613 when CLKC is “L” and the internal clock CLK2 falls. As a result, the internal clock CLK2 changes so as to coincide with the rising edge of DCLK1.

  As described above, in the fifteenth embodiment, an external clock is input to a dummy input circuit equivalent to the signal input circuit, and the input signal is latched by the internal clock from the value when latched by the internal clock. Because the timing is detected to be shifted to the optimal timing based on the detection result, the input signal is always captured at the optimal timing regardless of temperature conditions and power supply voltage. Can do.

  FIG. 80 is a diagram showing the configuration of the clock generation circuit and the signal input circuit of the semiconductor device according to the sixteenth embodiment. A difference from the fifteenth embodiment is that a clock distribution circuit 640 for distributing the internal clock generated by the clock generation circuit 610 to each part in the semiconductor device is provided, and the internal clock distributed from the clock distribution circuit 640 is provided. Are input to the dummy input circuit 625 and the signal input circuit 635, and the dummy input circuit 625 and the signal input circuit 635 are of a latch type in which the external clock CLK or the input signal is directly input to the latch circuit.

  As already described, the reason that the current mirror circuit is used in the portion that receives the signal from the outside is to capture the change of the signal accurately. Since the error when the signal is captured becomes the timing error as it is, a current mirror circuit that can accurately capture the change of the signal has been used conventionally. Although the current mirror circuit can accurately capture a change in signal, there is a problem in that power consumption increases because a current always flows. By applying the present invention, the input signal is adjusted so as to be captured at a predetermined appropriate timing inside the semiconductor device. Therefore, even if the current mirror circuit is not used, a timing error does not occur when the signal is captured. . Therefore, as shown in the figure, the signal input circuit 35 can be constituted by the input signal latch circuit 636 and the buffer circuit 637 without using the current mirror circuit. Of course, the dummy input circuit 625 is also composed of an equivalent dummy latch circuit 626 and dummy buffer circuit 627. Thereby, power consumption can be reduced.

FIG. 81 is a diagram showing an arrangement example of a clock distribution circuit 640, a clock generation circuit 610, a dummy input circuit (DSC) 625, and a plurality of signal input circuits in the sixteenth embodiment.
As shown in the figure, since a plurality of signals Sig-1, Sig-2,..., Sig-n are input to this semiconductor device, signal input circuits (SC-1, SC-2,. , SC-n) 35-1, 35-2,..., 35-n are provided. The clock distribution circuit 640 distributes the internal clock from the clock generation circuit 610 in the semiconductor device via the buffer circuits (CB1, CB21,..., CB34) 641 to 647, but via the wiring length to the distribution destination. The equidistant wiring is the same in the number of buffer circuits. Accordingly, in FIG. 81, the signal input circuits 635-1, 635-2,..., 635-n and the internal clock input to the dummy input circuit 625 are all in phase. Accordingly, if the dummy input circuit 625 determines the progress of the phase of the internal clock relative to the external clock CLK, and adjusts the delay amount in the clock generation circuit 610 based on the determination result, all the signal input circuits 635-1, 635-2, 635-n, the input signals Sig-1, Sig-2, ..., Sig-n can be captured at an appropriate timing.

  FIG. 82 is a diagram showing the configuration of the clock generation circuit and signal input circuit of the semiconductor device of the seventeenth embodiment, and FIG. 83 is a time chart showing the operation of the seventeenth embodiment. The clock generation circuit 610, the dummy input circuit 620, and the input circuit 630 are the same as those in the fifteenth embodiment. The difference from the fifteenth embodiment is that a PLL circuit 680 is provided. In the first embodiment, the input signal is valid for a predetermined period before and after the rising edge of the external clock. However, the input signal may be valid for a predetermined period around the phase shifted from the rising or falling edge of the external clock. is there. As shown in FIG. 83, in the seventeenth embodiment, the input signal is switched at the time when the intermediate CLK between the rising edge and the falling edge of the external clock CLK is “L” and the rising edge of the CLK whose CLK is “H”. It is shown as being captured at the midpoint of the fall. In order to determine the timing in the dummy input circuit, it is necessary to input a signal that changes at a time just between the rise and fall of the CLK having the same phase as the input signal to the dummy input circuit. Although it is conceivable to generate such a signal by delaying the external clock CLK, in that case, an error in a circuit for delaying CLK becomes a problem, and accurate determination cannot be performed. Therefore, as shown in FIG. 82, a signal DCLKa delayed from the external clock CLK by a quarter cycle of the clock is generated and input to the dummy input circuit. It is also possible to use a DLL (Deley Locked Loop) circuit instead of the PLL circuit.

  As described above, according to the present invention, even if there is a phase shift between the received clock and the input signal due to a difference in the transmission time of the signal path, it is captured in a state in which the phase shift is eliminated. The input confirmation time can be set to the minimum necessary length from the circuit operation. In addition, since the signals that are fetched and output are resynchronized, there is no phase shift and no operation occurs.

It is a figure which shows the structural example of a semiconductor device system. 1 is a diagram illustrating a basic configuration of a signal transmission system synchronized with a clock. FIG. It is a figure which shows the structure of clock synchronous transmission in a semiconductor device system. It is a figure which shows the prior art example of the input circuit of a semiconductor device. It is a figure which shows the example of the relative relationship of the clock and another signal in a semiconductor device system. It is a figure which shows the effective period resulting from the relative relationship of the clock and another signal in a semiconductor device system. It is a figure explaining the problem in the conventional semiconductor device system. It is a principle block diagram of this invention. It is a figure explaining the principle of the phase determination in the input signal acquisition in this invention. It is a figure which shows the basic composition of the semiconductor device system of the 1st aspect of this invention. It is a figure which shows the basic composition on the receiving side in a 1st aspect. It is a figure which shows the basic operation | movement in a 1st aspect. It is a figure which shows the basic composition of the receiving side semiconductor device of the 2nd aspect of this invention. It is a figure which shows the basic composition of the receiving side semiconductor device of the 3rd aspect of this invention. It is a figure which shows the structure of the clock generation circuit and output timing adjustment part of the drive side semiconductor device of 1st Example of this invention. It is a figure which shows the basic composition of the shift clock generation circuit of 1st Example. It is a figure which shows the structure of the shift clock generation circuit of 1st Example. It is a figure which shows the structure of the clock generation circuit and input circuit of the receiving side semiconductor device of 1st Example. It is a figure which shows the structural example of the delay circuit of the receiving side semiconductor device of 1st Example, and a delay control circuit. It is a figure which shows the structural example of a latch circuit. It is a time chart for demonstrating operation | movement of 1st Example. It is a figure which shows the structure of the input part of the receiving side semiconductor device of 2nd Example. It is a figure which shows the structure of the clock generation circuit of 2nd Example. It is a figure which shows the structure of the input circuit of 2nd Example. It is a figure which shows the structure of a phase determination circuit. It is a figure explaining the phase determination operation | movement in 2nd Example. It is a figure explaining the phase determination operation | movement in 2nd Example. It is a figure explaining the phase determination operation | movement in 2nd Example. It is a truth table of the phase determination operation | movement in 2nd Example. It is a figure which shows the structural example of the delay circuit of the receiving side semiconductor device of 2nd Example, and a delay control circuit. It is a figure which shows the structure of the clock generation circuit of 3rd Example. It is a figure which shows the structure of the input circuit of 3rd Example. It is a figure which shows the structure of the input circuit of 4th Example. It is a figure which shows the operation mode of 4th Example. It is a figure which shows the difference of the optimal timing by the pattern of an input signal. It is a figure which shows the structure of the input circuit of 5th Example. It is a figure explaining the phase determination operation | movement of 5th Example. It is a figure which shows the structure of the phase determination circuit of 5th Example. It is a figure which shows the truth table of the phase determination circuit of 5th Example. It is a figure which shows the structure of the input circuit of 6th Example. It is a figure which shows the structure of the timing correction circuit of 6th Example. It is a figure which shows the structure of the phase determination circuit of 6th Example. It is a figure which shows the truth table of the phase determination circuit of 6th Example. It is a figure explaining the problem of the input circuit of this invention of FIG. It is a figure which shows the change of the signal value within 1 clock cycle of the output of the input circuit of this invention of FIG. It is a figure which shows the basic composition of 7th Example of this invention. It is a figure which shows the structure of the receiving side semiconductor device of 7th Example of this invention. It is a figure which shows the structural example of the delay control circuit of 7th Example. It is a figure which shows the structure of the delay circuit and latch pulse generation circuit of 7th Example. It is a figure explaining operation | movement of the delay control circuit of 7th Example. It is a figure explaining the principle of the input timing adjustment in 7th Example. It is a figure which shows the operation | movement of the input timing adjustment in 7th Example. It is a figure which shows the whole structure of the semiconductor device of 7th Example. It is a figure which shows switching of the operation mode in 7th Example. It is a figure which shows the modification which provided the signal terminal which instruct | indicates timing adjustment. It is a figure which shows switching of the operation mode in a modification. It is a figure which shows the structure of the receiving side semiconductor device of 8th Example of this invention. It is a figure which shows the basic composition of the receiving side semiconductor device of 9th Example of this invention. It is a figure which shows the structure of the receiving side semiconductor device of 9th Example of this invention. It is a figure which shows the operation | movement of the input timing adjustment in 9th Example. It is a figure which shows the structure of the receiving side semiconductor device of 10th Example of this invention. It is a figure which shows the structure of the timing adjustment delay circuit in 10th Example of this invention. It is a figure which shows the operation | movement of the input timing adjustment in 10th Example. It is a figure explaining the problem in case a skew is 1 clock cycle or more. It is a figure which shows the structure of the receiving side semiconductor device of 11th Example of this invention. It is a figure which shows the operation | movement of the input timing adjustment in 11th Example. It is a figure which shows the operation | movement of the input timing adjustment in 11th Example. It is a figure which shows the input signal in 12th Example of this invention. It is a figure which shows the structure of the receiving side semiconductor device of 12th Example of this invention. It is a figure which shows the operation | movement of the input timing adjustment in 12th Example. It is a figure which shows the operation | movement of the input timing adjustment in 12th Example. It is a figure which shows the structure of the receiving side semiconductor device of 13th Example of this invention. It is a figure which shows the structure of the receiving side semiconductor device of 14th Example of this invention. It is a figure which shows the structure of the input circuit of 14th Example. It is a figure which shows the operation | movement of the input timing adjustment in 14th Example. It is a figure which shows the structure of the input part of the semiconductor device of 15th Example of this invention. It is a time chart which shows operation | movement of 15th Example. It is a time chart for demonstrating operation | movement of 15th Example. It is a time chart for demonstrating operation | movement of 15th Example. It is a figure which shows the structure of the input part of the semiconductor device of 16th Example. It is a figure which shows the structure of the clock distribution circuit of 16th Example, and arrangement | positioning of a clock generation circuit, a signal input circuit, and a dummy input circuit. It is a figure which shows the structure of 17th Example of this invention. It is a figure which shows operation | movement of 17th Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Clock generation circuit 11 Clock current mirror circuit 12 Clock buffer circuit 13 Delay circuit 14 Delay control circuit 20 Dummy input circuit 21 Dummy current mirror circuit 22 Dummy buffer circuit 23 Dummy latch circuit 30 Signal input circuit 31 Current mirror circuit 32 Buffer circuit 33 Latch circuit 40 Clock distribution circuit

Claims (9)

A clock generation circuit for generating an internal clock based on the received clock;
An input buffer circuit for receiving an input signal input from the outside;
In a semiconductor device comprising: an input circuit that captures and outputs an input signal in synchronization with the internal clock supplied from the clock generation circuit;
The input circuit is
A delay circuit capable of delaying an output of the input buffer circuit and selecting a delay amount;
An input circuit for capturing the output of the input buffer circuit in synchronization with the internal clock;
A phase determination circuit for determining a phase of the output of the input buffer circuit with respect to the internal clock by determining an output signal value of the input circuit;
A semiconductor device comprising: a delay control circuit that controls a delay amount of the delay circuit so that an output of the input buffer circuit is in a predetermined phase with respect to the internal clock based on a determination result of the phase determination circuit. The semiconductor device according to claim 1,
A mode register / decoder for recognizing a mode instruction signal input from the outside instructing the input signal reception timing adjustment mode,
The delay control circuit changes the delay amount based on the determination result of the phase determination circuit during the reception timing adjustment mode, and the delay control circuit holds the delay amount at other times. The semiconductor device according to claim 2,
A 1/2 divider circuit for dividing the output of the input buffer circuit by 1/2;
A switching circuit for switching a signal input to the delay circuit between an output of the input buffer circuit and an output of the ½ divider circuit;
During the reception timing adjustment mode, an input signal of a predetermined pattern is input,
In the initial stage of the reception timing adjustment mode, the semiconductor is switched so that the output of the 1/2 frequency divider circuit is input to the delay circuit, and then the output of the input buffer circuit is switched to be input to the delay circuit. apparatus. A clock generation circuit for generating an internal clock based on an external clock input from the outside;
In a semiconductor device comprising: a signal input circuit that receives an input signal input from the outside in synchronization with the external clock and takes the input signal into the semiconductor device in synchronization with an internal clock generated by the clock generation circuit ,
A signal synchronized with the input signal having the same frequency as the external clock is input, and an output signal value is determined when the input signal is captured in synchronization with the internal clock generated by the clock generation circuit. A dummy input circuit for determining whether the input timing of the input signal of the signal input circuit is advanced or delayed with respect to the internal clock,
The clock generation circuit includes:
A delay circuit that selectively delays the input external clock to generate the internal clock based on the determination result of the dummy input circuit;
A semiconductor device comprising: a delay control circuit that controls a delay amount in the delay circuit based on a determination result of the dummy input circuit. The semiconductor device according to claim 4,
The input signal is a signal that is valid for a predetermined period before and after the rising or falling of the external clock,
A semiconductor device in which the external clock is input to the dummy input circuit. The semiconductor device according to claim 4,
The effective period of the input signal is a signal shifted by a predetermined phase with respect to the rising or falling edge of the external clock,
A phase shift clock generation circuit that generates signals having different phases from the input external clock in the same cycle as the external clock,
A semiconductor device in which a clock synchronized with the input signal output from the phase shift clock generation circuit is input to the dummy input circuit. A semiconductor device according to any one of claims 4 to 6,
A semiconductor device in which a signal path for transmitting the internal clock from the clock generation circuit to the signal input circuit and the dummy input circuit has the same delay amount. The semiconductor device according to claim 7,
A semiconductor device in which a signal path for transmitting the internal clock from the clock generation circuit to the signal input circuit and the dummy input circuit is equidistant wiring. A semiconductor device according to any one of claims 4 to 8,
The signal input circuit and the dummy input circuit are a latch type semiconductor device having a latch circuit to which the input signal is directly input.

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