KR20030035417A - System using two DC reference signals for accomplishing differential signal mode - Google Patents

Abstract

PURPOSE: A system realizing differential signal manner using two DC reference signals is provided to be capable of receiving data in a differential signal manner using two DC reference signals. CONSTITUTION: A transmission part(310) transmits input data via signal lines(311-335), and a receiver part(350) receives the input data via the signal lines. The receiver part(350) compares the input data with the first reference signal(VREF1) and the second reference signal(VREF2), amplifies a comparison result and detects the input data. The first reference signal and the second reference signal have a DC voltage level. At least one of the transmission part and the receiver part has a reference signal generating part(311/351) for generating the first reference signal and the second reference signal.

Description

System using two DC reference signals for accomplishing differential signal mode}

The present invention relates to a signal transmission and reception system, and more particularly, to a system implementing a differential signaling method using two DC reference signals.

One method for transmitting and receiving data at high speed between semiconductor devices is to transmit and receive data differentially. This method has a disadvantage in that the number of data lines or data input / output pins for transmitting and receiving data is increased.

Figure 1a is a block diagram showing a signal transmission and reception system using a conventional single reference signal method. FIG. 1B is a timing diagram illustrating the signal level of FIG. 1A.

1A and 1B, the transmitter 110 of the signal transmission / reception system 100 receives a reference signal VREF and N pieces of data DATA1 to DATAN through signal lines 121, 123, 125, and 127. Send to the receiver 130. The receiver 130 detects the received data by comparing the reference signal VREF with each of the N pieces of data DATA 1 to DATAN.

However, the signal transmission / reception system 100 using a single-ended signal mode is sensitive to noise and thus difficult to transmit data at high speed. In addition, the faster the data transmission rate, the smaller the size of the data due to the attenuation effect of the signal line, so that the difference between the reference signal and the data is smaller, which makes it difficult to accurately detect the received data.

2A is a block diagram of a signal transmission and reception system using a conventional differential signaling method. FIG. 2B is a timing diagram illustrating the signal level of FIG. 2A. Referring to FIGS. 2A and 2B, the transmitter 210 of the signal transmission / reception system 200 using the differential signaling scheme uses 2N data DATA1, / DATA1,... Through the signal lines 221, 223, 225, and 227. .., DATA N, / DATA N) is transmitted to the receiver 230. The data DATA i and data DATA i are complementary data. The receiver 230 detects the received data by comparing the data DATA i with the complementary data / DATA i.

The voltage difference SW2 between the data DATA i and the complementary data / DATA i in the signal transmission / reception system 200 using the differential signaling method is the voltage of the signal transmission / reception system 100 using the single reference signal method. Since it may be equal to the difference SW1, the swing width of the data DATA i is reduced and power consumption is reduced, so that data can be received at high speed. However, there is a problem in that there should be about N data lines more than the signal transmission and reception system 100 using a single reference signal method.

Accordingly, an object of the present invention is to provide a signal transmission / reception system capable of receiving data in a differential signaling manner using two DC reference signals.

In order to more fully understand the drawings used in the detailed description of the invention, a brief description of each drawing is provided.

Figure 1a is a block diagram showing a signal transmission and reception system using a conventional single reference signal method.

FIG. 1B is a timing diagram illustrating the signal level of FIG. 1A.

2A is a block diagram of a signal transmission and reception system using a conventional differential signaling method.

FIG. 2B is a timing diagram illustrating the signal level of FIG. 2A.

3 is a diagram illustrating a signal transmission and reception system according to a first embodiment of the present invention.

4 is a timing diagram illustrating the signal level of FIG. 3.

5 is a view illustrating in detail the receiver of FIG. 3.

FIG. 6 is a circuit diagram specifically illustrating the amplifier circuit of FIG. 5.

7 is a diagram illustrating a signal transmission and reception system according to a second embodiment of the present invention.

8 is a diagram illustrating a signal transmission and reception system according to a third embodiment of the present invention.

In order to achieve the above technical problem, the signal transmission / reception system of the present invention includes a transmitter for transmitting input data through a signal line, and a receiver for receiving the input data through the signal line, wherein the receiver comprises a first reference signal and a first reference signal. And comparing each of the two reference signals with the input data, amplifying the comparison result to detect the input data, and wherein the voltage levels of the first reference signal and the second reference signal are DC voltage levels.

According to a preferred embodiment, the receiver compares each of the first reference signal and the second reference signal with the input data and outputs differential signals corresponding to the comparison result, and amplifies the difference between the differential signals. And a voltage sensing circuit for detecting the input data.

According to a preferred embodiment, at least one of the transmitter, the signal line, and the receiver includes a reference signal generator for generating the first reference signal and the second reference signal, and the reference signal generator generates the first reference signal. And a voltage generator and a resistor for dropping the signal level of the first reference signal to generate the second reference signal.

According to a preferred embodiment, at least one of the transmitter, the signal line, and the receiver includes a reference signal generator for generating the first reference signal and the second reference signal, and the reference signal generator includes a first resistor connected to a termination voltage. And a second resistor connected in series with the second resistor and connected to a ground voltage, wherein the termination voltage is the first reference signal, and the signal level of the first reference signal is dropped by the first resistor. The signal is the second reference signal.

According to a preferred embodiment, at least one of the transmitter, the signal line, and the receiver includes a reference signal generator for generating the first reference signal and the second reference signal, and the reference signal generator includes a first resistor connected to a power supply voltage. And a second resistor connected in series with the second resistor and connected to a ground voltage, wherein the power supply voltage is the first reference signal, and the signal level of the first reference signal is dropped by the first resistor. The signal is the second reference signal.

The signal transceiving system of the present invention can accurately detect the received data even when the level difference between the received signals is small, when the process, voltage or temperature is changed, and when the received data is noisy. And, since the voltage level of the reference signal is a DC voltage level, power consumption can be reduced.

In order to fully understand the present invention, the operational advantages of the present invention, and the objects achieved by the practice of the present invention, reference should be made to the accompanying drawings which illustrate preferred embodiments of the present invention and the contents described in the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Like reference numerals in the drawings denote like elements.

3 is a diagram illustrating a signal transmission and reception system according to a first embodiment of the present invention. Referring to FIG. 3, the signal transmission / reception system 300 of the present invention includes a transmitter 310, signal lines 331, 333, 335, 337, and 339, and a receiver 350. Each of the transmitter 310, the reference signal lines 337 and 339, and the receiver 350 connects the first reference signal generator 311, the second reference signal generator 341, and the third reference signal generator 351. Include. The voltage levels of the first and second reference signals VREF1 and VREF2 are DC voltage levels.

The signal transmission / reception system 300 of FIG. 3 includes three reference signal generators, but according to the present invention, fewer than three may be possible and only one may be possible. For example, only the transmitter 310 may include the reference signal generator 311.

The first reference signal generator 311 includes a first voltage generator 313, a first resistor R1, a second resistor R2, and a third resistor R3. One end of the series connected resistors R1, R2, and R3 is connected to the first voltage generator 313, and the other end of the resistors R1, R2, and R3 is connected to the ground voltage VSS.

The first resistor R1 drops the output signal level of the first voltage generator 313 to generate the first reference signal VREF1. The second resistor R2 drops the level of the first reference signal VREF1 to generate the second reference signal VREF2. In FIG. 3, each of the first and second resistors R1 and R2 generates the first reference signal VREF1 and the second reference signal VREF2, but the first voltage generator 313 is configured to generate the first resistor. Instead of R1, the first reference signal VREF1 may be generated. That is, the first resistor R1 of the components of the reference signal generator 311 may be deleted. Then, the second resistor R2 generates the second reference signal VREF2.

Since the configuration and operation of the second reference signal generator and the third reference signal generators 341 and 351 are the same as those of the first reference signal generator 311, a detailed description thereof will be omitted. That is, the output signal of each of the second voltage generator and the third voltage generators 343 and 352 is the same as the output signal of the first voltage generator 313.

The transmitter 310 of the signal transmission / reception system 300 of the present invention receives the reference signals VREF1 and VREF2 and N data DATA1 to DATAN through the signal lines 331, 333, 335, 337, and 339. Send to 350. The receiver 350 detects the received data by comparing the reference signals VREF1 and VREF2 with each of the N pieces of data DATA 1 to DATAN.

4 is a timing diagram illustrating the signal level of FIG. 3. Referring to FIG. 4, a relatively larger signal is detected from the comparison result by comparing each of the first reference signal and the second reference signal VREF1 and VREF2 with data DATA i, and the detected signal is data. Is restored as (DATA i).

5 is a view illustrating in detail the receiver of FIG. 3. Although only data DATA1 is illustrated in FIG. 5, the embodiment illustrated in FIG. 5 may be equally applied to the remaining data. Referring to FIG. 5, the receiver 350 includes a first amplifier circuit 353, a second amplifier circuit 355, and a voltage sensing circuit 357.

The first amplifier circuit 353 compares the first reference signal VREF1 applied through the reference signal line 337 with the data DATA1 transmitted through the signal line 331, and according to the comparison result, the first differential signal. V1P and the second differential signal V1N are output to the voltage sensing circuit 357. Preferably, the first differential signal V1P and the second differential signal V1N are complementary signals or differential signals.

For example, when the signal level of the first reference signal VREF1 is relatively higher than the signal level of the data DATA 1, the first amplifier circuit 353 may include the second differential signal V1N and the second differential signal V1N. Each of the first differential signals V1P having a relatively lower signal level is output to the voltage sensing circuit 357.

If the level of the first reference signal VREF1 is relatively lower than the signal level of the data DATA1, the first amplifying circuit 353 may be relative to the second differential signal V1N and the second differential signal V1N. The first differential signal V1P having a high signal level is output to the voltage sensing circuit 357, respectively.

When the level of the first reference signal VREF1 and the signal level of the data DATA1 are the same, the first amplifier circuit 353 may have the first differential signal V1P and the second differential signal V1N having the same signal level. Outputs

The second amplifying circuit 355 compares the second reference signal VREF2 applied through the reference signal line 339 with the data DATA1 transmitted through the signal line 331, and compares the third differential signal (3) according to the comparison result. V2P) and the fourth differential signal V2N are respectively output to the voltage sensing circuit 357. Preferably, the third differential signal and the fourth differential signal V2P and V2N are signals complementary to each other or differential signals.

For example, when the level of the second reference signal VREF2 is relatively higher than the signal level of the data DATA1, the second amplifying circuit 355 may be relative to the fourth differential signal V2N and the fourth differential signal V2N. The third differential signal V2P having a low signal level is output to the voltage sensing circuit 357, respectively.

If the level of the second reference signal VREF2 is relatively lower than the signal level of the data DATA1, the second amplifying circuit 355 may be more relative than the fourth differential signal V2N and the fourth differential signal V2N. As a result, the third differential signal V2P having a high signal level is output to the voltage sensing circuit 357.

When the signal level of the second reference signal VREF2 and the signal level of the data DATA1 are the same, the second amplifier circuit 355 may use the third differential signal V2P and the fourth differential signal V2N having the same signal level. )

When the signal level difference between the data DATA1 and the second reference signal VREF2 is greater than the signal level difference between the data DATA1 and the first reference signal VREF1, the operation of the second amplifying circuit 355 may be performed. It is more dominant than the operation of the amplifier circuit 353. Accordingly, the second amplifier circuit 355 detects the difference between the second reference signal VREF2 and the data DATA1 to output the third differential signal and the fourth differential signal V2P and V2N, and the voltage sensing circuit 357. ) Outputs an output signal Q and an inverted signal QB of the output signal Q in response to the third and fourth differential signals V2P and V2N.

When the signal level difference between the data DATA1 and the first reference signal VREF1 is greater than the signal level difference between the data DATA1 and the second reference signal VREF1, the operation of the first amplifying circuit 353 is performed in a second manner. The operation of the amplifier circuit 355 is more dominant. Accordingly, the first amplifier 353 detects the difference between the first reference signal VREF1 and the data DATA1 to output the first differential signal and the second differential signals V1P and V1N, and the voltage sensing circuit 357. ) Outputs an output signal Q and an inverted signal QB of the output signal Q in response to the first differential signal and the second differential signals V1P and V1N.

Preferably, the first reference signal VREF1 and the second reference signal VREF2 are complementary signals or differential signals, and the data DATA1 is a single-ended signal.

The voltage sensing circuit 357 senses and amplifies the output signals V1P, V1N, V2P, and V2N of the first amplifier circuit and the second amplifier circuits 353 and 355 to output the output signal Q and the inverted output signal QB. )

FIG. 6 shows a circuit diagram of the first and second amplifier circuits of FIG. 5. Referring to FIG. 6, the first amplifier circuit and the second amplifier circuits 353 and 355 include two load transistors MP1 and MP2, two gating transistors MN1 and MN2, and a current source MN3. .

7 is a diagram illustrating a signal transmission and reception system according to a second embodiment of the present invention. Referring to FIG. 7, the signal transmission / reception system 700 of the present invention includes a transmitter 710, signal lines 721, 723, 725, 727, 729, 731, and a receiver 750. Each of the transmitter 710, the reference signal lines 729 and 731, and the receiver 750 connects the first reference signal generator 711, the second reference signal generator 733, and the third reference signal generator 751. Include. The signal transmission / reception system 700 of FIG. 7 includes three reference signal generators 711, 733, 751, but according to the present invention, fewer than three are possible, and only one is possible. For example, only the transmitter 710 may include the reference signal generator 711.

The first reference signal generator 711 includes a first resistor R1, a second resistor R2, and a third resistor R3. One end of the series connected resistors R1, R2, and R3 is connected to the termination voltage VT, and the other end of the resistors R1, R2, and R3 is connected to the ground voltage VSS. The termination voltage VT is a voltage applied through the resistor to the signal line in order to reduce reflected waves due to impedance mismatch of signals transmitted through the signal lines.

The first resistor R1 drops the voltage level of the termination voltage VT to generate the first reference signal VREF1. The second resistor R2 drops the signal level of the first reference signal VREF1 to generate the second reference signal VREF2. In FIG. 7, each of the first and second resistors R1 and R2 generates the first reference signal VREF1 and the second reference signal VREF2, but the termination voltage VT is represented by the first reference signal ( VREF1). That is, the first resistor R1 of the components of the reference signal generator 711 may be deleted. Then, the second resistor R2 generates the second reference signal VREF2.

Since the configurations and operations of the second reference signal generator and the third reference signal generators 733 and 751 are the same as those of the first reference signal generator 711, the description thereof is omitted.

The transmitter 710 of the signal transmission / reception system 700 of the present invention uses the signal lines 721, 723, 725, 727, 729, and 731 to the reference signals VREF1 and VREF2 and N data DATA1 to DATAN. To transmit to the receiving unit 750.

The receiver 750 compares the reference signals VREF1 and VREF2 with each of the N pieces of data DATA 1 to DATAN and detects the received data. Since the configuration of the receiver 750 is the same as the embodiment shown in FIG. 5, the description thereof is omitted. The voltage level of each of the reference signals VREF1 and VREF2 is a DC voltage level.

8 is a diagram illustrating a signal transmission and reception system according to a third embodiment of the present invention. Referring to FIG. 8, the signal transmission / reception system 800 of the present invention includes a transmitter 810, signal lines 821, 823, 825, 827, 829, 831, and a receiver 850. Each of the transmitter 810, the reference signal lines 827, 829, 831, and the receiver 850 includes a first reference signal generator 811, a second reference signal generator 833, and a third reference signal generator 851. ). The signal transmission / reception system 800 of FIG. 8 includes three reference signal generators, but according to the present invention, fewer than three may be possible, and only one may be possible. For example, only the transmitter 810 may include the reference signal generator 811.

The first reference signal generator 811 includes a first resistor R1, a second resistor R2, and a third resistor R3. One end of the series connected resistors R1, R2, and R3 is connected to the power supply voltage VDD, and the other end of the resistors R1, R2, and R3 is connected to the ground voltage VSS.

The first resistor R1 drops the voltage level of the power supply voltage VDD to generate the first reference signal VREF1. The second resistor R2 drops the signal level of the first reference signal VREF1 to generate the second reference signal VREF2. In FIG. 8, each of the first and second resistors R1 and R2 generates the first reference signal VREF1 and the second reference signal VREF2, but the power supply voltage VDD is the first reference signal ( VREF1). That is, the first resistor R1 of the components of the reference signal generator 711 may be deleted. Then, the second resistor R2 generates the second reference signal VREF2.

Since the configurations and operations of the second reference signal generator and the third reference signal generators 833 and 851 are the same as those of the first reference signal generator 811, detailed description thereof will be omitted.

The transmitter 810 of the signal transmission / reception system 800 of the present invention uses the signal lines 821, 823, 825, 827, 829, and 831 to receive the reference signals VREF1 and VREF2 and N data DATA1 to DATAN. To transmit to the receiving unit 850.

The receiver 850 compares the reference signals VREF1 and VREF2 with each of the N pieces of data DATA 1 to DATAN and detects the received data. Since the configuration of the receiver 850 is the same as the embodiment shown in FIG. 5, the description thereof is omitted. The voltage level of each of the reference signals VREF1 and VREF2 is a DC voltage level.

Since the signal transmission / reception system according to the present invention can obtain the effect of detecting data in a differential signal method using one data line, the data can be detected stably and at high speed.

For example, in case of receiving 16 data at the same time at high speed, the signal transmission / reception system of the differential signaling method requires 32 signal lines, but the signal transmission / reception system according to the present invention uses two reference signal lines and 16 data lines. There is an advantage that can obtain the same effect as the signal transmission and reception system of.

In addition, the power consumption of the signal transmission and reception system of the present invention is reduced, the overall layout area of the signal transmission and reception system is reduced.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

As described above, the signal transmission and reception system according to the present invention can accurately detect the received data even when the level difference between the received signals is small, when the process, voltage or temperature is changed, and when the received data is noisy. And, since the voltage level of the reference signal is a DC voltage level, power consumption can be reduced.

Claims (8)

A transmitter for transmitting input data through a signal line; And A receiver which receives the input data through the signal line, The receiving unit compares each of the first reference signal and the second reference signal with the input data, amplifies the comparison result to detect the input data, and a voltage level of the first reference signal and the second reference signal is DC. Signal transmission and reception system, characterized in that the voltage level. The method of claim 1, wherein the receiving unit An amplifier circuit comparing each of the first reference signal and the second reference signal with the input data and outputting differential signals corresponding to the comparison result; And And a voltage sensing circuit configured to detect the input data by amplifying the difference between the differential signals. The method of claim 2, At least one of the transmitter, the signal line, and the receiver includes a reference signal generator for generating the first reference signal and the second reference signal, The reference signal generator is A voltage generator generating the first reference signal; And And a resistor for lowering the level of the first reference signal to generate the second reference signal. The method of claim 2, At least one of the transmitter, the signal line, and the receiver includes a reference signal generator for generating the first reference signal and the second reference signal, The reference signal generator is Voltage generator; A first resistor generating the first reference signal by lowering an output signal level of the voltage generator; And And a second resistor for lowering the signal level of the first reference signal to generate the second reference signal. The method of claim 2, At least one of the transmitter, the signal line, and the receiver includes a reference signal generator for generating the first reference signal and the second reference signal, The reference signal generator is A first resistor coupled to the termination voltage; And A second resistor connected in series with the second resistor and connected to a ground voltage; And the terminal voltage is the first reference signal, and the signal of which the signal level of the first reference signal is lowered by the first resistor is the second reference signal. The method of claim 2, At least one of the transmitter, the signal line, and the receiver includes a reference signal generator for generating the first reference signal and the second reference signal, The reference signal generator is A first resistor coupled to the termination voltage; A second resistor connected in series with the second resistor; And A third resistor connected in series with the second resistor and connected to a ground voltage; The signal in which the voltage level of the termination voltage drops by the first resistor is a first reference signal, and the signal in which the signal level of the first reference signal is dropped by the second resistor is the second reference signal. A signal transmission and reception system. The method of claim 2, At least one of the transmitter, the signal line, and the receiver includes a reference signal generator for generating the first reference signal and the second reference signal, The reference signal generator is A first resistor coupled to the power supply voltage; And A second resistor connected in series with the second resistor and connected to a ground voltage; And the power supply voltage is the first reference signal, and the signal of which the signal level of the first reference signal is lowered by the first resistor is the second reference signal. The method of claim 2, At least one of the transmitter, the signal line, and the receiver includes a reference signal generator for generating the first reference signal and the second reference signal, The reference signal generator is A first resistor coupled to the power supply voltage; A second resistor connected in series with the second resistor; And A third resistor connected in series with the second resistor and connected to a ground voltage; The signal in which the voltage level of the power supply voltage is lowered by the first resistor is a first reference signal, and the signal in which the signal level of the first reference signal is lowered by the second resistor is the second reference signal. A signal transmission and reception system.