JP3965877B2 - Oscillator and oscillator communication method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an oscillator and an oscillator communication method.
[0002]
[Prior art]
Conventionally, in an oscillator 1 capable of rewriting internal data, as shown in FIG. 6, in addition to a power supply terminal VDD, a ground terminal GND, and an output terminal FOUT, a CE (chip enable) terminal and a CLK (clock) are used for communication. Some have a terminal and a DATA (data) terminal.
In the oscillator 1, as shown in the timing chart of FIG. 7, access restriction is canceled while the CE terminal is maintained at a predetermined potential, and input from the DATA terminal is performed in synchronization with an external clock input from the CLK terminal. By detecting a data signal (a signal including a write address and write data), the write data transmitted from the outside can be received (at the time of writing shown in FIG. 7).
The oscillator 1 also transmits read data at a timing synchronized with an external clock input from the CLK terminal when transmitting read data (at the time of reading shown in FIG. 7).
[0003]
[Problems to be solved by the invention]
By the way, in an oscillator having this kind of communication function, as shown in FIG. 8, in order to reduce the number of communication lines inside the oscillator, a CLK terminal, a DATA terminal, and an output terminal FOUT are connected to one terminal (hereinafter referred to as “X Terminals are commonly used, and at the time of communication (when access restriction is released), the X terminal is used to transmit and receive both an external clock and a data signal.
In this case, in the state where the access restriction is released by the CE terminal, the oscillator inputs this signal SCD generated by adding an external clock and a data signal as shown in FIG. An external clock and a data signal are respectively detected from the signal SCD. That is, “H” and “L” of the data signal are determined based on a predetermined intermediate potential Vm. However, in this communication method, it is necessary to generate and transmit / receive a signal SCD including both an external clock and a data signal, which not only complicates the communication method but also separates and detects the external clock and the data signal. There is a problem that a circuit (decoder shown in FIG. 8) or the like is required, and the circuit configuration of the oscillator becomes complicated.
[0004]
SUMMARY OF THE INVENTION An object of the present invention is to provide an oscillator and an oscillator communication method capable of reducing the number of communication lines without complicating the circuit configuration.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, in the present invention, the configuration according to claim 1 is an oscillator having a communication function, and an output terminal for outputting an oscillator and an original signal of the oscillator or a divided signal of the original signal And a storage means for writing or reading data, and a control means for performing access control of the storage means and for transmitting / receiving data to / from an external device via a communication terminal. Detects the potential of the received signal received via the communication terminal at a timing synchronized with the original oscillation signal or the frequency-divided signal, and when the signal of a predetermined pattern is detected, the storage means The access restriction is released, and the storage means is made to write or read data as received data as the subsequent detection result.
According to a second aspect of the present invention, in the oscillator according to the first aspect, when the control unit determines that the potential of the communication terminal is maintained at a predetermined level for a predetermined period based on the detection result, the memory The access restriction to the means is released, and the detection result after the determination is detected as received data.
[0006]
According to a third aspect of the present invention, in the oscillator according to the first or second aspect, the received signal is synchronized with the original signal or the divided signal output from the output terminal of the oscillator by the external device. It is characterized by being input to the communication terminal of the oscillator.
According to a fourth aspect of the present invention, in the oscillator according to any one of the first to third aspects, when the oscillator transmits data, the communication is performed by synchronizing the data with the original oscillation signal or the divided signal. It outputs from the terminal for use.
[0007]
According to a fifth aspect of the present invention, in the oscillator according to any one of the first to fourth aspects, when the control unit detects a signal having a predetermined pattern based on the detection result after releasing the access restriction, Access to the storage means is prohibited.
According to a sixth aspect of the present invention, in the oscillator according to any one of the first to fourth aspects, the control unit determines a potential of the communication terminal based on the detection result after releasing the access restriction. If it is determined that the predetermined level is maintained for a period, access to the storage means is prohibited.
[0008]
According to a seventh aspect of the present invention, in the oscillator according to any one of the first to sixth aspects, the components excluding the vibrator are configured as a one-chip IC.
According to an eighth aspect of the present invention, in the oscillator according to the seventh aspect, the one-chip IC and the vibrator are housed in one package.
[0009]
According to a ninth aspect of the present invention, there is provided a vibrator, an output terminal for outputting the original vibration signal of the vibrator or the divided signal of the original vibration signal, storage means for writing or reading data, and the storage means A control means for performing access control and transmitting / receiving data to / from an external device via a communication terminal, wherein the control means is received via the communication terminal. A step of detecting a potential of a received signal at a timing synchronized with the original oscillation signal or the frequency-divided signal, and a step of releasing access restriction to the storage means when a signal of a predetermined pattern is detected; And a step of detecting subsequent detection results as received data and causing the storage means to write or read data.
[0010]
According to a tenth aspect of the present invention, in the communication method of the oscillator according to the ninth aspect, when it is determined that the potential of the communication terminal is maintained at a predetermined level for a predetermined period based on the detection result, the storage means The access restriction is canceled, and the detection result after the determination is detected as received data.
[0011]
The configuration according to claim 11 is the oscillator communication method according to claim 9 or 10, wherein the received signal is input to the communication terminal of the oscillator in synchronization with the output signal by the external device. It is a feature.
According to a twelfth aspect of the present invention, in the oscillator communication method according to any one of the ninth to eleventh aspects, when the oscillator transmits data, the data is synchronized with the output signal from the communication terminal. It is characterized by output.
[0012]
According to a thirteenth aspect of the present invention, in the oscillator communication method according to any one of the ninth to twelfth aspects, a signal having a predetermined pattern based on the detection result is obtained after the access restriction to the storage unit is released. If detected, access to the storage means is prohibited.
According to a fourteenth aspect of the present invention, in the oscillator communication method according to any one of the ninth to twelfth aspects, after the access restriction to the storage unit is released, the potential of the communication terminal is set based on the detection result. If it is determined that the predetermined level is maintained for a predetermined period, access to the storage means is prohibited.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings as appropriate.
[0014]
(1) Embodiment FIG. 1 is a schematic configuration diagram showing an oscillator and a writer device according to an embodiment of the present invention.
As shown in FIG. 1, the oscillator 10 includes a crystal resonator 11, an I / O controller 12, a control logic circuit 13, a shift register 14, and a ROM (Read Only Memory) 15. The terminal includes four terminals, that is, a power supply terminal VDD, a ground terminal GND, an output terminal FOUT, and a communication terminal CE / DATA.
In the oscillator 10, for example, a 32 kHz original vibration signal Sf output from the output terminal FOUT is input to the I / O controller 12.
The I / O controller 12 detects the potential of the communication terminal CE / DATA at a timing synchronized with the original oscillation signal Sf, while reading, the data input from the shift register 14 at the timing synchronized with the original oscillation signal Sf. At the time of writing, the data output from the writer device 20 is output from the communication terminal CE / DATA to the shift register 14 at a timing synchronized with the original oscillation signal Sf. .
[0015]
The control logic circuit 13 inputs the detection result of the potential of the communication terminal CE / DATA detected by the I / O controller 12, controls the access to the ROM 15 based on the detection result, and Control the communication process between the two. Here, the writer device 20 is a device for writing predetermined data (such as rate adjustment data) in the ROM 15 of the oscillator 10 and reading the data written in the ROM 15, and is output from the output terminal FOUT of the oscillator 10. The original oscillation signal Sf is input and data is transmitted and received at a timing synchronized with the original oscillation signal Sf, so that synchronous communication with the oscillator 10 can be performed.
[0016]
That is, as shown in the timing chart of the oscillator 10 in FIG. 2, the oscillator 10 is connected to the communication device CE / DATA by the writer device 20 for a period corresponding to 8 pulses of the original oscillation signal Sf shown in FIG. When the level is maintained (indicated by “preamble” in FIG. 2), the access restriction is canceled and the ROM 15 is set in a standby state.
As shown in FIG. 2B, the oscillator 10 remains at the H level after the writer device 20 maintains the communication terminal CE / DATA at the H level for a period corresponding to 8 pulses of the original oscillation signal Sf. If it is maintained, data is written to the ROM 15 by communication with the writer device 20 by shifting to a write mode in which the detection result of the potential of the subsequent communication terminals CE and DATA is detected as a write address and write data. It has been made so that it can.
[0017]
On the other hand, as shown in FIG. 2C, the oscillator 10 maintains the L level after the writer device 20 maintains the communication terminal CE / DATA at the H level for a period corresponding to 8 pulses of the original oscillation signal Sf. When the level is changed, a transition is made to a read mode in which the subsequent detection result of the potential of the communication terminal CE / DATA is detected as a read address, whereby the oscillator 10 is recorded in the ROM 15. Data can be read out and transmitted to the writer device 20.
In this case, the oscillator 10 outputs the data read from the ROM 15 to the communication terminal CE / DATA at a timing synchronized with the original oscillation signal Sf, while the writer device 20 receives the data at a timing synchronized with the original oscillation signal Sf. The writer device 20 can reliably receive the data output from the oscillator 10.
Then, after canceling the access restriction, the oscillator 10 maintains the access to the ROM 15 when the communication terminal CE / DATA is maintained at the L level for a period corresponding to 25 pulses of the original oscillation signal Sf by the writer device 20. The communication process is terminated with prohibition.
[0018]
As described above, the data communication between the oscillator 10 and the writer device 20 is performed in synchronization with the original oscillation signal Sf output from the output terminal FOUT that the oscillator 10 is necessarily provided, so that the synchronous communication can be easily performed. Can do.
Further, the oscillator 10 can perform access control of the oscillator 10 and data communication between the writer device 20 with only one communication terminal CE / DATA, and the number of communication lines can be reduced to one. .
Therefore, the oscillator 10 needs to be provided with a CE terminal for performing access control independently as in the conventional oscillator (FIG. 5), and a CLK terminal for inputting a signal (external clock) for synchronization. In addition, there is no need for a circuit (decoder) for extracting a signal (external clock) for synchronization from the input signal as in the conventional oscillator (FIG. 7) with a reduced number of terminals. The number of communication lines can be reduced without complicating the circuit configuration as compared with the oscillator.
[0019]
Further, since the oscillator 10 has a simple circuit configuration and can reduce the number of terminals, it is possible to reduce the size of the package when the oscillator 10 is configured as one package. The oscillator 10 is actually a ceramic package in which a circuit excluding the crystal unit 11 is formed by a one-chip IC and is sealed with the crystal unit 11 interposed therebetween as shown in FIG. (A)) or a plastic package (FIG. 3B) in which the crystal unit 11 and the one-chip IC are molded and sealed.
[0020]
(2) Modification (2-1) First Modification In the above-described embodiment, whether or not the potential of the communication terminal CE / DATA is maintained at a predetermined level for a predetermined period in the access control of the oscillator 10 is determined. However, the present invention is not limited to this, and the access control of the oscillator may be performed according to whether or not a signal having a predetermined pattern is detected from the communication terminal CE / DATA.
[0021]
(2-2) Second Modification In the above-described embodiment, the case where the mode is shifted to the write mode or the read mode in accordance with the voltage level of the communication terminal CE / DATA after the access restriction is released has been described. The invention is not limited to this, and as shown in FIG. 4, the mode may be shifted to a desired mode according to data detected in a mode setting period (for example, a period corresponding to 4 pulses) after the access restriction is released. Good.
[0022]
(2-3) Third Modification In the above-described embodiment, the case where the present invention is applied to the oscillator that outputs the original oscillation signal Sf as it is is described. However, the present invention is not limited to this and is used for setting the division ratio. The present invention can be widely applied to frequency-divided multi-output oscillators and programmable oscillators having a plurality of terminals, voltage-controlled oscillators that can change the frequency of output signals, temperature-compensated oscillators that can compensate for the oscillation frequency, and real-time clocks.
Here, FIG. 5 is a schematic configuration diagram when the present invention is applied to a temperature compensated oscillator (TCXO). Needless to say, the oscillator is not limited to an oscillator including a crystal resonator, and may be an oscillator including another resonator such as a ceramic resonator.
[0023]
【The invention's effect】
As described above, according to the present invention, the number of communication lines can be reduced without complicating the circuit configuration of the oscillator.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an oscillator and a writer device according to an embodiment of the present invention.
FIG. 2 is a timing chart of the oscillator.
FIG. 3A is a perspective view when the oscillator is configured with a ceramic package, and FIG. 3B is a perspective view when the oscillator is configured with a plastic package.
FIG. 4 is a timing chart of an oscillator according to a second modification.
FIG. 5 is a schematic configuration diagram showing a temperature compensated oscillator according to a third modification.
FIG. 6 is a schematic configuration diagram showing a conventional oscillator capable of rewriting internal data.
FIG. 7 is a timing chart of the oscillator.
FIG. 8 is a schematic configuration diagram showing a conventional oscillator that can rewrite internal data.
FIG. 9 is a signal waveform diagram of a signal transmitted to the oscillator.
[Explanation of symbols]
1, 10 ... Oscillator,
11 …… Quartz crystal,
12 …… I / O controller,
13 …… Control logic circuit,
14: Shift register,
15 …… ROM,
20: Writer device,
Sf …… Source signal,
CE / DATA: Terminal for communication,
FOUT …… Output terminal
GND: Ground terminal,
VDD: Power supply terminal.

Claims (14)

In an oscillator having a communication function,
A vibrator, and an output terminal for outputting the original vibration signal of the vibrator or the divided signal of the original vibration signal;
Storage means for writing or reading data;
Control means for performing access control of the storage means, and for transmitting and receiving data to and from an external device via a communication terminal,
The control means detects the potential of the received signal received through the communication terminal at a timing synchronized with the original oscillation signal or the divided signal, and when a signal of a predetermined pattern is detected, An oscillator characterized in that the access restriction to the storage means is released, and the subsequent detection result is used as received data to cause the storage means to write or read data. The oscillator of claim 1, wherein
If the control means determines that the potential of the communication terminal is maintained at a predetermined level for a predetermined period based on the detection result, the control means releases the access restriction to the storage means, and the detection result after the determination An oscillator characterized by detecting as received data. The oscillator according to claim 1 or 2,
The oscillator is characterized in that the received signal is input to a communication terminal of the oscillator in synchronization with the original oscillation signal or the frequency-divided signal output from the output terminal of the oscillator by the external device. The oscillator according to any one of claims 1 to 3,
When the oscillator transmits data, the data is output from the communication terminal in synchronization with the original oscillation signal or the divided signal. The oscillator according to any one of claims 1 to 4,
The oscillator prohibits access to the storage unit when detecting a signal having a predetermined pattern based on the detection result after releasing the access restriction. The oscillator according to any one of claims 1 to 4,
If the control unit determines that the potential of the communication terminal is maintained at a predetermined level for a predetermined period based on the detection result after canceling the access restriction, the control unit prohibits access to the storage unit. Features an oscillator. The oscillator according to any one of claims 1 to 6,
The component except the vibrator is configured as a one-chip IC. The oscillator according to claim 7, wherein
The oscillator, wherein the one-chip IC and the vibrator are housed in one package. A vibrator, an output terminal for outputting the original vibration signal of the vibrator or the frequency-divided signal of the original vibration signal, storage means for writing or reading data, access control of the storage means, and communication In a communication method of an oscillator comprising a control means for transmitting and receiving data to and from an external device via a terminal,
The control means detects a potential of a received signal received via the communication terminal at a timing synchronized with the original oscillation signal or the frequency-divided signal;
Removing a restriction on access to the storage means when a signal of a predetermined pattern is detected;
And a step of detecting subsequent detection results as received data and causing the storage means to write or read data. The oscillator communication method according to claim 9, wherein
When it is determined that the potential of the communication terminal is maintained at a predetermined level for a predetermined period based on the detection result, the access restriction to the storage unit is released, and the detection result after the determination is detected as reception data. An oscillator communication method characterized by: The oscillator communication method according to claim 9 or 10,
The received signal is input to the communication terminal of the oscillator in synchronization with the output signal by the external device. The oscillator communication method according to any one of claims 9 to 11,
When the oscillator transmits data, the data is output from the communication terminal in synchronization with the output signal. The communication method for an oscillator according to any one of claims 9 to 12,
A method of communicating an oscillator, comprising: prohibiting access to the storage means when a signal having a predetermined pattern is detected based on the detection result after releasing the access restriction to the storage means. The communication method for an oscillator according to any one of claims 9 to 12,
After releasing the access restriction to the storage means, if it is determined that the potential of the communication terminal is maintained at a predetermined level for a predetermined period based on the detection result, access to the storage means is prohibited. An oscillator communication method characterized by the above.

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