JP2015076667A - Communication device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable long distance communication in an external synchronization communication.SOLUTION: In external synchronization communication using a communication clock, when communication length is long, a reception signal delays and clock synchronization cannot be done, and a serial reception signal cannot be properly converted into parallel reception data. Therefore, a communication device compares a transmission signal with the reception signal to detect the amount of delay, and generates a delay compensation clock signal by delaying a communication clock signal by the same as the amount of delay. The reception signal is converted into reception data by this.

Description

  The present invention transmits a communication clock signal and a transmission signal in serial communication between a communication device and a counterpart device, and the counterpart device receiving the communication clock signal and the transmission signal sends a signal to the communication device. It is related with the communication apparatus which transmits as a received signal of this and processes this received signal.

  In serial communication from a communication device, when a clock signal used in a parallel / serial converter is transmitted with a transmission signal, and the received signal is converted into parallel received data by the parallel / serial converter in the counterpart device It is known as a prior art that the external synchronous communication using the clock signal generated in step 1 is used for communication between devices inside the apparatus as a simple communication method.

  For example, in the clock synchronous serial interface circuit according to Patent Document 1 below, external synchronous communication is used for serial data transmission / reception between a communication device and a counterpart device existing in the same device having different transmission / reception formats.

  FIG. 3 shows an example of the configuration of a conventional communication device using external synchronization. In FIG. 3, numbers 1 and 2 are a communication device and a counterpart device, respectively, number 3 is a serial communication between the communication device and the counterpart device, and numbers 30, 31, and 32 are signals that are transmitted and received in the serial communication. A communication clock signal, a transmission signal, and a reception signal, respectively. Reference numerals 18a, 18b, and 18c are communication signal interfaces, respectively, that electrically insulate the communication device 1 from the serial communication 3 or perform level conversion. Then, the communication apparatus 1 transmits the communication clock signal 30 and the transmission signal 31 to the counterpart device 2 and simultaneously processes the reception signal 32 from the counterpart device 2.

  Further, in FIG. 3, numbers 10, 13, 14, 15, and 19 are a microprocessor, an oscillator, a reference clock, a frequency divider, and a division ratio command. The oscillator 13 generates a reference clock 14, and the microprocessor The frequency divider 15 divides the reference clock 14 by the frequency division ratio command 19 output from 10 to generate a communication clock signal 30. In FIG. 3, numbers 11 and 16 are parallel / serial converters and transmission data. The parallel transmission data 16 generated by the microprocessor 10 is transmitted in synchronization with the communication clock signal 30 in the parallel / serial converter 11. A signal 31 is generated.

  In FIG. 3, numbers 12 and 17 are a serial / parallel converter and received data, respectively, and a received signal 32 is obtained by extracting parallel received data 17 by the serial / parallel converter 12 using a communication clock signal 30 and receiving data. 17 is read by the microprocessor 10 for processing.

Japanese Patent Laid-Open No. 2007-206878

  However, since the communication method inside the apparatus is mainly used for the communication by the conventional external synchronization, when the communication distance reaches a long distance by communication between apparatuses or the like, the communication clock signal 30 generated in the communication apparatus 1 is On the other hand, the received signal 32 received by the communication apparatus 1 is delayed, and the serial / parallel converter 12 cannot accurately convert the received signal 32 into the received data 17.

  In order to solve the above problems, the present invention uses the communication clock signal 30 to generate the serial transmission signal 31 from the transmission data 16 that is a numerical value, and the serial / serial converter 11. The serial / parallel converter 12 that generates the reception data 17 that is a numerical value from the reception signal 32 is included, and the counterpart device 2, the communication clock signal 30, the transmission signal 31, and the reception signal 32 In addition to the conventional communication device that performs serial communication 3, the delay detector 24 and the clock delay 22 are included, and the delay detector 24 has a relative relationship between the received signal 32 and the transmitted signal 31. The delay amount 20 is detected by counting the reference clock 14, and the communication clock signal 30 is delayed by the delay amount 20 in the clock delay unit 22. Wherein generating a delay compensation communication clock signal 23, the communication apparatus 1, characterized in that the said delay compensation communication clock signal 23 by performing a reception processing of the received signal 32 and extracts the received data 17.

  When the received signal 32 from the counterpart device 2 is replied within a predetermined time, the delay amount 20 is averaged to obtain an average delay amount, and the communication clock signal 30 The delay compensation communication clock signal 23 is generated by performing delay compensation using an averaged delay amount, and the reception data 32 is received by the delay compensation communication clock signal 23 to extract the reception data 17. The communication device 1 that performs.

  According to the present invention, even when the communication distance is long and the received signal 32 is delayed, communication can be performed by external synchronization communication with a simple structure.

Explanatory drawing which shows the system configuration | structure of this invention. Explanatory drawing which shows the communication clock signal in the communication of this invention, a transmission signal, and a received signal waveform. Explanatory drawing which shows the system structure of a conventional system.

  The purpose of communication between devices with long communication lengths using external synchronous communication, which is a simple communication method, was realized by a simple method of delaying the clock.

  An embodiment of the present invention will be described in detail with reference to FIGS. 1 having the same reference numerals as those in FIG. 3 have the same functions, and the description thereof is omitted.

  In FIG. 1, numerals 20, 21, 22, 23, and 24 are a delay amount, a delay compensation command, a clock delay device, a delay compensation communication clock signal, and a delay amount detector, respectively. The delay amount detector 24 compares the transmission signal 31 and the reception signal 32 and counts the relative delay time with the reference clock 14 to detect the delay amount 20. Then, the microprocessor 10 reads the delay amount 20 and writes it to the clock delay unit 22 as a delay compensation command 21. Then, the clock delay unit 22 delays the communication clock signal 30 by the time according to the delay compensation command 21, and generates and outputs a delay compensation communication clock signal 23.

  2 will be described in detail with reference to FIG. 2, (a), (b), and (c) are the waveform of the reference clock 14, the waveform of the communication clock signal 30, and the contents of the transmission signal 31, respectively. The reference clock 14 in FIG. 2A is frequency-divided by the frequency divider 15 to obtain FIG. Further, as shown in FIG. 2C, the transmission signal 31 includes a header indicating the head, a transmission data, and an error check.

  2D and 2E show the contents of the received signal 32 and the waveform of the delay compensation communication clock signal 23. FIG. FIG. 2D includes a header indicating the beginning of the content of the received signal 32, received data, and error checking. FIG. 2C shows a waveform obtained by shifting the communication clock signal 30 using a delay compensation command 21 described later.

  FIGS. 2- (f) and (g) are enlarged views of the header portion of FIGS. 2- (b) and 2- (c) when the unit of transmission / reception is 8 bits. FIG. 2- (f) shows a square wave that changes periodically. FIG. 2- (g) is a serial signal having 1-bit data for each period of FIG. 2- (f).

  The contents of the header in FIG. 2- (c) and the header in FIG. 2- (d) are the same. Also, the contents of the headers in FIGS. 2C and 2D are signals that are not always Hi or not always Low.

  The delay detector 24 compares the reception signal 32 received by the communication device 1 and the transmission signal 31 transmitted by the communication device 1 with the header of the reception signal 32 and the header of the transmission signal 31, which are the same signal. 20 is detected.

  The counting of the reference clock 14 is started at the switching timing of the top signal of the header in FIG. 2- (c), and the counting of the reference clock 14 is stopped at the switching timing of the signal at the top of the header in FIG. . The numerical value at the end of the counting is set as a delay amount 20.

  The user visually sets the delay amount 20, and sets the delay amount 20 to the clock delay unit 22 as a delay compensation command 21. A clock delay unit 22 that delays the signal in synchronization with the reference clock 14 generates a delay-compensated communication clock signal 23 of the clock signal delayed for the same period as the delay amount 20.

  From the serial signal of the reception signal 32 received by the communication device 1, the serial / parallel converter 12 extracts the reception data 17 of the parallel data using the delay compensation communication clock signal 23. The received data 17 is read and processed by the microprocessor 10.

  In addition, when the communication device 1 transmits a transmission signal 31 and the reception signal 32 is replied within a predetermined time period, the microprocessor 10 performs an average value process of the delay amount 20 to obtain an average delay amount. The average delay amount is obtained and sent to the clock delay unit 22 as the delay compensation command 21.

  Since external synchronous communication is simple and high-speed communication, it is widely used for communication inside the device. However, it can be used for communication with a device having a long communication length. A large amount of data can be sent and received.

DESCRIPTION OF SYMBOLS 1 Communication apparatus 2 Counterpart apparatus 11 Parallel / serial converter 12 Serial / parallel converter 14 Reference clock 16 Transmission data 17 Reception data 20 Delay amount 22 Clock delay device 23 Delay compensation communication clock signal 24 Delay amount detector 30 Communication clock signal 31 Transmission signal 32 Reception signal

Claims (2)

Using the communication clock signal
A parallel / serial converter that generates a serial transmission signal from numerical transmission data;
A serial / parallel converter for generating reception data that is a numerical value from a serial reception signal;
A communication device that performs serial communication with a counterpart device using the communication clock signal, the transmission signal, and the reception signal,
A delay amount detector, and a clock delay unit;
The delay detector detects a relative delay amount of the reception signal with respect to the transmission signal by counting a reference clock,
The clock delay unit generates a delay compensated communication clock signal obtained by delaying the communication clock signal by the delay amount, and performs reception processing of the received signal using the delay compensated communication clock signal to extract the received data. A communication device. When the received signal from the counterpart device is replied within a predetermined time, an average processing is performed on the delay amount to obtain an average delay amount,
The delay compensation communication clock signal is generated by performing delay compensation by the average delay amount on the communication clock signal,
2. The communication apparatus according to claim 1, wherein the reception data is extracted by performing reception processing of the reception signal using the delay compensation communication clock signal.

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