JP2014075634A - Communication system, communication speed automatic detector, communication device and communication speed setting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication system that has improved convenience when communication speed is automatically detected and a communication device is added.SOLUTION: A communication system includes: a first communication device that comprises transmission means for transmitting a pattern in which all signal waveforms sequentially change covering modulation signal levels to a communication path at a cycle of an inverse of modulation speed; and a second communication device that comprises detection means for detecting communication speed sampling the pattern from the communication path at a prescribed interval.

Description

  The present invention relates to a communication system, communication speed automatic detection device, communication device, and communication speed setting method that support automatic detection of communication speed.

  In communication between communication apparatuses using the time division multiplex communication method, it is important to set parameters that match scheduling in each communication apparatus. In general, the scheduling can be adjusted according to the communication system. Therefore, the parameters differ for each communication system, and when additional communication devices are connected, it is necessary to match the parameters of the added communication device with the communication system of the connection destination. However, setting parameters including the communication protocol is difficult for anyone other than the designer of the communication system to be connected.

  Patent Document 1 discloses a method of automatically configuring parameters of an ECU (Electronic Control Unit) added to a communication network using time division multiplex communication. However, the communication speed, which is a parameter of the communication system, is not subject to automatic setting. Patent Document 2 discloses a communication speed setting method in asynchronous transmission between a terminal device and an input / output device.

JP 2008-236217 A (2nd and 7th pages, FIGS. 12 and 13) Japanese Laid-Open Patent Publication No. 1-188060 (pages 1 and 2, FIGS. 1 (a) and 1 (b))

  In the technique of Patent Document 1, it is necessary to statically set in advance the communication speed of the communication system of the addition destination in the ECU to be added. On the other hand, in the technique of Patent Document 2, specific data is transmitted from the terminal device at the time of initialization between the terminal device and the input / output device, and the specific data is sampled on the input / output device side. The input / output device is a method for determining a communication speed by comparing a pattern obtained by sampling with a predetermined pattern.

  As described above, the techniques of Patent Documents 1 and 2 cannot automatically detect the communication speed and dynamically set the communication speed. For this reason, in the techniques of Patent Documents 1 and 2, in order to add a communication device to a communication system that is already operating, the user has to manually set a predetermined setting for the communication device to be added.

  If the technique of patent document 2 is used, the communication speed of the operating communication system can be determined. However, in order to cope with variations in signal waveforms on the communication path and combinations of various communication speeds, there is a problem that all the various patterns that can accommodate varying signal waveforms must be prepared.

  An object of the present invention has been made in view of the above problems, and a communication system that automatically detects a communication speed of a communication system and improves convenience when adding a communication apparatus, and automatic communication speed detection. An apparatus, a communication apparatus, and a communication speed setting method are provided.

  The communication system according to the present invention includes a first communication device including a sending unit that sends a pattern that changes in sequence and covers all modulation signal levels to the communication path in a cycle that is a reciprocal of the modulation speed, and a pattern received from the communication path. Is sampled at a predetermined interval, and has a second communication device provided with detection means for detecting the communication speed. The communication speed automatic detection device of the present invention samples a pattern received from a device that sends out a pattern that changes sequentially covering all modulation signal levels at a reciprocal period of the modulation speed at a predetermined interval, and determines the communication speed. It has a detection means to detect.

  The communication apparatus of the present invention detects a first communication speed by sampling a first pattern that changes sequentially covering all modulation signal levels at a reciprocal period of the first modulation speed at a predetermined interval. And a second pattern received from a device that sends out a second pattern that changes in sequence and covers all modulation signal levels in a reciprocal period of the second modulation speed. Is detected at a predetermined interval to detect the second communication speed.

  In the communication speed setting method of the present invention, a pattern that covers all modulation signal levels in a reciprocal period of the modulation speed and sequentially changes is sent to the communication path, and the pattern received from the communication path is sampled at a predetermined interval. The communication speed is detected.

  According to the present invention, since the communication speed of the communication system is automatically detected, there is an effect that the convenience when adding a communication device to the communication system is high.

It is a block diagram which shows the structure of the communication system of the 1st Embodiment of this invention. It is a block diagram which shows the internal structure of the communication apparatus of the 1st Embodiment of this invention. It is explanatory drawing which compared the bit for every communication speed of the 1st Embodiment of this invention. It is a table | surface which shows the time width and sampling frequency | count of the bit for every communication speed of the 1st Embodiment of this invention. It is explanatory drawing of the data stream structure and communication speed detection pattern of the 1st Embodiment of this invention. It is a block diagram which shows the internal structure of the communication speed detection part of the 1st Embodiment of this invention. It is the state transition diagram which showed the operation | movement of the communication speed detection part of the 1st Embodiment of this invention. It is the timing chart which showed the operation | movement of the communication speed detection part of the 1st Embodiment of this invention. It is a block diagram which shows the structure of the communication system of the 2nd Embodiment of this invention. It is a block diagram which shows the internal structure of the communication apparatus of the 2nd Embodiment of this invention.

Embodiments of the present invention will be described below in detail with reference to the drawings.
(First embodiment)
A first embodiment of the present invention will be described.

  FIG. 1 is a block diagram showing a configuration of a communication system according to the first exemplary embodiment of the present invention. With reference to FIG. 1, the structure of the communication system 1 of the 1st Embodiment of this invention is demonstrated.

  The communication system 1 in FIG. 1 includes a communication path 10, communication devices A101 to 10n (n is an integer equal to or greater than 1), and a communication device B110.

  The communication devices A101 to 10n are already connected to each other via the communication path 10. The communication device B110 is a communication device newly added to the communication system 1.

  At least one of the communication devices A 101 to 10 n includes a communication speed detection pattern sending unit 11. In FIG. 1, the communication apparatus A 101 includes a communication speed detection pattern sending unit 11. The communication speed detection pattern sending unit 11 sends a preset communication speed detection pattern to the communication path 10.

  The communication device B110 includes a communication speed detection unit 12. The communication speed detection unit 12 detects a communication speed from a signal received from the communication path 10 by detecting a partial signal for performing communication speed detection including a preset communication speed detection pattern.

  With reference to FIG. 1, operation | movement of the communication system 1 of the 1st Embodiment of this invention is demonstrated. The communication speed detection pattern sending unit 11 of the communication apparatus A 101 of the communication system 1 sends a preset communication speed detection pattern to the communication path 10.

  The communication device B110 is newly added to the communication path 10. At that time, the communication speed detection unit 12 of the communication apparatus B110 takes in the signal of the communication path 10 and starts detecting a partial signal including a preset communication speed detection pattern. Then, the communication speed detection unit 12 detects a partial signal including a communication speed detection pattern, determines the communication speed of the communication system 1, and starts automatic setting of communication parameters other than the communication speed.

  FIG. 2 is a block diagram illustrating an internal configuration of the communication apparatus according to the first embodiment of this invention. With reference to FIG. 2, the configuration of the communication apparatus C120 according to the first embodiment of the present invention will be described. The internal components of the communication device A101 and the communication device B110 are common. Therefore, for convenience of explanation, the communication device A101 and the communication device B110 will be described using the communication device C120 including both the communication device A101 and the internal components of the communication device B110.

  The communication device C120 includes a communication speed detection pattern sending unit 11, a communication speed detection unit 12, a communication controller unit 21, a parameter setting unit 22, an automatic configuration unit 23, a bus driver 24A, and a bus driver 24B. Prepare. The communication device C120 is connected to the communication channel 10A duplexed as the communication path 10 and the communication channel 10B.

  Here, the communication speed detection pattern sending unit 11 and the communication speed detection unit 12 have the same functions as described with reference to FIG. 1, and the same names and the same numbers are added and description thereof is omitted.

  The communication controller 21 communicates with another communication device C120 via the communication path 10. The parameter setting unit 22 holds communication parameters for the communication device C120 to communicate with other communication devices C120 via the communication path 10. The automatic configuration unit 23 monitors a data stream of the communication path 10 and extracts a communication parameter so that the communication apparatus C120 communicates with another communication apparatus C120 via the communication path 10. The bus drivers 24A and 24B are connected to the communication channel 10A and the communication channel 10B of the communication path 10. Then, the bus drivers 24A and 24B transmit the transmission signals TxA and TxB to the communication path 10, and receive the reception signals RxA and RxB from the communication path 10.

  With reference to FIG. 2, the operation of the communication apparatus C120 according to the first embodiment of the present invention will be described.

  The communication device C120 can operate as the communication device A101. In this case, the communication device C 120 sends a predetermined communication speed detection pattern from the communication speed detection pattern sending unit 11 to the communication path 10. Further, the parameter setting unit 22 sends communication parameters to the communication path 10.

  The communication device C120 can also operate as a communication device B110 added to the communication system 1. In this case, the communication device C120 is connected to the communication path 10 and outputs the reception signals RxA25 and RxB26 from the bus drivers 24A and 24B to the communication speed detection unit 12.

  The communication speed detection unit 12 starts detecting a partial signal including a communication speed detection pattern transmitted by the communication apparatus C120 as the communication apparatus A101 from the reception signals RxA25 and RxB26. When the communication speed detection unit 12 detects a partial signal in the reception signal RxA25 or RxB26, the communication speed detection unit 12 outputs a communication speed detection signal indicating the detected communication speed to the parameter setting unit 22. The parameter setting unit 22 sets a parameter indicating the detected communication speed according to the communication speed detection signal. Then, the parameter setting unit 22 outputs a communication speed setting signal for setting the communication speed based on the set communication speed parameter to the communication controller unit 21 and the automatic configuration unit 23 to set the communication speed. .

  The automatic configuration unit 23 can receive the data streams of the reception signals RxA25 and RxB26 from the bus drivers 24A and 24B in response to the setting of the communication speed. Then, the automatic configuration unit 23 extracts communication parameters sent from the communication device A101 from the data streams of the reception signals RxA25 and RxB26, and sets the communication parameters in the communication controller unit 21 and the parameter setting unit 22.

  Therefore, the communication controller unit 21 completes the communication speed setting and communication parameter setting, and can transmit and receive data streams on the communication channels 10A and 10B via the bus drivers 24A and 24B.

  The parameter setting unit 22 holds communication parameters.

  Accordingly, the communication device C120 that operates as the communication device B110 can communicate with the communication device C120 that operates as the communication devices A101 to 10n, and the addition of the communication device B110 to the communication system 1 is completed.

  In this way, the communication device B110 detects the partial signal including the communication speed detection pattern from the communication device A101, determines the communication speed, and enables the communication parameter setting necessary for communication in the existing communication system to be automated. .

  FIG. 3 is an explanatory diagram comparing bits for each communication speed according to the first embodiment of this invention. With reference to FIG. 3, the bit sampling operation for each communication speed according to the first embodiment of the present invention will be described in comparison.

  The communication speed of the communication system 1 will be described as three types of 10 Mbps, 5 Mbps, and 2.5 Mbps. Therefore, the minimum unit time (1 gdbit) corresponding to 1-bit information is 100 ns, 200 ns, and 400 ns at each communication speed. Therefore, when the time (1 dgbit) corresponding to this 1-bit information is sampled with an 80 MHz clock signal (for sampling), the number of sampling corresponding to each communication speed is 7 times, 8 times, 9 times, 15 times. Or 16 times, 17 times, 31 times, 32 times, or 33 times. FIG. 4 shows the communication speed and the number of sampling times shown here.

  FIG. 4 is a table showing the bit time width and the number of samplings for each communication speed according to the first embodiment of this invention. FIG. 4 shows the relationship between the communication speed shown in FIG. 3, the width of time (1 dgbit) corresponding to 1-bit information, and the number of samplings. The communication speed is detected by counting the number of samplings for 1 dgbit.

  FIG. 5 is an explanatory diagram of a data stream configuration and a communication speed detection pattern according to the first embodiment of this invention. With reference to FIG. 5, detection of a communication speed detection pattern in a data stream will be described.

  The data frame 51 exemplifies a data frame of the communication system 1 of the time division multiplex communication method. The data frame 51 is a data stream communicated on the communication path 10 in a time unit called a slot.

  The data frame 51 includes a header part 52, a payload part 53, and a CRC part 54. The header part 52 is a part indicating the type of the data frame 51. The payload part 53 is a part in which the communication apparatuses A 101 to 10n become users and transmit and receive information in a time division manner. The CRC unit 54 is a part used for checking and error correction of the data frame 51.

  The payload portion 53 includes a communication speed detection pattern 55 as a part of user information at the time division timing transmitted by the communication apparatus A101. The communication speed detection pattern 55 is an 8-bit “10101010” pattern. Here, in the communication system 1, it is assumed that a BSS (Byte Start Sequence) is added before and after each 1-byte data of the user information and is transmitted to the communication path 10. The BSS is a 2-bit “10” pattern. Therefore, the communication speed is detected by counting the number of samplings for 1 dgbit shown in FIGS. That is, the communication speed is determined by detecting the partial signal 56 for detecting the communication speed including the BSS and the communication speed detection pattern 55 in the reception signals RxA25 and RxB26 from the communication path 10.

  FIG. 6 is a block diagram illustrating an internal configuration of the communication speed detection unit according to the first embodiment of this invention. With reference to FIG. 6, the configuration of the communication speed detecting unit 12 according to the first embodiment of the present invention will be described.

  The communication speed detection unit 12 in FIG. 6 corresponds to the communication speed detection unit 12 in FIG. Therefore, about the same structure, the same name and the same number are attached and description is abbreviate | omitted.

  The communication speed detection unit 12 of FIG. 6 includes a communication speed detection unit 61A, a communication speed detection unit 61B, and an upper communication unit 66. The communication speed detector 61A detects a communication speed from the received signal RxA25 and outputs a communication speed detection signal A. The communication speed detector 61B detects the communication speed from the received signal RxB26 and outputs the speed detection signal B. The host communication unit 66 receives the communication speed detection signal A of the communication speed detection unit 61A or the communication speed detection signal B of the communication speed detection unit 61B, and outputs a communication speed detection signal 67.

  The communication speed detection unit 61A includes a sampling unit 62A, an edge detection unit 63A, a counter unit 64A, and a pattern detection unit 65A.

  The sampling unit 62A samples the received signal RxA25 with the clock signal 60 and outputs a sampling signal.

  Upon receiving the sampling signal, the edge detection unit 63A receives an edge detection signal indicating a change in data, an edge type signal indicating whether the data change is rising or falling, and a counter unit 64A for each edge detection. A counter reset signal for resetting is output.

  The counter unit 64A is reset by a counter reset signal. After the reset, the counter unit 64A counts the counter clock signal 60 and outputs a counter output signal.

  The pattern detection unit 65A receives the edge detection signal, the edge type signal, and the counter output signal, detects the partial signal 56, and outputs the communication speed detection signal A.

  Since the communication speed detection unit 61B has the same configuration as the communication speed detection unit 61A, description thereof is omitted.

  The host communication unit 66 receives the communication speed detection signal A of the communication speed detection unit 61A or the communication speed detection signal B of the communication speed detection unit 61B, and outputs a communication speed detection signal 67.

  The operation of the communication speed detection unit 12 will be described with reference to FIG.

  Since the communication speed detector 61A and the communication speed detector 61B have the same configuration, the communication speed detector 61A will be described below as an example.

  The clock signal 60 is a clock pulse signal having a frequency of 80 MHz and is supplied to all blocks.

  The sampling unit 62A samples the reception signal RxA25 with the clock signal 60, and outputs the result as a sampling signal to the edge detection unit 63A.

  The edge detection unit 63A detects a change in the signal level of the sampling signal and outputs an edge detection signal to the pattern detection unit 65A. Further, the edge detection unit 63A outputs an edge type signal to the pattern detection unit 65A. The edge type signal indicates the type of edge, that is, whether the change in signal level is a falling edge that is a change from High level to Low level or a rising edge that is a change from Low level to High level. Show. Further, the edge detection unit 63A outputs a counter reset signal to the counter unit 64A at the time of edge detection.

  The counter unit 64A resets the counter value to 1 by the counter reset signal. After the reset, the counter unit 64A counts the clock signal 60. The counter unit 64A receives the counter reset signal and outputs the counter value immediately before the reset to the pattern detection unit 65A as a counter output signal. The counter value immediately before the reset is the number of times of sampling in the high level period or the low level period of the sampling signal.

  The pattern detection unit 65A has a function of determining whether or not the partial signal 56 is included in the sampling signal obtained by sampling the reception signal RxA25 of the communication channel 10A. That is, the pattern detection unit 65A detects that the partial signal 56 is included in the sampling signal using the edge detection signal, the edge type signal, and the counter output signal. Then, the pattern detection unit 65A outputs the communication speed detection signal A to the higher-level communication unit 66.

  When the upper communication unit 66 detects either the communication speed detection signal A or the communication speed detection signal B from the pattern detection unit 65A and the pattern detection unit 65B, it outputs a communication speed detection signal 67.

  As described above, the communication speed detection unit 12 operates and can automatically detect the communication speed.

  FIG. 7 is a state transition diagram illustrating the operation of the communication speed detection unit according to the first embodiment of this invention. With reference to FIG. 7, the communication speed detection operation shown in FIGS. 3 to 6 will be described.

  FIG. 7 is a diagram illustrating state transitions of the communication speed detection unit 61A of the communication speed detection unit 12, the pattern detection unit 65A of the communication speed detection unit 61B, and the pattern detection unit 65B. The pattern detection unit 65A has the same configuration as the pattern detection unit 65B. Here, the state transition of the pattern detection unit 65A of the communication speed detection unit 61A will be described, and the description of the pattern detection unit 65B will be omitted.

  The pattern detection unit 65A of the communication speed detection unit 61A is in an initial state of monitoring the sampling signal of the reception signal RxA25.

  And there are the following six conditions as the condition for the state transition.

1) Condition 10
A rising edge is detected, and the counter count is 7, 8, or 9.

2) Condition 11
The falling edge is detected, and the count number of the counter is 7, 8, or 9.

3) Condition 20
A rising edge is detected, and the counter count is 15, 16 or 17.

4) Condition 21
A falling edge is detected, and the count number of the counter is 15, 16 or 17.

5) Condition 30
A rising edge is detected, and the counter count is 31, 32, or 33.

6) Condition 31
A falling edge is detected, and the counter count is 31, 32, or 33.

  Conditions 10 and 11 are conditions for detecting a low level and a high level at a communication speed of 10 Mbps. Conditions 20 and 21 are conditions for detecting a low level and a high level at a communication speed of 5 Mbps. Conditions 30 and 31 are conditions for detecting a low level and a high level at a communication speed of 2.5 Mbps.

  With reference to FIG. 7, the state transition of the pattern detection unit 65 </ b> A will be described with an example of an operation for detecting a communication speed of 10 Mbps.

  When the rising edge is detected in the initial state and the count number of the counter is 8, the state of the pattern detection unit 65A transitions from the initial state to R10 Step 1 according to the condition 10. The low level in the second half of the BSS of the partial signal 56 is detected by the determination under the condition 10.

  Next, when the falling edge is detected and the count number of the counter is 8, the state of the pattern detection unit 65A transitions from R10Step1 to R10Step2 according to the condition 11. Based on the determination under condition 11, the first High level of the communication speed detection pattern of the partial signal 56 is detected.

  When the rising edge is detected and the count number of the counter is 8, the state of the pattern detection unit 65A transitions from R10Step2 to R10Step3 according to the condition 10. Based on the determination under the condition 10, the first Low level of the communication speed detection pattern of the partial signal 56 is detected.

  Furthermore, when the falling edge is detected and the count number of the counter is 8, the state of the pattern detection unit 65A transitions from R10Step3 to R10Step4 according to the condition 11. Based on the determination under condition 11, the second High level of the communication speed detection pattern of the partial signal 56 is detected.

  When the rising edge is detected and the count number of the counter is 8, the state of the pattern detection unit 65A transitions from R10Step4 to R10Step5 according to the condition 10. Based on the determination under the condition 10, the second Low level of the communication speed detection pattern of the partial signal 56 is detected.

  Next, when the falling edge is detected and the count number of the counter is 8, the state of the pattern detection unit 65A changes from R10Step5 to R10Step6 according to the condition 11. Based on the determination under condition 11, the third High level of the communication speed detection pattern of the partial signal 56 is detected.

  When the rising edge is detected and the count number of the counter is 8, the state of the pattern detection unit 65A transitions from R10Step6 to R10Step7 according to the condition 10. By the determination under the condition 10, the third Low level of the communication speed detection pattern of the partial signal 56 is detected.

  Further, when the falling edge is detected and the count number of the counter is 8, the state of the pattern detection unit 65A transitions from R10Step 7 to the communication speed 10 Mbps detection state according to the condition 11. As a result of the determination under condition 11, the fourth High level of the communication speed detection pattern of the partial signal 56 is detected.

  By this series of state transitions, the pattern detection unit 65A enters a state in which the partial signal 56 is detected, and enters a state in which it is determined that the communication speed is 10 Mbps.

  In each transition, the count number of the counter unit 64A has been described as 8. However, the count number may be in the range of 7 to 9. The state of the pattern detection unit 65A is returned to the initial state if the count number is outside the range of 7 to 9.

  Thus, the pattern detection unit 65A completes the detection of the partial signal 56. Then, the pattern detection unit 65A determines that the communication speed is 10 Mbps from the condition transition conditions 10 and 11 and outputs a communication speed detection signal A indicating a communication speed of 10 Mbps.

  Similarly, the pattern detection unit 65A determines the communication speed of 5 Mbps from the state transitions according to the conditions 20 and 21, and determines the communication speed of 2.5 Mbps from the state transitions according to the conditions 30 and 31.

  The upper communication unit 66 detects either the communication speed detection signal A or the communication speed detection signal B from the pattern detection unit 65A and the pattern detection unit 65B, and generates a communication speed detection signal 67 indicating the communication speed. Output.

  As described above, the communication speed detection unit 12 can automatically detect the communication speed.

  FIG. 8 is a timing chart showing the operation of the first embodiment of the present invention. With reference to FIG. 8, the communication speed detection operation shown in FIGS. 3 to 7 will be described.

  FIG. 8 is a timing chart of the pattern detection unit 65A of the communication speed detection unit 61A of the communication speed detection unit 12. The pattern detection unit 65A has the same configuration as the pattern detection unit 65B. Here, the communication speed detection operation will be described as a timing chart of the pattern detection unit 65A, and the description of the pattern detection unit 65B will be omitted.

  The pattern detection unit 65A is in an initial state (initial state shown in FIG. 7) in which the sampling signal of the reception signal RxA25 is monitored.

  From T0, the pattern detection unit 65A of the communication speed detection unit 61A starts the detection operation of the partial signal 56 including the communication speed detection pattern. The sampling unit 62A of the communication speed detection unit 61A samples the reception signal RxA25 with the clock signal 60 and outputs a sampling signal.

  At T1, the edge detection unit 63A of the communication speed detection unit 61A detects a falling edge from the sampling signal, and outputs a counter reset signal to the counter unit 64A. At T2, the counter unit 64A receives the counter reset signal and resets the counter value to 1. After the reset, the counter 64A counts the clock signal 60.

  Here, at T0, it is assumed that the low level of the reception signal RxA25 starts after the BSS of the partial signal 56.

  Next, the communication speed detection unit 61A will describe the falling edge that changes to Low at the latter stage of the BSS and the subsequent reception operation at the Low level.

  First, during the period from T0 to T4, the low level of the reception signal RxA25 (the low level subsequent to the BSS) is maintained. At T4, the communication speed detection pattern changes to the first High level. At T5, the edge detection unit 63A detects this rising edge and outputs a counter reset signal. At T6, the counter unit 64A resets the counter value to 1. Here, since there is a period of 8 clocks from T2 to T6, the counter value of the counter unit 64A advances from 1 to 8. Therefore, at T6, the counter unit 64A outputs 8 which is a value immediately before reset as a counter output signal. This counter output signal indicates that the immediately preceding received signal RxA25 has a length of 8 clocks.

  The edge detection unit 62A outputs an edge detection signal and an edge type signal to the pattern detection unit 65A at T2 and T6 one clock after the edge detection. The edge type signal changes to a low level when a falling edge is detected, and changes to a high level when a rising edge is detected. At T6, the pattern detection unit 65A detects the edge detection signal, and it is a rising edge based on the edge type signal and the count value is 8 based on the counter output signal. It is determined that the condition 10 is met. Then, at T7, the pattern detection unit 65A changes the pattern detection state from the initial state to the state of R10Step1. As a result, the Low level of the subsequent stage of the BSS of the partial signal 56 can be detected.

  Next, the operation for detecting the first High level of the communication speed detection pattern of the partial signal 56 will be described.

  At T4, the low level after the BSS changes to the first high level of the communication speed detection pattern. At T5, the edge detection unit 63A detects a rising edge from the sampling signal, and outputs a counter reset signal to the counter unit 64A. At T6, the counter unit 64A resets the count value to 1. After the reset, the counter unit 64A counts the clock signal 60. During the period from T4 to T8, the High level of the reception signal RxA25 (the first High level of the communication speed detection pattern) is maintained. At T8, the communication speed detection pattern changes to the first low level. At T9, the edge detection unit 63A detects a falling edge from the sampling signal and outputs a counter reset signal. At T10, the counter unit 64A resets the counter value to 1. Here, since there is a period of 8 clocks from T6 to T10, the counter value of the counter unit 64A advances from 1 to 8. Therefore, at T10, the counter unit 64A outputs 8 which is a value immediately before reset as a counter output signal. This counter output signal indicates that the immediately preceding received signal RxA25 has a length of 8 clocks.

  The edge detection unit 62A outputs an edge detection signal and an edge type signal to the pattern detection unit 65A at T10 one clock after the edge detection. At this time, the edge type signal becomes the low level when the falling edge is detected. At T10, the pattern detection unit 65A detects the edge detection signal, and it is a falling edge based on the edge type signal and the count value is 8 based on the counter output signal. It is determined that the condition 11 shown is satisfied. At T11, the pattern detection unit 65A changes the pattern detection state from the state of R10Step1 to the state of R10Step2. As a result, the first High level of the communication speed detection pattern of the partial signal 56 can be detected.

  Next, the state of the pattern detection unit 65A is the first low level, the second high level, the second low level, the third high level, and the third low level of the communication speed detection pattern of the partial signal 56. The fourth high-level received signal RxA25 is sequentially received, and the process proceeds to R10Step7 in FIG. 7 by the same operation as described above.

  At T12, the reception signal RxA25 changes to the fourth low level of the communication speed detection pattern. At T13, the edge detection unit 63A detects a falling edge from the sampling signal and outputs a counter reset signal. At T14, the counter unit 64A resets the counter value to 1. Here, since there is a period of 8 clocks until T14, the counter value of the counter unit 64A advances from 1 to 8. Therefore, at T14, the counter unit 64A outputs 8 which is a value immediately before reset as a counter output signal. This counter output signal indicates that the immediately preceding received signal RxA25 has a length of 8 clocks.

  The edge detection unit 62A outputs the edge detection signal and the edge type signal to the pattern detection unit 65A at T14 one clock after the edge detection. At this time, the edge type signal becomes the low level when the falling edge is detected. At T14, the pattern detection unit 65A detects the edge detection signal, and it is a falling edge based on the edge type signal and the count value is 8 based on the counter output signal. It is determined that the condition 11 shown is satisfied. At T15, the pattern detection unit 65A changes the pattern detection state from the state of R10 Step 7 to the state of communication speed 10 Mbps detection.

  As a result, the pattern detection unit 65A can detect the final High level of the partial signal 56. Then, the pattern detection unit 65A determines from the received signal RxA25 that the communication speed of the communication channel 10A is 10 Mbps.

  In each transition, the count number of the counter unit 64A has been described as 8. However, the count number may be in the range of 7 to 9. If the count number is outside the range of 7 to 9, the state of the pattern detection unit 65A is returned to the initial state shown in FIG.

  As described above, the pattern detection unit 65A sequentially transitions from the initial state shown in FIG. 7 to the state where the communication speed is 10 Mbps, and detects the partial signal 56. Then, from the state transition conditions 10 and 11, the pattern detection unit 65A determines that the communication speed is 10 Mbps, and outputs a communication speed detection signal A indicating a communication speed of 10 Mbps at T15.

  Similarly, the pattern detection unit 65A determines a communication speed of 5 Mbps from the state transitions according to the conditions 20 and 21. Further, the pattern detection unit 65A determines the communication speed of 2.5 Mbps from the state transitions according to the conditions 30 and 31.

  When the upper communication unit 66 detects either the communication speed detection signal A or the communication speed detection signal B from the pattern detection unit 65A and the pattern detection unit 65B, the communication speed detection indicating the communication speed is performed at T16. A signal 67 is output. As described above, the communication speed detection unit 12 can automatically detect the communication speed.

As described above, in the present embodiment, a communication device added to the communication system automatically detects the communication speed of the communication system and automatically sets communication parameters. Therefore, the communication system according to the present embodiment is advantageous in that a communication device can be easily added and convenience is high.
(Second Embodiment)
Next, a second embodiment of the present invention will be described.

  FIG. 9 is a block diagram showing a configuration of a communication system according to the second exemplary embodiment of the present invention. With reference to FIG. 9, the structure of the communication system 2 of the 2nd Embodiment of this invention is demonstrated.

  The communication system 2 in FIG. 9 includes a communication path 10, communication devices A101 to 10n, and a communication device B110.

  The communication devices A101 to 10n are already connected to each other via the communication path 10. The communication device B110 is a communication device newly added to the communication system 2.

  At least one of the communication devices A 101 to 10 n includes a communication speed detection pattern transmission unit 11 and a device addition detection unit 92. In FIG. 9, the communication device A 101 includes a communication speed detection pattern transmission unit 11 and a device addition detection unit 92. The device addition detection unit 92 receives a device addition signal indicating that a device has been added from the communication path 10.

  The communication device B110 includes a communication speed detection unit 12 and a device additional transmission unit 91. The device addition sending unit 91 sends a device addition signal to the communication path 10 when the communication device B 110 is connected to the communication path 10.

  In the communication system 2 of the second embodiment, a device addition detection unit 92 and a device addition sending unit 91 are added to the communication device A 101 and the communication device B 110, respectively. The communication of the first embodiment of FIG. It is different from the system 1. The same components are denoted by the same names and the same numbers, and the description thereof is omitted.

  With reference to FIG. 9, the operation of the communication system 2 according to the second exemplary embodiment of the present invention will be described. The device addition sending unit 91 of the communication device B 110 sends a device addition signal to the communication path 10 when the communication device B 110 is connected to the communication path 10.

  The device addition detection unit 92 of the communication device A 101 receives a device addition signal from the communication path 10. Then, the communication apparatus A 101 transmits the same communication speed detection pattern and communication parameters as those described in the first embodiment to the communication path 10. As a result, the added communication device B110 can automatically detect the communication speed, acquire the communication parameters, and communicate with the other communication devices A101 to 10n, as in the first embodiment. Become.

  And the apparatus addition transmission part 91 of communication apparatus B110 stops transmission of an apparatus addition signal, when communication is attained. The device addition detection unit 92 of the communication device A 101 detects the stop of transmission of the device addition signal, and stops the transmission of the communication speed detection pattern and the communication parameter.

  FIG. 10 is a block diagram illustrating an internal configuration of a communication apparatus according to the second embodiment of this invention. With reference to FIG. 10, the structure of the communication apparatus D130 of the 2nd Embodiment of this invention is demonstrated. The internal components of the communication device A101 and the communication device B110 are common. Therefore, for convenience of explanation, the communication device A101 and the communication device B110 will be described using the communication device D130 that includes both the communication device A101 and the internal components of the communication device B110.

  The communication device D130 is different from the first embodiment of FIG. 2 in that a device addition sending unit 91 and a device addition detection unit 92 are added and a signal line 10C is added to the communication path 10. Yes. The same name is assigned to the same configuration and the same number, and the description is omitted.

  The device addition sending unit 91 and the device addition detection unit 92 are the same as those described with reference to FIG.

  The signal line 10C transmits the device addition signal sent from the device addition sending unit 91 to the device addition detection unit 92 of another communication device D130.

  With reference to FIG. 10, the operation of the communication apparatus D130 according to the second embodiment of the present invention will be described.

  The communication device C120 can operate as the communication device B110 in FIG. In this case, when the communication device D130 as the communication device B110 is added to the communication path 10, the device addition transmission unit 91 transmits a device addition signal to the signal line 10C of the communication path 10. Further, the device addition sending unit 91 outputs a self device signal indicating that the own device has been added to the communication speed detecting unit 12 and the device addition detecting unit 92.

  The communication speed detection unit 12 that has received the own device signal starts a communication speed detection operation. In addition, the device addition detection unit 92 that has received the own device signal stops the device detection operation.

  The device addition signal of the communication device D130 added to the communication path 10 is transmitted to another communication device D130 via the signal line 10C of the communication path 10.

  The communication device C130 can also operate as the communication device A101 in FIG. In this case, the device addition detection unit 92 of the communication device D130 as the communication device A101 receives the device addition signal. The device addition detection unit 92 receives the device addition signal and outputs the device addition detection signal to the communication speed detection pattern sending unit 11 and the parameter setting unit 22.

  Upon receiving the device addition detection signal, the communication speed detection pattern sending unit 11 starts sending the communication speed detection pattern. The parameter setting unit 22 starts sending communication parameters.

  As described in the first embodiment, the communication device C130 as the added communication device B110 automatically increases the communication speed by the communication speed detection unit 12 by the above operation by the communication device C130 as the communication device A101. To detect. And the communication apparatus C130 acquires a communication parameter in the automatic configuration part 23. FIG. Therefore, thereafter, the added communication device C130 can perform communication.

  Note that the added communication device D130 outputs a communication setting completion signal from the communication controller unit 21 to the device addition sending unit 91 when communication is possible. Upon receiving the communication setting completion signal, the device addition sending unit 92 stops outputting the device addition signal and the own device signal. When the output of the own apparatus signal is stopped, the communication speed detecting unit 12 stops the operation of detecting the communication speed. Then, the device addition detection unit 92 starts a device detection operation.

  On the other hand, the device addition detection unit 92 of the communication device D130 serving as the communication device A101 receives the stop of sending the device addition signal via the signal line 10C and stops outputting the device addition detection signal. As a result, the communication speed detection pattern sending unit 11 stops sending the communication speed detection pattern. The parameter setting unit 22 stops sending communication parameters.

  Thus, in this embodiment, the added communication device B110 notifies the communication device A101 that a device has been added. Then, the communication apparatus A 101 starts outputting the communication speed detection pattern and communication parameters necessary for adding the apparatus, and stops outputting the communication speed detection pattern and communication parameters which are unnecessary when the apparatus addition is completed. Further, the communication device B110 starts the operation of the communication speed detecting unit 12 necessary for adding the device and stops the operation of the communication speed detecting unit 12 which becomes unnecessary when the device addition is completed.

  As described above, this embodiment increases the convenience of the communication system by transmitting necessary information only when adding a device to the communication path 10 and operating each part of the necessary communication device. It is possible to improve communication efficiency and system power consumption.

  Note that the present invention is not limited to the above-described embodiments, and various modifications and changes can be made without departing from the spirit of the present invention.

  For example, in the embodiment, the communication channel of the communication path 10 has been described as being duplexed, but the channel may not be duplexed. Conversely, the communication channels of the communication path 10 may be further multiplexed.

  Furthermore, as described above, at least one of the communication devices constituting the existing communication system only needs to have a function of transmitting a communication speed detection pattern and communication parameters to the communication path 10.

  The added communication device has a function of receiving a signal including a communication speed detection pattern from the communication path 10 to automatically detect the communication speed, and then acquiring a communication parameter from the communication path 10.

  In this embodiment, the three communication speeds of 10 Mbps, 5 Mbps, and 2.5 Mbps have been described, but other combinations of communication speeds may be used.

  In the present embodiment, the signal transmitted and received on the communication path 10 has been described as being a binary signal, but may be a multilevel signal. In other words, the signal of the communication channel 10 is taken in and sampled, and the waveform of the partial signal including the communication speed detection pattern changes in a cycle that is the reciprocal of the modulation speed (symbol interval) covering all the modulation signal levels. do it.

  At this time, the number of samplings in the period of one symbol is s, the sampling period is t seconds / time, and the number covering the modulation signal level, that is, the multi-value number is 2 m (where m is an integer of 1 or more). For example, since the number of bits of information corresponding to one symbol is mbit, the communication speed S (bps) is obtained by S = m / (s × t).

  Furthermore, the communication apparatus in the present embodiment may be a terminal, a board, a module, or a device that has a communication function. That is, the communication device in the present embodiment may be anything that is connected to a communication path and performs a communication function.

DESCRIPTION OF SYMBOLS 1, 2 Communication system 10 Communication path 10A, 10B Communication channel 10C Signal line 11 Communication speed detection pattern transmission part 12 Communication speed detection part 21 Communication controller part 22 Parameter setting part 23 Automatic configuration part 24A, 24B Bus driver 25 Reception signal RxA
26 Received signal RxB
51 Data frame 52 Header part 53 Payload part 54 CRC part 55 Communication speed detection pattern 56 Partial signal for communication speed detection 60 Clock signal 61A, 61B Communication speed detection part 62A, 62B Sampling part 63A, 63B Edge detection part 64A, 64B Counter unit 65A, 65B Pattern detection unit 66 Host communication unit 67 Communication speed detection signal 91 Device addition sending unit 92 Device addition detection unit 101, 102, 10n Communication device A
110 Communication device B
120 Communication device C
130 Communication device D

Claims (10)

A first communication device comprising sending means for sending to the communication path a pattern that changes in sequence and covers all modulation signal levels in a reciprocal period of the modulation speed;
A communication system, comprising: a second communication device comprising detection means for detecting the communication speed by sampling the pattern received from the communication path at predetermined intervals. The sending means sends a communication parameter to the communication path,
The communication system according to claim 1, wherein the detection unit acquires the communication parameter from the communication path, and sets the communication speed and the communication parameter in the second communication device. The detection means includes
Sampling means for sampling the pattern at predetermined intervals from the communication path;
Edge type detection means for detecting a change in the signal level of the pattern from the sampling result;
The communication system according to claim 1, further comprising a counting unit that counts sampling during a period in which the signal level of the pattern is maintained. The communication system according to claim 3, wherein the counting unit determines that the count number by the count is within a predetermined range. The communication system according to claim 4, wherein the detection unit detects a signal including the pattern from the change in the detected signal level and the determination result of the count number. The first communication device includes receiving means for receiving a device addition notification from the communication path, and the second communication device includes transmission means for transmitting the device addition notification when added to the communication path. The communication system according to any one of claims 1 to 5, further comprising: It comprises detection means for detecting a communication speed by sampling the pattern received from a device that sends out a pattern that changes sequentially covering all modulation signal levels in a cycle that is a reciprocal of the modulation speed at a predetermined interval. A communication speed automatic detection device. The communication speed automatic detection device according to claim 7, further comprising setting means for setting the communication speed. The first communication speed is detected by sampling the first pattern that covers all the modulation signal levels in the reciprocal period of the first modulation speed and sequentially changing the first pattern at a predetermined interval. Sending means for sending to a device comprising detection means;
The second pattern received from the device that sends out the second pattern that sequentially changes and covers all the modulation signal levels in the reciprocal period of the second modulation rate is sampled at a predetermined interval, Detection means for detecting the communication speed;
A communication apparatus comprising: Send out a pattern that changes sequentially covering all modulation signal levels in the reciprocal period of the modulation speed to the communication path,
A communication speed setting method, wherein the communication speed is detected by sampling the pattern received from the communication path at a predetermined interval.

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