Reception device and communication system

Abstract

To provide a reception device and a communication system that are capable of more appropriately compensating for communication data.SOLUTION: A reception device includes: input pins INP2, INN2 to which communication data in which a valid period and a blank period are alternatively continued is input; a compensation circuit 202 which applies compensation corresponding to a set value to the communication data; a test circuit 212 which tests a compensation result by the compensation circuit which corresponds to the set value during the blank period; and an adjustment circuit 214 which adjusts the set value based on a test result of the compensation result by the test circuit. The compensation circuit applies compensation corresponding to each of a first test value and a second test value included in a test range of the set value to the communication data in the blank period. The test circuit tests the compensation result corresponding to each of the first test value and the second test value. The adjustment circuit adjusts the set value such that the set value is equal to a value between a first set value based on a compensation result corresponding to the first test value and a second set value based on a compensation result corresponding to the second test value in the valid period.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a receiving device and a communication system. [Background technology]

[0002] Conventionally, technologies for transmitting and receiving data between multiple devices have been developed. Some devices for receiving data have an equalizer function for compensating for the received data. A receiving device having an equalizer function is described in, for example, Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-165433 A

[0004] [overview] However, when the surrounding environment changes (for example, temperature changes) and the quality of the communication data changes, the setting value of the equalizer function becomes inappropriate, and the communication data may not be compensated appropriately. For this reason, it is preferable to more appropriately adjust the setting value of the equalizer function.

[0005] The present disclosure has been made in light of these circumstances, and one of its exemplary objectives is to provide a receiving device and a communication system that can more appropriately compensate communication data.

[0006] One aspect of the present disclosure is a receiving device. The receiving device includes an input pin to which communication data having valid periods and blank periods alternately is input, a compensation circuit that applies compensation to the communication data according to a set value, an inspection circuit that inspects a compensation result by the compensation circuit according to the set value during the blank period, and an adjustment circuit that adjusts the set value based on an inspection result of the compensation result by the inspection circuit. During the blank period, the compensation circuit applies compensation to the communication data according to each of a first inspection value and a second inspection value included in an inspection range of the set value. The inspection circuit inspects the compensation results according to each of the first inspection value and the second inspection value. The adjustment circuit adjusts the set value so that the set value becomes a value between a first set value based on the compensation result based on the first inspection value and a second set value based on the compensation result based on the second inspection value during the valid period.

[0007] Another aspect of the present disclosure is a communication system comprising: the receiving device; and a transmitting device that transmits communication data to the receiving device.

[0008] Any combination of the above components and conversion of the expressions of the present disclosure between methods, devices, systems, etc. are also valid aspects of the present disclosure. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram of a communication system according to one embodiment of the present disclosure. [Diagram 2] FIG. 2 is a timing chart for explaining the operation of the automatic adjustment circuit according to the reference technology. [Diagram 3] FIG. 3 is a block diagram of an auto-tuner according to one embodiment of the present disclosure. [Figure 4] FIG. 4 is a timing chart for explaining an example of the operation of the automatic adjuster at the time of start-up to determine the range of set values ​​within which no error occurs in the compensation result. [Diagram 5] FIG. 5 is a diagram showing an example of a result of judging whether the compensation result is acceptable or not. [Figure 6]FIG. 6 is a diagram for explaining a first example of a method for adjusting the set value. [Figure 7] FIG. 7 is a diagram for explaining a second example of the method for adjusting the set value. [Figure 8] FIG. 8 is a timing chart for explaining an example of the operation of the automatic adjuster. [Figure 9] FIG. 9 is a timing chart for explaining an example of an operation in which the automatic adjuster checks the compensation result during the blank period. [Figure 10] FIG. 10 is a flowchart for explaining an example of the operation of the second device according to the present embodiment. [Figure 11] FIG. 11 is a timing chart for explaining the flow of the start-up inspection process shown in FIG.

[0010] [Detailed Description] (overview) A summary of some exemplary embodiments of the present disclosure will be described. This summary is intended to provide a simplified overview of some concepts of one or more embodiments for a basic understanding of the embodiments as a prelude to the detailed description that follows, and is not intended to limit the scope of the invention or disclosure. This summary is not intended to be an exhaustive overview of all possible embodiments, nor is it intended to identify key elements of all embodiments or to delineate the scope of some or all aspects. For convenience, the term "one embodiment" may be used to refer to one embodiment (example or variant) or multiple embodiments (examples or variants) disclosed in this specification.

[0011] A receiving device according to an embodiment includes an input pin to which communication data having valid periods and blank periods alternately is input, a compensation circuit that applies compensation to the communication data according to a set value, an inspection circuit that inspects a compensation result by the compensation circuit according to the set value during the blank period, and an adjustment circuit that adjusts the set value based on an inspection result of the compensation result by the inspection circuit. The compensation circuit applies compensation to the communication data according to a first inspection value and a second inspection value included in an inspection range of the set value during the blank period. The inspection circuit inspects the compensation results according to the first inspection value and the second inspection value. The adjustment circuit adjusts the set value so that the set value becomes a value between a first set value based on the compensation result based on the first inspection value and a second set value based on the compensation result based on the second inspection value during the valid period.

[0012] According to this configuration, the setting value of the compensation circuit can be dynamically compensated in accordance with the result of checking the compensation result, which makes it possible to more appropriately compensate the communication data.

[0013] In one embodiment, the compensation circuit may apply compensation to the communication data according to each of a plurality of test values ​​included in an initial test range of the set value. The test circuit may test the compensation results according to each of the plurality of test values, and set the test range as a communication range within the initial test range where no error occurs in the compensation result based on the test result.

[0014] In one embodiment, when the initial test range includes multiple communication ranges, the test circuit may set the widest range of the multiple communication ranges as the test range.

[0015] In one embodiment, the first test value may be a minimum value of a test range and the second test value may be a maximum value of the test range.

[0016] In one embodiment, the test circuit may update the minimum value and the maximum value of the test range based on the compensation results by the compensation circuit in response to the first test value and the second test value, respectively.

[0017] In one embodiment, the adjustment circuit may adjust the set value so that the set value becomes the average value of the updated minimum value of the inspection range and the updated maximum value of the inspection range during the valid period.

[0018] In one embodiment, the inspection circuitry may inspect the compensation result based on the eye opening of the compensation result.

[0019] In one embodiment, the compensation result may be a result of the compensation circuit applying compensation according to a set value to data during a blank period included in the communication data.

[0020] A communication system according to one embodiment includes the receiving device and a transmitting device that transmits communication data to the receiving device.

[0021] According to this configuration, the setting value of the compensation circuit can be dynamically compensated in accordance with the result of checking the compensation result, which makes it possible to more appropriately compensate the communication data.

[0022] (Embodiment) Hereinafter, preferred embodiments will be described with reference to the drawings. The same or equivalent components, parts, and processes shown in each drawing will be given the same reference numerals, and duplicated descriptions will be omitted as appropriate. In addition, the embodiments are illustrative and do not limit the disclosure and invention, and all features and combinations thereof described in the embodiments are not necessarily essential to the disclosure and invention.

[0023] In this specification, "a state in which component A is connected to component B" includes not only a case in which component A and component B are directly physically connected to each other, but also a case in which component A and component B are indirectly connected to each other via other components that do not substantially affect the electrical connection state between them or that do not impair the function or effect achieved by their combination.

[0024] Similarly, "a state in which component C is connected (provided) between components A and B" includes not only the case in which components A and C, or components B and C, are directly connected to each other, but also the case in which they are indirectly connected to each other via other components that do not substantially affect the electrical connection between them or that do not impair the functions or effects achieved by their combination.

[0025] <Communication system configuration> 1 is a block diagram of a communication system 1 according to an embodiment of the present disclosure. The communication system 1 includes a first device 10 and a second device 20 connected via a differential transmission path 15. The first device 10 is coupled to a corresponding end of the differential transmission path 15 via capacitors Cp1 and Cn1. The second device 20 is coupled to a corresponding end of the differential transmission path 15 via capacitors Cp2 and Cn2. The first device 10 and the second device 20 are capable of bidirectional serial transmission. For example, the first device 10 and the second device 20 can transmit and receive communication data such as image data to and from each other.

[0026] The first device 10 includes a driver 102, a parallel-serial converter 106, and signal pins INP1 and INN1.

[0027] First parallel data D1P to be transmitted to the second device 20 from outside (or inside) the first device 10 TX The first parallel data D1P is generated. TX The contents of the first parallel data D1P are not particularly limited. TX may include image data, audio data, or other data. In this embodiment, the first parallel data D1P TX The parallel-serial converter 106 converts the first parallel data D1P TX The first serial data D1S TX Convert to.

[0028] The driver 102 is coupled to one end of the differential transmission line 15 via the signal pins INP1 and INN1. The driver 102 outputs the first serial data D1S TXIn response to this, the first device 10 drives the differential transmission path 15. As a result, the first serial data D1S is transmitted from the first device 10 to the second device 20. The first serial data D1S is communication data in which valid periods and blank periods alternate, as will be described later in detail.

[0029] The second device 20 includes a compensation circuit 202, a serial-to-parallel converter 206, an automatic adjuster 210, and signal pins INP2 and INN2 (input pins).

[0030] The compensation circuit 202 is coupled to a corresponding one end of the differential transmission path 15 via signal pins INP2 and INN2. The compensation circuit 202 receives the first serial data D1S transmitted from the first device 10. The serial-to-parallel converter 206 converts the first serial data D1S received by the compensation circuit 202 into RX The first parallel data D1P RX Convert the first parallel data D1P RX may be output to the outside.

[0031] The compensation circuit 202 has an equalizer function and performs compensation according to a set value on the first serial data D1S input via the signal pins INP2 and INN2. When the set value is appropriate, the compensation circuit 202 performs compensation on the data during the valid period of the first serial data D1S, thereby restoring the waveform of the first serial data D1S that has been attenuated due to, for example, long-distance transmission.

[0032] During the blank period of the first serial data D1S, the compensation circuit 202 performs compensation on the first serial data D1S according to the first and second test values ​​included in the test range of the set value. In this embodiment, as described later, the compensation according to these two test values ​​is performed on the first serial data D1S, and a set value according to the result is set in the compensation circuit 202. This makes it possible to dynamically adjust the set value and suppress errors from occurring in the compensation result during the valid period.

[0033] The compensation circuit 202 may compensate for the data of the blank period included in the first serial data D1S during the blank period of the first serial data D1S. By using the data of the blank period, it is not necessary to add test data to the first serial data D1S, and it is possible to more easily test the compensation result.

[0034] The compensation circuit 202 may perform compensation for each of a plurality of test values ​​included in the initial test range of the set value on the first serial data D1S, for example, at the time of startup. By using the compensation result, it becomes possible to set the initial value of the test range at the time of startup.

[0035] The automatic adjuster 210 receives the first parallel data D1P RX The control signal CTRL is transmitted to the compensation circuit 202. The automatic adjuster 210 according to the present embodiment receives the first parallel data D1P RX The compensation result by the compensation circuit 202 is checked based on the above, and the setting value of the compensation circuit 202 is adjusted using the control signal CTRL according to the checking result.

[0036] <Reference technologies and their issues> The operation of the communication system according to the reference technology will be described. The communication system according to the reference technology has a configuration in which the automatic adjuster 210 included in the second device 20 according to the present embodiment is replaced with an automatic adjustment circuit according to the reference technology. The automatic adjustment circuit according to the reference technology adjusts the setting value of the compensation circuit 202 at startup and maintains that value thereafter. If an error occurs in the compensation result during serial communication, the automatic adjustment circuit readjusts the setting value.

[0037] 2 is a timing chart for explaining the operation of the automatic adjustment circuit according to the reference technology. FIG. 2 shows the first serial data D1S received by the compensation circuit 202, the set value SET set in the compensation circuit 202, the communication error flag ERR1, and the range RNG1 of the set value where no error occurs in the compensation result.

[0038] The first serial data D1S is communication data in which valid periods T1, T3 and blank periods T2, T4 alternate. The valid periods T1, T3 are periods that include data that is effectively used (hereinafter also referred to as "valid data"), specifically, data that represents an image to be displayed on the screen. The blank periods T2, T4 are periods that include data that is not effectively used (hereinafter also referred to as "blank data"), specifically, data that represents an image that is not displayed on the screen (e.g., a black image).

[0039] The compensation circuit 202 applies compensation to the first serial data D1S according to a set value SET of 15 during a valid period T1 (timings t1 to t3). At this time, a range RNG1 of set values ​​in which no error occurs in the compensation result is 14 to 24, and the set value SET is included in this range RNG1. Therefore, no error occurs in the compensation result, and the communication error flag ERR1 becomes low.

[0040] The range RNG1 in which no error occurs in the compensation result varies depending on the conditions of the surrounding environment (such as temperature), and at timing t2, it changes from 14 to 24 to 15 to 25. Since the set value SET remains within this range RNG1 at timing t2, the communication error flag ERR1 is maintained low.

[0041] At timing t3, the period of the first serial data D1S switches from the valid period T1 to the blank period T2, and compensation by the compensation circuit 202 is stopped. After that, at timing t4, compensation by the compensation circuit 202 is resumed.

[0042] At timing t5, the range RNG1 of the set value in which no error occurs in the compensation result changes from 15-25 to 16-26. At this time, the set value SET (15) falls outside this range RNG1, so an error occurs in the compensation result, and the communication error flag ERR1 becomes high. When the communication error flag ERR1 becomes high, the automatic adjustment circuit according to the reference technology starts adjusting the set value SET so that the set value SET falls within the changed range RNG1. Thereafter, the communication error flag ERR1 remains high until the set value SET is appropriately adjusted, and appropriate compensation cannot be applied to the first serial data D1S, for example, during the valid period T4 from timing t6 to t7.

[0043] In this way, the automatic adjustment circuit according to the reference technology starts adjusting the setting value of compensation circuit 202 after a communication error occurs. For this reason, in the communication system according to the reference technology, if a communication error occurs due to a change in the quality of serial communication while serial communication is being performed, the receiving device may not be able to properly receive data until the setting value is set to an appropriate value.

[0044] <Automatic adjustment circuit> 3 is a block diagram of an automatic regulator 210 according to an embodiment of the present disclosure. The automatic regulator 210 according to the present embodiment includes an inspection circuit 212 and an adjustment circuit 214.

[0045] The check circuit 212 checks the result of compensating the first serial data D1S by the compensation circuit 202. Specifically, the check circuit 212 checks the compensation result by the compensation circuit 202 during each of the valid period and blank period of the first serial data D1S. The check circuit 212 checks the compensation result at the time of start-up and during serial communication.

[0046] In this embodiment, during serial communication, the inspection circuit 212 inspects the compensation results in the blank period according to the first and second inspection values ​​included in the inspection range of the set value. In this embodiment, the first inspection value is smaller than the second inspection value, and specifically, the first inspection value is the minimum value of the inspection range and the second inspection value is the maximum value of the inspection range.

[0047] In this embodiment, the setting value set in compensation circuit 202 is adjusted based on the minimum value and the maximum value of the inspection range. Inspection circuit 212 may update the minimum value and the maximum value of the inspection range based on the compensation results by compensation circuit 202 corresponding to the first inspection value and the second inspection value, respectively. By updating the minimum value and the maximum value of the inspection range based on the compensation results, it becomes possible to set a more appropriate setting value in compensation circuit 202.

[0048] In this embodiment, the inspection circuit 212 receives the first serial data D1S from the serial-to-parallel converter 206. RX The first parallel data D1P RX The check circuit 212 checks the compensation result based on the first parallel data D1P RX For example, the check circuit 212 may check the compensation result based on the error rate of the first parallel data D1P RX When there is no error (error rate=0), the compensation result may be determined as passed (communication possible). RX If there is an error (error rate>0), the compensation result may be judged as failing (error).

[0049] The inspection circuit 212 may inspect the compensation result based on the eye opening of the compensation result in addition to the error rate. For example, the inspection circuit 212 may inspect the compensation result based on the eye opening of the compensation result for each of the minimum value of the inspection range and the maximum value of the inspection range. For example, when the size of the eye opening is smaller than a predetermined size, the inspection circuit 212 may determine that the compensation result is unacceptable even if the error rate is 0. By using the eye opening to inspect the compensation result, the compensation result can be inspected with higher accuracy.

[0050] In addition, in determining the size of the eye opening, an offset may be provided to the gain as necessary. Also, the gain may be adjusted according to the compensation result based on the error rate. For example, if the error based on the error rate exceeds a threshold during a predetermined period, the gain may be decreased, and if the error based on the error rate does not exceed the threshold during the predetermined period, the gain may be increased.

[0051] For example, at startup, the inspection circuit 212 can inspect the compensation results corresponding to each of the multiple inspection values ​​included in the initial inspection range. Based on the inspection results, the inspection circuit 212 can set, as the inspection range, a communication range within the initial inspection range in which no error occurs in the compensation result. Using the set inspection range as an initial value, the compensation circuit 202 can perform compensation corresponding to this inspection range. The inspection range can be updated as appropriate according to the compensation results.

[0052] When the initial inspection range includes a plurality of communication ranges, the inspection circuit 212 can set the widest of the plurality of communication ranges as the inspection range. By using a wider communication range as the inspection range, it becomes possible to set a setting value that is less likely to cause an error.

[0053] The adjustment circuit 214 adjusts the set value set in the compensation circuit 202 based on the inspection result of the compensation result by the inspection circuit 212. Specifically, the adjustment circuit 214 adjusts the set value so that the set value set in the compensation circuit 202 is a value between a first set value based on the compensation result according to the first inspection value and a second set value based on the compensation result according to the second inspection value during the valid period. The adjustment circuit 214 may adjust the set value using a control signal CTRL. Since the compensation according to each of the first inspection value and the second inspection value is performed during the blank period, the serial communication is not affected even if these compensation results are unsuccessful. Therefore, it is possible to set an appropriate set value in the compensation circuit 202 while suppressing the influence on the serial communication.

[0054] The adjustment circuit 214 may adjust the setting value set in the compensation circuit 202 so that the setting value becomes the average value of the minimum value and the maximum value of the inspection range during the valid period. This makes it possible to set a setting value in the compensation circuit 202 that is less likely to cause errors.

[0055] In this embodiment, the minimum value and the maximum value of the inspection range may be updated according to the inspection result. The adjustment circuit 214 may adjust the setting value set in the compensation circuit 202 so that the setting value becomes the average value of the updated minimum value of the inspection range and the updated maximum value of the inspection range during the valid period. This makes it possible to set a more appropriate setting value in the compensation circuit 202 according to the update of the minimum value of the inspection range and the maximum value of the inspection range.

[0056] <Automatic Adjuster Operation> 4 is a timing chart for explaining an example of an operation in which automatic adjuster 210 determines a range of set value SET in which no error occurs in the compensation result at the time of startup. Here, automatic adjuster 210 sequentially changes set value SET within an initial inspection range (N=0 to 84). Automatic adjuster 210 determines a range of set value SET in which no error occurs in the compensation result, based on the compensation result according to the changing set value SET.

[0057] Automatic adjuster 210 operates in response to strobe signal STRB. The period of strobe signal STRB may be, for example, about 1 ms. Adjustment circuit 214 sequentially changes set value SET. When set value SET changes and waiting time Tw1 (for example, about 1 ms) has elapsed, inspection circuit 212 judges whether the compensation result according to set value SET passes or fails during inspection time Tchk (for example, about 1 to 8 ms). When the pass or fail of the compensation result is judged for all set values ​​(0 to 84), a range of set value SET in which no error occurs in the compensation result is determined.

[0058] Fig. 5 is a diagram showing an example of the result of judging whether the compensation result is pass or fail. Fig. 5 shows whether the compensation result is pass or fail for set values ​​of 0 to 84. In Fig. 5, pass is indicated by a circle and fail is indicated by a cross.

[0059] As shown in FIG. 5, when the set value is 0 to 17, 21, or 27 to 84, the compensation result is unsuccessful, and when the set value is 18 to 20 or 22 to 26, the compensation result is successful. In the example shown in FIG. 5, there are two ranges (18 to 20 and 22 to 26) of set values ​​(hereinafter also referred to as "communication possible ranges") in which no error occurs in the compensation result. In this case, the inspection circuit 212 may set the wider range (22 to 26) as the inspection range. Furthermore, the adjustment circuit 214 may set an initial value of the set value in the compensation circuit 202 based on this range. Specifically, the adjustment circuit 214 may set the average value (24) of the maximum value (26) and the minimum value (22) of this range as the set value.

[0060] 6 is a diagram for explaining a first example of a method for adjusting the set value. Here, in the inspection at the time of startup, when the set value is 12 to 18, the compensation result is passed, and when the set value is other than that, the compensation result is failed. Therefore, the communication range is 12 to 18. This communication range is set as the inspection range, and its minimum value is 12 and its maximum value is 18.

[0061] The automatic adjuster 210 according to this embodiment checks the compensation results for each of the minimum and maximum values ​​of the communicable range during the validity period of the communication data, and updates (adjusts) the set values ​​according to the check results.

[0062] In a first example, the adjustment circuit 214 lowers the minimum value of the communication range by 1 if the compensation result is acceptable, and raises the minimum value by 1 if the compensation result is unacceptable. The adjustment circuit 214 raises the maximum value of the communication range by 1 if the compensation result is acceptable, and lowers the maximum value by 1 if the compensation result is unacceptable. The adjustment circuit 214 adjusts the setting value to the average value of the minimum and maximum values ​​in response to changes in the minimum and maximum values.

[0063] For example, when the compensation results of both the minimum and maximum values ​​are fail, as in test 1-1, adjustment circuit 214 increases the minimum value from 12 to 13, decreases the maximum value from 18 to 17, and maintains the set value at 15. When the compensation result of the minimum value is fail and the compensation result of the maximum value is pass, as in test 1-2, adjustment circuit 214 increases the minimum value from 12 to 13, increases the maximum value from 18 to 19, and increases the set value from 15 to 16.

[0064] If the compensation results of both the minimum and maximum values ​​are pass, as in test 1-3, adjustment circuit 214 lowers the minimum value from 12 to 11, raises the maximum value from 18 to 19, and maintains the set value at 15. If the compensation result of the minimum value is pass and the compensation result of the maximum value is fail, as in test 1-4, adjustment circuit 214 lowers the minimum value from 12 to 11, lowers the maximum value from 18 to 17, and lowers the set value from 15 to 14.

[0065] 7 is a diagram for explaining a second example of the method for adjusting the set value. In the second example, as in the first example, in the inspection at the time of start-up, the compensation result is pass when the set value is 12 to 18, and the compensation result is fail when the set value is other than that. The inspection range is also set in the same way as in the first example.

[0066] In a first example, adjustment circuit 214 maintains the minimum value of the communication range if the compensation result is acceptable, and if the compensation result is unacceptable, increases the minimum value by 1. When the compensation result is acceptable, adjustment circuit 214 may decrease the minimum value by 1 if the difference between a set value based on the minimum and maximum values ​​(e.g., the average value of the minimum and maximum values) and the updated minimum value is smaller than a predetermined threshold.

[0067] Regarding the maximum value of the communication range, if the compensation result is acceptable, the adjustment circuit 214 maintains the maximum value, and if the compensation result is unacceptable, the adjustment circuit 214 decreases the maximum value by 1. Note that, when the compensation result is acceptable, the adjustment circuit 214 may increase the maximum value by 1 if the difference between a set value based on the minimum and maximum values ​​(e.g., an average value of the minimum and maximum values) and the updated maximum value is smaller than a predetermined threshold value.

[0068] For example, when the compensation results of both the minimum and maximum values ​​are fail, as in test 2-1, adjustment circuit 214 increases the minimum value from 12 to 13, decreases the maximum value from 18 to 17, and maintains the set value at 15. When the compensation result of the minimum value is fail and the compensation result of the maximum value is pass, as in test 2-2, adjustment circuit 214 increases the minimum value from 12 to 13, maintains the maximum value, and maintains the set value at 15. Note that adjustment circuit 214 may increase the set value from 15 to 16.

[0069] If the compensation results of both the minimum and maximum values ​​are pass, as in test 2-3, adjustment circuit 214 maintains the minimum value at 12, the maximum value at 18, and the set value at 15. If the compensation result of the minimum value is pass and the compensation result of the maximum value is fail, as in test 2-4, adjustment circuit 214 maintains the minimum value at 12, reduces the maximum value from 18 to 17, and reduces the set value from 15 to 14.

[0070] 8 is a timing chart for explaining an example of the operation of the automatic adjuster 210. The automatic adjuster 210 according to this embodiment dynamically adjusts the set value SET based on the compensation results in the blank periods T11 and T13. Here, it is assumed that the adjustment circuit 214 adjusts the set value in the same manner as in the first example above.

[0071] At timing t10, the communication range RNG is 10 to 20. At this time, the adjustment circuit 214 sets the set value SET to 15 (=(10+20) / 2), which is the average value of the minimum value MIN and the maximum value MAX.

[0072] At timing t11, the communication range RNG changes from 10-20 to 11-21. At timing t12, the valid period T10 ends and the blank period T11 begins, and the adjustment circuit 214 checks whether the compensation results for the minimum and maximum values ​​pass or fail. Specifically, when the blank period T11 begins, the adjustment circuit 214 sets the set value SET to 10. At this time, since the set value SET falls outside the communication range RNG, the compensation result is unsuccessful, and the communication error flag ERR becomes high (timing t13). The inspection circuit 212 updates the minimum value MIN of the inspection range to 11 in response to this compensation result (timing t14).

[0073] After that, the adjustment circuit 214 sets the set value SET to 20. At this time, since the set value SET is included in the communication range RNG, the compensation result is pass. In response to this compensation result, the inspection circuit 212 updates the maximum value MAX of the inspection range to 21 (timing t15).

[0074] The adjustment circuit 214 updates the set value SET based on the updated minimum value MIN and maximum value MAX. Specifically, the adjustment circuit 214 updates the set value SET to 16 (=(11+21) / 2), which is the average value of the minimum value MIN and the maximum value MAX.

[0075] At timing t16, when the blank period T11 ends and the valid period T12 starts, compensation according to the updated set value SET is applied to the first serial data D1S. In subsequent blank periods (for example, blank period T13), similarly to the blank period T11, the compensation results are inspected for each of the minimum value MIN and maximum value MAX of the inspection range, and the inspection range is updated according to the inspection results, and the set value SET is updated.

[0076] According to the automatic adjuster 210 of this embodiment, even if an error occurs in the compensation result during the blank periods T11 and T13, the result does not affect the serial communication. Therefore, according to the automatic adjuster 210 of this embodiment, the setting value of the compensation circuit 202 can be dynamically adjusted without affecting the serial communication, and the first serial data D1S can be more appropriately compensated.

[0077] 9 is a timing chart for explaining an example of the operation of automatic adjuster 210 to check the compensation result during the blank period. Check circuit 212 waits for a change in the set value based on counter CNTw (period Tw2 is, for example, about 1 μs). After waiting time Tw3 (for example, about 1 to 8 μs) has elapsed, check circuit 212 checks the compensation result during check time Tchk (for example, about 1 to 512 μs) based on counter CNTc. Check circuit 212 may be configured to be able to switch check time Tchk as appropriate.

[0078] 10 is a flowchart for explaining an example of the operation of second device 20 according to this embodiment. First, automatic adjuster 210 performs a startup inspection process (S100). As a result, a setting value is set in compensation circuit 202. Details of the startup inspection process will be described later with reference to FIG. 10. After the startup inspection process ends, second device 20 starts serial communication using the setting value set in S100 (S120).

[0079] Next, the adjustment circuit 214 judges whether or not the first serial data DS1 is in a blank period (S122). If it is judged that the first serial data DS1 is not in a blank period (S122: NO), the process of S122 is performed again.

[0080] If it is determined that the first serial data DS1 is in a blank period (S122: YES), the adjustment circuit 214 sets the setting value of the compensation circuit 202 to the minimum value of the inspection range (S124). Next, the compensation circuit 202 applies compensation to the first serial data DS1 according to the setting value (S126). Next, the inspection circuit 212 inspects the compensation result in S126, and updates the minimum value of the inspection range based on the inspection result (S128).

[0081] Next, the adjustment circuit 214 sets the setting value of the compensation circuit 202 to the maximum value of the inspection range (S130). Next, the compensation circuit 202 applies compensation according to the setting value to the first serial data DS1 (S132). Next, the inspection circuit 212 inspects the compensation result in S132, and updates the maximum value of the inspection range based on the inspection result (S134).

[0082] The adjustment circuit 214 adjusts the set value based on the minimum value updated in S128 and the maximum value updated in S134 (S136). The adjustment circuit 214 may set the set value to the average value of the updated minimum and maximum values. When the set value is adjusted, the compensation circuit 202 determines whether the blank period has ended (S138). If it is determined that the blank period has not ended (S138: NO), the process of S138 is performed again.

[0083] When it is determined that the blank period has ended (S138: YES), the compensation circuit 202 applies compensation to the first serial data DS1 according to the adjusted set value (S140). Next, the compensation circuit 202 determines whether or not the serial communication has ended (S142). When it is determined that the serial communication has not ended (S142: NO), the process returns to S122. On the other hand, when it is determined that the serial communication has ended (S142: YES), the process ends.

[0084] FIG. 11 is a timing chart for explaining the flow of the startup inspection process (S100) shown in FIG.

[0085] First, the adjustment circuit 214 sets the minimum value of the initial inspection range as a setting value in the compensation circuit 202 (S102). Next, the compensation circuit 202 performs compensation according to the setting value on the first serial data D1S (S104). Next, the inspection circuit 212 inspects the result of the compensation circuit 202 compensating for the first serial data D1S in S104 (S106). Next, the adjustment circuit 214 increases the setting value of the compensation circuit 202 by one (S108).

[0086] Next, the adjustment circuit 214 determines whether the start-up inspection is complete (S110). For example, the adjustment circuit 214 may determine that the compensation is complete if the set value exceeds the initial inspection range, and may determine that the compensation is not complete if the set value is within the initial inspection range. If it is determined that the start-up inspection is not complete (S110: NO), the processes of S104 to S110 are performed again.

[0087] When it is determined that the start-up inspection is completed (S110: YES), inspection circuit 212 determines the maximum and minimum values ​​of the communication range based on the inspection results repeatedly performed in S104 to S110, and sets the communication range as the inspection range (S112). Next, adjustment circuit 214 sets a setting value for compensation circuit 202 based on the maximum and minimum values ​​of the communication range determined in S112 (S114). For example, adjustment circuit 214 may set the setting value to the average value of the maximum and minimum values. When the setting value is set in compensation circuit 202 in S114, the start-up inspection process ends.

[0088] The configuration and operation of the communication system 1 according to this embodiment have been described above. The compensation circuit 202 included in the receiving device (second device 20) according to this embodiment applies compensation to the communication data (first serial data D1S) according to each of the first and second test values ​​included in the test range of the set value during the blank period. The test circuit 212 tests the compensation results according to each of the first and second test values ​​(minimum value of the test range) and the second test value (maximum value of the test range). The adjustment circuit 214 adjusts the set value so that the set value becomes a value between the first set value (minimum value of the test range after update) based on the compensation result according to the first test value and the second set value (maximum value of the test range after update) based on the compensation result according to the second test value during the valid period.

[0089] According to this configuration, since the set value of compensation circuit 202 can be dynamically adjusted while serial communication is being performed, even if the surrounding environmental conditions (such as temperature) change, it is possible to set the set value according to the change. As a result, even if the quality of the serial communication changes, it is possible to prevent the set value from going out of an appropriate range and to more appropriately compensate the communication data. Furthermore, since compensation according to each of the first and second test values ​​is performed during a blank period, even if an error occurs in the compensation result, the serial communication is not affected.

[0090] (supplement) Although the embodiments of the present disclosure have been described using specific terms, this description is merely an example to aid in understanding and does not limit the scope of the present disclosure or the claims, and the scope of the present invention is defined by the claims. In addition, not only the embodiments, but also embodiments, examples, and modified examples not described herein are included in the scope of the present invention.

[0091] (Additional Note) One aspect of the technology disclosed in this specification can be understood as follows.

[0092] (Item 1) an input pin for inputting communication data having alternating valid periods and blank periods; a compensation circuit that performs compensation on the communication data according to a set value; a check circuit that checks a compensation result by the compensation circuit according to the set value during the blank period; an adjustment circuit that adjusts the set value based on an inspection result of the compensation result by the inspection circuit; the compensation circuit performs compensation on the communication data in accordance with a first test value and a second test value included in a test range of the set value during the blank period; the inspection circuit inspects the compensation result in response to each of the first inspection value and the second inspection value; the adjustment circuit adjusts the setting value so that the setting value becomes a value between a first setting value based on the compensation result corresponding to the first inspection value and a second setting value based on the compensation result corresponding to the second inspection value during the valid period. Receiving device.

[0093] (Item 2) the compensation circuit performs compensation on the communication data in accordance with each of a plurality of inspection values ​​included in the initial inspection range of the set value; the inspection circuit inspects the compensation result corresponding to each of the plurality of inspection values, and sets, based on the inspection result, a communication range within the initial inspection range in which no error occurs in the compensation result, as the inspection range. Item 1. A receiving device according to item 1.

[0094] (Item 3) When the initial test range includes a plurality of communication ranges, the test circuit sets the widest range among the plurality of communication ranges as the test range. Item 2. A receiving device according to item 2.

[0095] (Item 4) the first test value is a minimum value of the test range; The second test value is the maximum value of the test range. The receiving device according to any one of items 1 to 3.

[0096] (Item 5) the inspection circuit updates the minimum value and the maximum value of the inspection range based on a compensation result by the compensation circuit corresponding to each of the first inspection value and the second inspection value. Item 5. A receiving device according to item 4.

[0097] (Item 6) the adjustment circuit adjusts the setting value so that the setting value becomes an average value of a minimum value of the updated inspection range and a maximum value of the updated inspection range during the valid period. Item 5. A receiving device according to item 5.

[0098] (Item 7) the inspection circuit inspects the compensation result based on an eye opening of the compensation result; The receiving device according to any one of items 1 to 6.

[0099] (Item 8) the compensation result is a result of the compensation circuit performing compensation according to the set value on the data of the blank period included in the communication data. The receiving device according to any one of items 1 to 7.

[0100] (Item 9) A receiving device according to any one of items 1 to 8, A transmitting device that transmits the communication data to the receiving device. Communication systems. [Explanation of symbols]

[0101] 1 communication system, 10 first device (transmitting device), 20 second device (receiving device), 102 driver, 106 parallel-serial converter, 206 serial-parallel converter, 202 compensation circuit, 210 automatic adjuster, 212 inspection circuit, 214 adjustment circuit.

Claims

1. an input pin for inputting communication data having alternating valid periods and blank periods; a compensation circuit that performs compensation on the communication data according to a set value; a check circuit that checks a compensation result by the compensation circuit according to the set value during the blank period; an adjustment circuit that adjusts the set value based on an inspection result of the compensation result by the inspection circuit; the compensation circuit performs compensation on the communication data in accordance with a first test value and a second test value included in a test range of the set value during the blank period; the inspection circuit inspects the compensation result in response to each of the first inspection value and the second inspection value; the adjustment circuit adjusts the setting value so that the setting value becomes a value between a first setting value based on the compensation result corresponding to the first inspection value and a second setting value based on the compensation result corresponding to the second inspection value during the valid period. Receiving device.

2. the compensation circuit performs compensation on the communication data in accordance with each of a plurality of inspection values ​​included in the initial inspection range of the set value; the inspection circuit inspects the compensation result corresponding to each of the plurality of inspection values, and sets, based on the inspection result, a communication range within the initial inspection range in which no error occurs in the compensation result, as the inspection range.

2. The receiving device according to claim 1.

3. When the initial test range includes a plurality of communication ranges, the test circuit sets the widest range among the plurality of communication ranges as the test range.

3. The receiving device according to claim 2.

4. the first test value is a minimum value of the test range; The second test value is a maximum value of the test range.

2. The receiving device according to claim 1.

5. the inspection circuit updates a minimum value and a maximum value of the inspection range based on a compensation result by the compensation circuit corresponding to each of the first inspection value and the second inspection value.

5. The receiving device according to claim 4.

6. the adjustment circuit adjusts the setting value so that the setting value becomes an average value of a minimum value of the updated inspection range and a maximum value of the updated inspection range during the valid period.

6. The receiving device according to claim 5.

7. the inspection circuit inspects the compensation result based on an eye opening of the compensation result; 2. The receiving device according to claim 1.

8. the compensation result is a result of the compensation circuit performing compensation according to the set value on the data of the blank period included in the communication data.

2. The receiving device according to claim 1.

9. A receiving device according to any one of claims 1 to 8, A transmitting device that transmits the communication data to the receiving device. Communication systems.

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