Data communication device

Abstract

This data communication device (1) comprises a temperature monitoring unit (2) and a control circuit unit (3). The control circuit unit (3) has: a count value calculation unit (30) that calculates a count value for the oscillation frequency of the temperature monitoring unit (2); and a temperature determination unit (31) that determines the temperature on the basis of the calculated result for the count value. The temperature monitoring unit (2) has: oscillation circuits (11, 12, 13) which are provided in at least two groups and in which two or more inverters are connected in an odd number of stages in each group; and counters (20) which are each connected to an output terminal of the final-stage inverter (10) in the respective oscillation circuit (11, 12, 13). The counters (20) are connected to the count value calculation unit (30), and the output of the final-stage inverter (10) in each oscillation circuit (11, 12, 13) is connected in a loop to the first-stage inverter (10) of the oscillation circuit (11, 12, 13).

Description

Data communication equipment

[0001] The present disclosure relates to data communication devices.

[0002] Semiconductor integrated circuits, which are components of data communication devices, may experience increased driving capabilities in low-temperature environments, for example, between -40 and 0°C, resulting in overshoot or ripple in the output waveform. To address this issue, it has been proposed to detect the temperature of the target semiconductor integrated circuit and control the target semiconductor integrated circuit in accordance with the detected temperature. For example, Patent Document 1 describes a technology for detecting temperature using a ring oscillator and controlling the output waveform. This technology compares the count value of the oscillation frequency corresponding to the temperature detected by the ring oscillator with a threshold value, and selects an optimal output waveform based on the comparison result.

[0003] JP 2009-267775 A

[0004] The conventional technology described in Patent Document 1 uses a ring oscillator, and therefore has a problem of generating a detected temperature error due to self-heating that depends on the oscillation frequency.

[0005] The present disclosure is intended to solve the above-mentioned problems, and aims to provide a data communication device that can suppress detected temperature errors caused by self-heating.

[0006] The data communication device according to the present disclosure comprises a temperature monitoring unit that monitors temperature changes based on the oscillation frequency, and a control circuit unit that controls the resistance value of a variable output resistor provided in the output section of a semiconductor integrated circuit, the control circuit unit having a count value calculation unit that calculates the count value of the oscillation frequency of the temperature monitoring unit, and a temperature determination unit that determines the temperature based on the calculation result of the count value, and at least two or more temperature monitoring units are provided, each having an oscillation circuit in which two or more inverters are connected in an odd number of stages, and a counter connected to the output terminal of the inverter in the final stage in the oscillation circuit, the counter being connected to the count value calculation unit, and the output of the inverter in the final stage in the oscillation circuit being connected in a loop with the inverter in the first stage of the oscillation circuit.

[0007] According to the present disclosure, the data communication device includes at least two oscillator circuits, each of which has two or more inverters connected in an odd number of stages, and a counter connected to the output terminal of the final-stage inverter in the oscillator circuit. The counter is connected to a count value calculation unit, and the output of the final-stage inverter in the oscillator circuit is connected in a loop with the first-stage inverter in the oscillator circuit. The data communication device according to the present disclosure can reduce detected temperature errors due to self-heating by determining the temperature based on the calculation result of the count value of the oscillation frequency.

[0008] It is a circuit diagram showing a configuration example of a data communication device according to embodiment 1. It is a circuit diagram showing a configuration example of a data communication device according to embodiment 2. It is a circuit diagram showing a configuration example of a data communication device according to embodiment 3. It is a diagram showing a control signal of a selector in embodiment 3.

[0009] Embodiment 1. Fig. 1 is a circuit diagram showing an example configuration of a data communication device 1 according to embodiment 1. In Fig. 1, the data communication device 1 monitors temperature based on the oscillation frequency and optimizes communication functions by adjusting the resistance value of a variable output resistor as necessary. The data communication device 1 includes a temperature monitoring unit 2 and a control circuit unit 3, and controls the output waveform of a data signal output unit 4 in response to temperature changes. The temperature monitoring unit 2 monitors temperature changes based on the oscillation frequency. The control circuit unit 3 controls the resistance value of a variable output resistor 41 provided in the output section of a semiconductor integrated circuit 40 included in the data signal output unit 4.

[0010] (Temperature Monitoring Unit) The temperature monitoring unit 2 monitors temperature changes based on the oscillation frequency. As shown in FIG. 1 , at least two temperature monitoring units 2 are provided, each including ring oscillation circuits 11, 12, and 13, each including two or more inverters 10 connected in an odd number of stages, and a counter 20 connected to the output terminal of the final-stage inverter 10 in the ring oscillation circuits 11, 12, and 13. The output terminal of the final-stage inverter 10 in at least one of the ring oscillation circuits 11, 12, and 13 is connected in a loop with the inverter 10. This allows the temperature monitoring unit 2 to include at least one ring oscillation circuit whose oscillation frequency changes in response to temperature changes. In the example of FIG. 1 , the output of the final-stage inverter 10 in each of the ring oscillation circuits 11, 12, and 13 is connected in a loop with the first-stage inverter 10 in each of the ring oscillation circuits 11, 12, and 13, respectively.

[0011] Counter 20 is provided in the subsequent stage of each of ring oscillation circuits 11, 12, and 13. Counter 20 counts the oscillation frequencies oscillated by each of ring oscillation circuits 11, 12, and 13, and outputs the count value of the oscillation frequencies. Counter 20 is connected to count value calculation unit 30 provided in control circuit unit 3. The count value of the oscillation frequencies counted by counter 20 is output to count value calculation unit 30.

[0012] The ring oscillator circuits 11, 12, and 13 are oscillator circuits in which an odd number of inverters 10, which are NOT gates, are connected in a loop. The inverters 10 invert the input signal. That is, when the input is "1," the output is "0," and when the input is "0," the output is "1." In the ring oscillator circuits 11, 12, and 13, the output of the last-stage inverter 10 is fed back to the input of the first-stage inverter 10, causing continuous inversion. For example, in the ring oscillator circuit 11 consisting of three inverters 10, the signal changes continuously from the initial state to "1," "0," "1," and so on. This change is repeated periodically over time, and therefore the circuit functions as an oscillator.

[0013] The oscillation frequency from the ring oscillation circuits 11, 12 and 13 depends on the propagation delay time of the inverter 10, that is, the time it takes for a signal to pass through the inverter 10. The shorter the propagation delay time, the higher the oscillation frequency.

[0014] Because the characteristics of the semiconductor integrated circuit 40 change with temperature, the propagation delay time of the inverter 10 also changes with temperature. Specifically, as temperature increases, the carrier mobility of the semiconductor decreases, and the propagation delay time of the inverter 10 tends to increase. This decreases the oscillation frequency of the ring oscillator circuits 11, 12, and 13. Conversely, as temperature decreases, the propagation delay time of the inverter 10 decreases, and the oscillation frequency of the ring oscillator circuits 11, 12, and 13 increases. The temperature monitoring unit 2 monitors temperature changes by using the ring oscillator circuits 11, 12, and 13 to oscillate at different locations or under different conditions and measuring the oscillation frequency. For example, the current temperature can be estimated by comparing the oscillation frequency at a reference temperature.

[0015] 1 shows a case where the temperature monitoring unit 2 includes ring oscillator circuits 11, 12, and 13, with the ring oscillator circuit 11 including three inverters 10, the ring oscillator circuit 12 including five inverters 10, and the ring oscillator circuit 13 including seven inverters 10. However, the temperature monitoring unit 2 may include at least two ring oscillator circuits, and each ring oscillator circuit may include an odd number of inverters 10. Furthermore, the multiple ring oscillator circuits may include ring oscillator circuits with the same number of inverters 10.

[0016] (Control Circuit Unit) The control circuit unit 3 calculates the count value of the oscillation frequency from the temperature monitoring unit 2 and determines the temperature based on the calculation result of the count value. As shown in Fig. 1, the control circuit unit 3 is configured with a count value calculation unit 30 and a temperature determination unit 31. The count value calculation unit 30 calculates the count value of the oscillation frequency from the temperature monitoring unit 2. The temperature determination unit 31 determines the temperature based on the calculation result of the count value.

[0017] The count value calculation unit 30 may calculate an average value of the count values ​​acquired from at least one or more counters 20 of the temperature monitoring unit 2, and output the calculated average value to the temperature determination unit 31. For example, when the count value calculation unit 30 acquires count values ​​from a plurality of counters 20, it calculates an average value of the count values ​​by adding up the acquired count values ​​and dividing the sum by a preset number of counters 20. By calculating the average value of the count values, even if an open or short circuit failure occurs in any of the plurality of inverters 10 provided in the temperature monitoring unit 2 and the count value becomes 0, a value corresponding to the count value of any of the oscillation frequencies can be output to the temperature determination unit 31, and temperature determination is possible.

[0018] The count value calculation unit 30 may calculate a median of the count values ​​acquired from at least one or more counters 20 of the temperature monitoring unit 2, and output the calculated median to the temperature determination unit 31. For example, when the count value calculation unit 30 acquires count values ​​from a plurality of counters 20, it calculates a median of the acquired count values ​​and outputs the median to the temperature determination unit 31. By calculating the median of the count values, even if an open or short circuit failure occurs in any of the plurality of inverters 10 provided in the temperature monitoring unit 2 and the count value becomes 0, a value corresponding to the count value of any of the oscillation frequencies can be output to the temperature determination unit 31, and temperature determination is possible.

[0019] The temperature determination unit 31 determines the temperature based on the calculation result (average value, median value, etc.) of the count value, and outputs a control signal corresponding to the determined temperature to the data signal output unit 4. For example, the temperature determination unit 31 may include a lower limit threshold X Ｌ and upper threshold X Ｈ As described above, the general tendency of a ring oscillator circuit with respect to environmental temperature is that as the temperature rises, the oscillation frequency of the ring oscillator circuit decreases and the count value decreases. Conversely, as the temperature drops, the oscillation frequency of the ring oscillator circuit increases and the count value increases. Therefore, the lower limit threshold X Ｌ and upper threshold X Ｈ is X Ｈ <X ＬThe temperature determination unit 31 determines the value X, which is the calculation result of the count value, and the lower limit threshold X Ｌ and upper threshold X Ｈ The temperature is determined based on the magnitude relationship between the temperature and the temperature.

[0020] (Data Signal Output Section) As shown in FIG. 1, the data signal output section 4 is configured to include a semiconductor integrated circuit 40 and a variable output resistor 41. The semiconductor integrated circuit 40 performs information processing on an input signal and outputs the processing result. The variable output resistor 41 is provided in the output section of the semiconductor integrated circuit 40, and its resistance value is switched in response to a control signal. When a control signal is input from the control circuit section 3, the variable output resistor 41 changes to a resistance in response to the control signal. This makes it possible to improve the waveform quality of the output signal from the data signal output section 4.

[0021] Next, the operation of the data communication device 1 will be described. First, it is assumed that the resistance value of the variable output resistor 41 is an initial value adjusted during operation at room temperature. The temperature determination unit 31 calculates the value X, which is the calculation result of the count value, and the lower limit threshold X Ｌ The magnitude relationship between Ｌ <X, it is determined that the operation is at a low temperature. In this case, the temperature determination unit 31 controls the variable output resistor 41 to increase its resistance value, thereby suppressing overshoot of the output waveform of the data signal output unit 4.

[0022] The temperature determination unit 31 calculates the count value X and the upper threshold X Ｈ The magnitude relationship between X and X is Ｈ In this case, the temperature determining unit 31 controls the variable output resistor 41 to decrease its resistance value, thereby suppressing distortion of the output waveform of the data signal output unit 4.

[0023] The temperature determination unit 31 calculates the count value X and the lower threshold X Ｌ and upper threshold X Ｈ The magnitude relationship between Ｈ <X<X Ｌ In this case, the temperature determining unit 31 does not perform control to change the resistance of the variable output resistor 41, for example, by leaving the resistance value of the variable output resistor 41 at its initial value.

[0024] As described above, the data communication device 1 according to the first embodiment includes a temperature monitoring unit 2 and a control circuit unit 3. The control circuit unit 3 includes a count value calculation unit 30 that calculates the count value of the oscillation frequency of the temperature monitoring unit 2, and a temperature determination unit 31 that determines the temperature based on the calculation result of the count value. At least two temperature monitoring units 2 are provided, each including ring oscillation circuits 11, 12, and 13, each having two or more inverters 10 connected in an odd number of stages, and a counter 20 connected to the output terminal of the final-stage inverter 10 in the ring oscillation circuits 11, 12, and 13. The counter 20 is connected to the count value calculation unit 30. The output of the final-stage inverter 10 in the ring oscillation circuits 11, 12, and 13 is connected in a loop with the first-stage inverter 10 in the ring oscillation circuits 11, 12, and 13. This allows the data communication device 1 to determine the temperature based on the calculation result of the count values ​​of multiple oscillation frequencies, thereby suppressing detected temperature errors due to self-heating. In particular, since the low-temperature operating state can be accurately determined, it is possible to suppress overshooting of the output waveform of the data signal output unit 4 that occurs at low temperatures. Furthermore, in the data communication device 1 according to the first embodiment, the temperature monitoring unit 2 and the control circuit unit 3 may be configured in the same semiconductor integrated circuit. For example, by configuring the data communication device 1 using an FPGA, it is possible to reduce the circuit space. Furthermore, by configuring the data communication device 1 according to the first embodiment as the same semiconductor integrated circuit, it is possible to monitor the temperature using the same process, and it is possible to determine the operating temperature with higher accuracy.

[0025] In the data communication device 1 according to the first embodiment, the output of at least one inverter 10 in the final stage of each of the ring oscillation circuits 11, 12, and 13 is connected in a loop with the inverter 10. This allows the temperature monitoring unit 2 to include at least one ring oscillation circuit whose oscillation frequency changes in response to temperature changes.

[0026] In the data communication device 1 according to the first embodiment, the count value calculation unit 30 calculates the average value of the count values ​​acquired from at least one counter 20 of the temperature monitoring unit 2, and outputs the calculated average value to the temperature determination unit 31. Even if an open or short circuit failure occurs in any of the multiple inverters 10 provided in the temperature monitoring unit 2, causing the count value to become 0, a value corresponding to the count value of any of the oscillation frequencies can be output to the temperature determination unit 31, making it possible to perform temperature determination.

[0027] In the data communication device 1 according to the first embodiment, the count value calculation unit 30 calculates the median of the count values ​​acquired from at least one counter 20 of the temperature monitoring unit 2, and outputs the calculated median value to the temperature determination unit 31. Even if an open or short circuit fault occurs in any of the multiple inverters 10 provided in the temperature monitoring unit 2, causing the count value to become 0, a value corresponding to the count value of any of the oscillation frequencies can be output to the temperature determination unit 31, making it possible to perform temperature determination.

[0028] Second Embodiment A data communication device according to a second embodiment includes a selection circuit unit that connects the output of an inverter selected from the output terminal of the final-stage inverter to a loop with the first-stage inverter of the ring oscillation circuit.

[0029] 2 is a circuit diagram showing an example configuration of a data communication device 1A according to a second embodiment. In FIG. 2, the data communication device 1A optimizes communication functions by monitoring temperature based on the oscillation frequency and adjusting the resistance value of a variable output resistor as necessary. The data communication device 1A includes a temperature monitoring unit 2A and a control circuit 3, and controls the output waveform of a data signal output unit 4 in response to temperature changes. The temperature monitoring unit 2A monitors temperature changes based on the oscillation frequency. The control circuit 3 controls the resistance value of a variable output resistor 41 provided in the output section of a semiconductor integrated circuit 40 included in the data signal output unit 4.

[0030] (Temperature Monitoring Unit) The temperature monitoring unit 2A includes a ring oscillator circuit 14 in which a plurality of inverters 10 are connected in a tournament configuration, and an inverter 10 at the end (final stage) of the tournament, selected by a selection circuit unit 50, is connected in a loop with the inverter 10 at the highest (first stage) of the tournament. In the tournament configuration of inverters 10, as shown in FIG. 2 , the output of the highest inverter 10 branches to the inputs of two inverters 10 in the second stage, and the output of the second stage inverter 10 branches to the inputs of four inverters 10 in the final stage, and the outputs of the four inverters 10 in the final stage are connected to the counter 20 and the selection circuit unit 50. Note that in the temperature monitoring unit 2A, the plurality of inverters 10 may be connected in a tree configuration.

[0031] The temperature monitoring unit 2A includes a plurality of inverters 10 connected in a tournament configuration, a counter 20 connected to the output of the final-stage inverter 10, a selection circuit unit 50, and a selection control circuit unit 51. Of the plurality of inverters 10 connected in a tournament configuration, the inverter 10 in the final stage of the tournament selected by the selection circuit unit 50 is connected in a loop with the inverter 10 in the first stage of the tournament. This allows the data communication device 1A to include a temperature monitoring unit 2A having one ring oscillator circuit whose oscillation frequency changes in response to temperature changes.

[0032] In the ring oscillation circuit 14, a counter 20 is connected to each output of the inverters 10 in the final stage of the tournament. The oscillation frequencies output from the inverters 10 in the final stage are counted by the counter 20. These count values ​​are output to the control circuit unit 3. The loop of the ring oscillation circuit used in the temperature monitoring unit 2A is selected by the selection circuit unit 50.

[0033] The selection circuit unit 50 is controlled by a selection control circuit unit 51. The selection control circuit unit 51 is connected to the selection circuit unit 50 and the count value calculation unit 30 provided in the control circuit unit 3. In the data communication device 1A, the output of the final-stage inverter 10 in the ring oscillation circuit 14 is connected to at least one inverter 10 in a loop. This allows the temperature monitoring unit 2A to include one ring oscillation circuit whose oscillation frequency changes in response to temperature changes.

[0034] The selection circuit unit 50 selects one inverter 10 from the multiple inverters 10 in the final stage in response to an instruction from the selection control circuit unit 51, and outputs a signal from the selected inverter 10 to the inverters 10 in the first stage of the tournament, thereby forming a loop connection as a ring oscillator circuit. Even if a fault such as an open circuit or short circuit occurs in one of the multiple inverters 10 and the count value of the oscillation frequency cannot be correctly obtained, the count value calculation unit 30 instructs the selection control circuit unit 51, and the selection circuit unit 50 selects a loop that does not include the faulty inverter 10, thereby allowing the temperature determination unit 31 to continue temperature determination.

[0035] The inverters 10 constituting the ring oscillation circuit 14 may be connected in a tournament configuration or a tree configuration, with at least one inverter 10 connected to each other, and the number of inverters 10 constituting the ring oscillation circuit 14 is free. In other words, the number of counters 20 is also free.

[0036] (Control Circuit Unit) The control circuit unit 3 calculates the count value of the oscillation frequency of the temperature monitoring unit 2A and determines the temperature based on the calculation result of the count value. As shown in Fig. 2, the control circuit unit 3 is configured with a count value calculation unit 30 and a temperature determination unit 31. The count value calculation unit 30 calculates the count value of the oscillation frequency from the temperature monitoring unit 2. The temperature determination unit 31 determines the temperature based on the calculation result of the count value.

[0037] The count value calculation unit 30 may calculate an average value of count values ​​acquired from a plurality of counters 20 connected to each of a plurality of inverters 10 in the final stage of the tournament, and output the calculated average value to the temperature determination unit 31. For example, when the count value calculation unit 30 acquires count values ​​from a plurality of counters 20, it calculates an average value of the count values ​​by adding up the acquired count values ​​and dividing the sum by a predetermined number of counters 20. By calculating the average value of the count values, even if an open or short circuit failure occurs in any of the plurality of inverters 10 included in the temperature monitoring unit 2A and the count value becomes 0, a value corresponding to the count value of any of the oscillation frequencies can be output to the temperature determination unit 31, and temperature determination is possible.

[0038] The count value calculation unit 30 may calculate a median of count values ​​acquired from the multiple counters 20 connected to each of the multiple inverters 10 in the final stage of the tournament, and output the calculated median to the temperature determination unit 31. For example, when the count value calculation unit 30 acquires count values ​​from the multiple counters 20, it calculates a median of the acquired count values ​​and outputs the median to the temperature determination unit 31. By calculating the median of the count values, even if an open or short circuit failure occurs in one of the multiple inverters 10 included in the temperature monitoring unit 2A and the count value becomes 0, a value corresponding to the count value of one of the oscillation frequencies can be output to the temperature determination unit 31, and temperature determination is possible.

[0039] As in the first embodiment, the temperature determination unit 31 determines the temperature based on the calculation result (average value, median value, etc.) of the count value, and outputs a control signal corresponding to the determined temperature to the data signal output unit 4. For example, the temperature determination unit 31 may include a lower limit threshold X Ｌ and upper threshold X Ｈ As described above, the general tendency of a ring oscillator circuit with respect to environmental temperature is that as the temperature rises, the oscillation frequency of the ring oscillator circuit decreases and the count value decreases. Conversely, as the temperature drops, the oscillation frequency of the ring oscillator circuit increases and the count value increases. Therefore, the lower limit threshold X Ｌ and upper threshold X Ｈ is XＨ <X Ｌ The temperature determination unit 31 determines the value X, which is the calculation result of the count value, and the lower limit threshold X Ｌ and upper threshold X Ｈ The temperature is determined based on the magnitude relationship between the temperature and the temperature.

[0040] (Data Signal Output Section) As shown in FIG. 2, the data signal output section 4 is configured to include a semiconductor integrated circuit 40 and a variable output resistor 41. The semiconductor integrated circuit 40 performs information processing on an input signal and outputs the processing result. The variable output resistor 41 is provided in the output section of the semiconductor integrated circuit 40, and its resistance value is switched in response to a control signal. When a control signal is input from the control circuit section 3, the variable output resistor 41 changes to a resistance in response to the control signal. This makes it possible to improve the waveform quality of the output signal from the data signal output section 4.

[0041] Next, the operation of the data communication device 1A will be described. First, the resistance value of the variable output resistor 41 is assumed to be an initial value adjusted during operation at room temperature. The temperature determination unit 31 calculates the value X, which is the calculation result of the count value, and the lower limit threshold X Ｌ The magnitude relationship between Ｌ <X, it is determined that the operation is at a low temperature. In this case, the temperature determination unit 31 controls the variable output resistor 41 to increase its resistance value, thereby suppressing overshoot of the output waveform of the data signal output unit 4.

[0042] The temperature determination unit 31 calculates the count value X and the upper threshold X Ｈ The magnitude relationship between X and X is Ｈ In this case, the temperature determining unit 31 controls the variable output resistor 41 to decrease its resistance value, thereby suppressing distortion of the output waveform of the data signal output unit 4.

[0043] The temperature determination unit 31 calculates the count value X and the lower threshold X Ｌ and upper threshold X Ｈ The magnitude relationship between Ｈ <X<X ＬIn this case, the temperature determining unit 31 does not perform control to change the resistance of the variable output resistor 41, for example, by leaving the resistance value of the variable output resistor 41 at its initial value.

[0044] The data communication device 1A according to the second embodiment may perform temperature determination using a plurality of temperature monitoring units 2A. Providing a plurality of temperature monitoring units 2A improves the accuracy of temperature determination and also makes it possible to deal with a wide range of failure modes (particularly initial stage failures) of the inverter 10 that constitutes the ring oscillation circuit 14.

[0045] As described above, in the data communication device 1A according to the second embodiment, for example, by connecting multiple inverters 10 in a tournament configuration, the output of at least one final-stage inverter 10 in the ring oscillation circuit 14 is connected in a loop with the inverter 10. This allows the temperature monitoring unit 2A to include at least one ring oscillation circuit whose oscillation frequency changes in response to temperature changes. In particular, it is possible to obtain multiple count values ​​with a small number of inverters 10. Furthermore, since the low-temperature operating state can be accurately determined, it is possible to suppress overshooting of the output waveform of the data signal output unit 4 that occurs at low temperatures. Furthermore, in the data communication device 1A, the temperature monitoring unit 2A and the control circuit unit 3 may be configured on the same semiconductor integrated circuit. For example, configuring the data communication device 1A using an FPGA can reduce circuit space. Furthermore, configuring the data communication device 1A as the same semiconductor integrated circuit allows temperature monitoring using the same process, resulting in more accurate determination of the operating temperature.

[0046] The data communication device 1A according to the second embodiment includes a selection circuit unit 50 that connects the output of an inverter 10 selected from the output terminals of the inverters 10 in the final stages of the ring oscillation circuits 11, 12, and 13 to the loop with the inverters 10 in the first stages of the ring oscillation circuits 11, 12, and 13. This allows the data communication device 1A to include a temperature monitoring unit 2A that has one ring oscillation circuit whose oscillation frequency changes in response to temperature changes.

[0047] Third Embodiment A data communication device according to a third embodiment includes an oscillation switching unit that switches the number of inverter stages in a ring oscillation circuit made up of multiple inverter stages.

[0048] 3 is a circuit diagram showing an example configuration of a data communication device 1B according to a third embodiment. In FIG. 3, the data communication device 1B optimizes communication functions by monitoring temperature based on the oscillation frequency and adjusting the resistance value of a variable output resistor as necessary. The data communication device 1B includes a temperature monitoring unit 2B and a control circuit 3, and controls the output waveform of a data signal output unit 4 in response to temperature changes. The temperature monitoring unit 2B monitors temperature changes based on the oscillation frequency. The control circuit 3 controls the resistance value of a variable output resistor 41 provided in the output section of a semiconductor integrated circuit 40 included in the data signal output unit 4.

[0049] (Temperature Monitoring Unit) The temperature monitoring unit 2B includes a ring oscillation circuit 15, a selection circuit unit 50, and a selection control circuit unit 51. The ring oscillation circuit 15 includes a plurality of inverters 10 and a selector 16. In the ring oscillation circuit 15, a first unit in which a plurality of inverters 10 are connected in series is connected to a second unit in which a plurality of inverters 10 are connected in a tournament configuration via the selector 16. In the second unit connected in a tournament configuration, the output of the inverter 10 selected by the selection circuit unit 50 from the inverters 10 at the end (final stage) of the tournament is connected to the input of the first-stage inverter 10 of the first unit in which a plurality of inverters 10 are connected in series. Note that the ring oscillation circuit 15 may include a unit in which a plurality of inverters 10 are connected in a tree configuration as the second unit, instead of a unit connected in a tournament configuration.

[0050] The inverters 10 that make up the ring oscillator circuit 15 are configured in an odd number of stages, and may be configured as a loop of three or more stages of inverters 10. The inverters 10 that make up the second unit connected in a tournament configuration are connected to at least one inverter 10, and the number of inverters 10 is arbitrary. This allows for the number of counters 20 to be arbitrary as well.

[0051] The selector 16 can change the number of stages of the inverter 10 by switching the connection between the first unit and the second unit. The temperature monitoring unit 2B connects the first unit and the second unit in a loop. This allows the data communication device 1B to be equipped with a temperature monitoring unit 2B that has one ring oscillator circuit whose oscillation frequency changes in response to temperature changes.

[0052] In the ring oscillation circuit 15, a counter 20 is connected to each output of the inverters 10 in the final stage of the second unit. The oscillation frequencies output from the inverters 10 in the final stage are counted by the counter 20. These count values ​​are output to the control circuit unit 3. The loop of the ring oscillation circuit used in the temperature monitoring unit 2B is selected by the selection circuit unit 50.

[0053] (Control Circuit Unit) The control circuit unit 3 calculates the count value of the oscillation frequency of the temperature monitoring unit 2B and determines the temperature based on the calculation result of the count value. As shown in Fig. 3, the control circuit unit 3 includes a count value calculation unit 30, a temperature determination unit 31, and an oscillation switching unit 32. The count value calculation unit 30 calculates the count value of the oscillation frequency from the temperature monitoring unit 2. The temperature determination unit 31 determines the temperature based on the calculation result of the count value.

[0054] The oscillation switching unit 32 switches the number of stages of the inverters 10 in the ring oscillation circuit 15. For example, the oscillation switching unit 32 controls the operation of the selector 16 by outputting a control signal En_a or En_b to the selector 16. FIG. 4 is a diagram showing the control signals En_a and En_b of the selector 16 in the third embodiment. As shown in FIG. 4, the control signals En_a and En_b for the selector 16 are determined so that the range of the oscillation frequency (count value) that the ring oscillation circuit 15 can take is limited depending on the temperature.

[0055] A predetermined temperature X ＳIf the temperature is equal to or less than the temperature X, the oscillation switching unit 32 sends a control signal En_a to the selector 16. The selector 16 selects a loop connection with a smaller number of stages in the ring oscillation circuit 15, and controls the ring oscillation circuit 15 to limit the lower limit range of the count value that can be taken at high temperatures. Ｓ If this is the case, the oscillation switching unit 32 sends a control signal En_b to the selector 16. The selector 16 selects a loop connection with a larger number of stages in the ring oscillation circuit 15, and performs control to suppress the upper limit range of the count value that the ring oscillation circuit 15 can take at low temperatures.

[0056] The count value calculation unit 30 may calculate an average value of count values ​​acquired from a plurality of counters 20 connected to each of a plurality of inverters 10 in the final stage of the tournament, and output the calculated average value to the temperature determination unit 31. For example, when the count value calculation unit 30 acquires count values ​​from a plurality of counters 20, it calculates an average value of the count values ​​by adding up the acquired count values ​​and dividing the sum by a predetermined number of counters 20. By calculating the average value of the count values, even if an open or short circuit occurs in one of the plurality of inverters 10 included in the temperature monitoring unit 2B and the count value becomes 0, a value corresponding to the count value of any of the oscillation frequencies can be output to the temperature determination unit 31, and temperature determination is possible.

[0057] The count value calculation unit 30 may calculate a median of count values ​​acquired from the multiple counters 20 connected to each of the multiple inverters 10 in the final stage of the tournament, and output the calculated median to the temperature determination unit 31. For example, when the count value calculation unit 30 acquires count values ​​from the multiple counters 20, it calculates a median of the acquired count values ​​and outputs the median to the temperature determination unit 31. By calculating the median of the count values, even if an open or short circuit failure occurs in one of the multiple inverters 10 included in the temperature monitoring unit 2B and the count value becomes 0, a value corresponding to the count value of any of the oscillation frequencies can be output to the temperature determination unit 31, and temperature determination is possible.

[0058] As in the first embodiment, the temperature determination unit 31 determines the temperature based on the calculation result (average value, median value, etc.) of the count value, and outputs a control signal corresponding to the determined temperature to the data signal output unit 4. For example, the temperature determination unit 31 may include a lower limit threshold X Ｌ and upper threshold X Ｈ As described above, the general tendency of a ring oscillator circuit with respect to environmental temperature is that as the temperature rises, the oscillation frequency of the ring oscillator circuit decreases and the count value decreases. Conversely, as the temperature drops, the oscillation frequency of the ring oscillator circuit increases and the count value increases. Therefore, the lower limit threshold X Ｌ and upper threshold X Ｈ is X Ｈ <X Ｌ The temperature determination unit 31 determines the value X, which is the calculation result of the count value, and the lower limit threshold X Ｌ and upper threshold X Ｈ The temperature is determined based on the magnitude relationship between the temperature and the temperature.

[0059] (Data Signal Output Section) As shown in FIG. 3, the data signal output section 4 is configured to include a semiconductor integrated circuit 40 and a variable output resistor 41. The semiconductor integrated circuit 40 performs information processing on an input signal and outputs the processing result. The variable output resistor 41 is provided in the output section of the semiconductor integrated circuit 40, and its resistance value is switched in response to a control signal. When a control signal is input from the control circuit section 3, the variable output resistor 41 changes to a resistance in response to the control signal. This makes it possible to improve the waveform quality of the output signal from the data signal output section 4.

[0060] Next, the operation of the data communication device 1B will be described. First, the resistance value of the variable output resistor 41 is assumed to be the initial value adjusted during operation at room temperature. The temperature determination unit 31 calculates the value X, which is the calculation result of the count value, and the lower limit threshold X Ｌ The magnitude relationship between Ｌ <X, it is determined that the operation is at a low temperature. In this case, the temperature determination unit 31 controls the variable output resistor 41 to increase its resistance value, thereby suppressing overshoot of the output waveform of the data signal output unit 4.

[0061] The temperature determination unit 31 calculates the count value X and the upper threshold X Ｈ The magnitude relationship between X and X is Ｈ In this case, the temperature determining unit 31 controls the variable output resistor 41 to decrease its resistance value, thereby suppressing distortion of the output waveform of the data signal output unit 4.

[0062] The temperature determination unit 31 calculates the count value X and the lower threshold X Ｌ and upper threshold X Ｈ The magnitude relationship between Ｈ <X<X Ｌ In this case, the temperature determining unit 31 does not perform control to change the resistance of the variable output resistor 41, for example, by leaving the resistance value of the variable output resistor 41 at its initial value.

[0063] The data communication device 1A according to the second embodiment may perform temperature determination using a plurality of temperature monitoring units 2A. Providing a plurality of temperature monitoring units 2A improves the accuracy of temperature determination and also makes it possible to deal with a wide range of failure modes (particularly initial stage failures) of the inverter 10 that constitutes the ring oscillation circuit 14.

[0064] The threshold value X of the count value set by the temperature determination unit 31 Ｌ and X Ｈ and the temperature X set by the oscillation switching unit 32 Ｓ is X Ｈ <X Ｓ <X Ｌ The relationship is as follows: Count value X vs. threshold value X Ｌ , X Ｈ and X Ｓ The variable output resistor 41 of the data signal output unit 4 is set to an initial value adjusted during operation at room temperature.

[0065] X Ｓ <X Ｌ <X, the temperature determination unit 31 determines that the operation is at a low temperature, and performs control to increase the resistance value of the variable output resistor 41 of the data signal output unit 4. This makes it possible to make adjustments to suppress overshoot in the output waveform.

[0066] X<XＨ <X Ｓ If so, the temperature determination unit 31 determines that the operation is at a high temperature, and performs control to decrease the resistance value of the variable output resistor 41 of the data signal output unit 4. This makes it possible to make adjustments to suppress distortion of the output waveform.

[0067] X Ｈ <X<X Ｌ If X is the case, the temperature determination unit 31 determines that the operation is at room temperature, and the resistance value of the variable output resistor 41 of the data signal output unit 4 remains at the initial value without performing any control. Ｓ <X<X Ｌ , the temperature determination unit 31 determines that the operation is at room temperature, but the oscillation switching unit 32 transmits the control signal En_a to the selector 16. Ｈ <X<X Ｓ If so, the temperature determination unit 31 determines that the operation is at room temperature, but the oscillation switching unit 32 transmits the control signal En_b to the selector 16 .

[0068] The data communication device 1B according to the third embodiment may perform temperature determination using a plurality of temperature monitoring units 2B. Providing a plurality of temperature monitoring units 2B improves the accuracy of temperature determination and also makes it possible to deal with a wide range of failure modes (particularly initial stage failures) of the inverter 10 that constitutes the ring oscillation circuit 15.

[0069] As described above, the data communication device 1B according to the third embodiment includes an oscillation switching unit 32 that switches the number of inverters 10. This allows multiple count values ​​to be acquired using a small number of inverters 10, and furthermore, it is possible to suppress fluctuations in the oscillation frequency (count value) of the ring oscillator circuit that occur depending on temperature. In particular, it is possible to accurately determine the low-temperature operating state and suppress overshoots in the data signal output waveform that occur at low temperatures. Furthermore, the data communication device 1B may have the temperature monitoring unit 2B and control circuit unit 3 configured on the same semiconductor integrated circuit. For example, configuring the data communication device 1B using an FPGA can reduce circuit space. Furthermore, configuring the data communication device 1B as the same semiconductor integrated circuit allows temperature monitoring using the same process, resulting in more accurate determination of the operating temperature.

[0070] Various aspects of the present disclosure are summarized below as appendices.

[0071] (Supplementary Note 1) A data communication device comprising: a temperature monitoring unit that monitors temperature changes based on an oscillation frequency; and a control circuit unit that controls the resistance value of a variable output resistor provided in an output unit of a semiconductor integrated circuit, wherein the control circuit unit has a count value calculation unit that calculates a count value of the oscillation frequency of the temperature monitoring unit, and a temperature determination unit that determines the temperature based on the calculation result of the count value, wherein at least two or more temperature monitoring units are provided, each unit having an oscillation circuit in which two or more inverters are connected in an odd number of stages, and a counter connected to the output terminal of the inverter in the final stage in the oscillation circuit, wherein the counter is connected to the count value calculation unit, and the output of the inverter in the final stage in the oscillation circuit is connected in a loop with the inverter in the first stage of the oscillation circuit. (Supplementary Note 2) The data communication device according to Supplementary Note 1, wherein the output of the inverter in the final stage in the oscillation circuit is connected in a loop with the inverter in at least one or more stages. (Supplementary Note 3) The data communication device according to Supplementary Note 1 or Supplementary Note 2, further comprising a selection circuit that connects the output of an inverter selected from the output terminals of the inverters in the final stages of the plurality of oscillation circuits to the inverter in the first stage of the oscillation circuit in a loop. (Supplementary Note 4) The data communication device according to any one of Supplementary Note 1 to Supplementary Note 3, further comprising: the count value calculation unit calculates an average value of count values ​​acquired from at least one counter of the temperature monitoring units, and outputs the calculated average value to the temperature determination unit. (Supplementary Note 5) The data communication device according to any one of Supplementary Note 1 to Supplementary Note 4, further comprising: the count value calculation unit calculates a median value of count values ​​acquired from at least one counter of the temperature monitoring units, and outputs the calculated median value to the temperature determination unit. (Supplementary Note 6) The data communication device according to any one of Supplementary Note 1 to Supplementary Note 5, further comprising: an oscillation switching unit that switches the number of stages of the inverter.

[0072] It is possible to combine the embodiments, modify any of the components of the embodiments, or omit any of the components of the embodiments.

[0073] A data communication device according to the present disclosure can be used, for example, as a data communication device configured using a semiconductor integrated circuit.

[0074] 1, 1A, 1B Data communication device, 2, 2A, 2B Temperature monitoring unit, 3 Control circuit unit, 4 Data signal output unit, 10 Inverter, 11 to 15 Ring oscillation circuit, 16 Selector, 20 Counter, 30 Count value calculation unit, 31 Temperature determination unit, 32 Oscillation switching unit, 40 Semiconductor integrated circuit, 41 Variable output resistor, 50 Selection circuit unit, 51 Selection control circuit unit.

Claims

1. A data communication device comprising: a temperature monitoring unit that monitors temperature changes based on oscillation frequency; and a control circuit unit that controls the resistance value of a variable output resistor provided in the output unit of a semiconductor integrated circuit, wherein the control circuit unit has a count value calculation unit that calculates a count value of the oscillation frequency of the temperature monitoring unit, and a temperature determination unit that determines the temperature based on the count value calculation result, and wherein at least two or more temperature monitoring units are provided, each unit having an oscillation circuit in which two or more inverters are connected in an odd number of stages, and a counter connected to the output terminal of the inverter in the final stage of the oscillation circuit, and the counter is connected to the count value calculation unit, and the output of the inverter in the final stage of the oscillation circuit is connected in a loop with the inverter in the first stage of the oscillation circuit.

2. The data communication device according to claim 1, wherein the output of the inverter in the final stage of the oscillation circuit is connected to at least one of the inverters in a loop.

3. A data communication device according to claim 1 or claim 2, characterized in that it comprises a selection circuit section which connects the output of an inverter selected from the output terminals of the inverters in the final stages of a plurality of said oscillation circuits to the inverter in the first stage of said oscillation circuit in a loop.

4. A data communication device according to any one of claims 1 to 3, characterized in that the count value calculation unit calculates the average value of the count values ​​acquired from the counters of at least one of the temperature monitoring units, and outputs the calculated average value to the temperature determination unit.

5. A data communication device according to any one of claims 1 to 4, characterized in that the count value calculation unit calculates the median of the count values ​​acquired from at least one of the counters of the temperature monitoring unit, and outputs the calculated median to the temperature determination unit.

6. The data communication device according to any one of claims 1 to 5, further comprising an oscillation switching unit that switches the number of stages of the inverter.

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