JPH10224423A - Bus transmission controller in electronic control circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a bus width between the output device and the input device in the bus transmission controller in a electronic control circuit. SOLUTION: The bus transmission controller in the electronic control circuit that sends a digital signal outputted from an output device 40 to an input device 50 between the output device 40 and the input device 50 receiving the digital signal is provided with a D/A converter 10 that converts the digital signal outputted from the output device 40 into an analog signal, an A/D converter 20 that converts the analog signal into a digital signal again and gives it to the input device 50, and an analog signal transmission line 30 that sends the analog signal converted by the D/A converter 10 to the A/D converter 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bus transmission control device for controlling data transmission of a bus in an electronic control circuit such as an electronic computer (for example, a computer).

[0002]

2. Description of the Related Art Generally, in an electronic control circuit, digital signals are transmitted using a bus. Specifically, for example, as shown in FIG. 7, a bus having a required bus width (here, n lines) is provided between an output device for outputting a digital signal and an input device for receiving a digital signal. By connecting and transmitting a signal of a high level or a low level to each line of the bus, a binary value is represented, and transmission of a digital signal from an output device to an input device is realized. In this case, since the bus width for n lines is used,
It is possible to simultaneously transmit 2 ⁿ types of digital signals, that is, n-bit digital signals.

[0003]

However, in the electronic control circuit having the above configuration, a bus width of n lines is required to simultaneously transmit n-bit digital signals. For this reason, in this electronic control circuit, the number of bus drivers is increased, and the output device and the input device are integrated circuit (IC) or LSI (Large Scale).
In the case of an integrated circuit, there is a problem that the number of pins needs to be increased, or the amount of hardware constituting the circuit increases and the number of wiring patterns on the substrate increases.

Accordingly, an object of the present invention is to provide a bus transmission control device in an electronic control circuit capable of reducing the bus width between an output device and an input device as compared with the related art.

[0005]

SUMMARY OF THE INVENTION The present invention has been devised to achieve the above object, and is provided between an output device for outputting a digital signal and an input device for inputting the digital signal. A bus transmission control device in an electronic control circuit for transmitting a digital signal output from the output device to the input device, a D / A converter for receiving the digital signal output from the output device and converting the digital signal into an analog signal; A / D which converts the analog signal converted by the D / A converter into a digital signal again and sends it to the input device.
A D converter and an analog signal transmission line for transmitting an analog signal converted by the D / A converter to the A / D converter are provided.

According to the bus transmission control device having the above configuration, when the output device outputs a digital signal, the D / A converter receives the digital signal and converts it into an analog signal. D / A
When the converter converts the digital signal into an analog signal, the analog signal transmission path transmits the analog signal to the A / D converter. Then, the A / D converter receives the analog signal from the analog signal transmission line, converts the analog signal into a digital signal again, and sends out the converted digital signal to the input device. Therefore, in this bus transmission control device, even if the output device outputs an n-bit digital signal, for example,
Since the / A converter converts this to an analog signal, D /
Between the A converter and the A / D converter, transmission can be performed only by an analog signal transmission line for one line.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A bus transmission control device in an electronic control circuit according to the present invention will be described below with reference to the drawings.

[First Embodiment] Here, a first embodiment will be described.
A bus transmission control device according to the described invention will be described. The bus transmission control device of the present embodiment is provided between an A device 40 and a B device 50 as shown in FIG. Here, first, prior to the description of the bus transmission control device, the A device 40 and the B device 50 will be described.

The A device 40 is composed of, for example, an IC or LSI, has an output bus (or output pin) 40a having a bus width of n lines, and outputs an n-bit digital signal from the output bus 40a. It is. B device 50
Is composed of an IC or an LSI like the A device 40.
Input bus (or input pin) 5 with a bus width of n lines
0a, and an n-bit digital signal is input to the input bus 50a. The A device 40 and B
Each of the devices 50 operates in synchronization with a clock signal (hereinafter, referred to as CLK) from an external device.

The bus transmission control device provided between the A device 40 and the B device 50 has a D / A converter (Digi
tal to Analog Converter; hereinafter abbreviated as DAC) 10
, An A / D converter (Analog to Digital Converter; hereinafter abbreviated as ADC) 20 and an analog signal transmission line 30.

The DAC 10 is connected to the output bus 40 of the A device 40.
a, which receives an n-bit digital signal output from the output bus 40a and converts it into an analog signal. However, DAC1
At 0, it is assumed that the input device has the same number of input bits as the number of bits of the digital signal output from the A device 40. ADC2
0 is connected to the input bus 50a of the B device 50, converts the analog signal converted by the DAC 10 into an n-bit digital signal again, and converts this into an input bus 50a,
That is, it is transmitted to the B device 50. The analog signal transmission path 30 has a bus width of one line.
This is for transmitting the analog signal converted by the DAC 10 to the ADC 20.

In the bus transmission control device configured as described above, when the A device 40 outputs an n-bit digital signal, the DAC 10 converts the digital signal into an analog signal, and the analog signal is transmitted from the analog signal transmission line 30 to the ADC 20. Transmit. When receiving the analog signal from the analog signal transmission line 30, the ADC 20 converts the analog signal into n again.
The digital signal is converted into a bit digital signal and transmitted to the B device 50. At this time, the digital signal input to the B device 50 is sampled in synchronization with CLK. Where C
It is assumed that the setup and hold times for the LK are guaranteed by the A device 40 and the transmission delay.

As described above, according to the bus transmission control device of the present embodiment, the DAC 10 is provided on the A device 40 side and the ADC 20 is provided on the B device 50 side.
0 and the ADC 20 can be connected only by the analog signal transmission line 30 for one line. Therefore, n
An n-bit digital signal can be transmitted between the A device 40 and the B device 50 without requiring a bus width for a line.

If both the A device 40 and the B device 50 are on the same substrate, the DAC 10 is arranged near the A device 40 and the ADC 20 is arranged near the B device.
The output bus 40a and the input bus 50a can be shortened, respectively, and wiring of the bus becomes easy. On the other hand, A device 4
When the 0 and B devices 50 are connected by a cable or the like, it is possible to transmit an n-bit digital signal using only two of the analog signal transmission path 30 and the CLK line, and (n
-2) The cost of the cable can be reduced.

In this embodiment, the DAC 10, A
Although the case where one DC 20 and one analog signal transmission line 30 are provided has been described, for example, a plurality of each may be provided as in the invention according to claim 2. That is, as shown in FIG.
.. And a plurality of ADCs 20a, 20b,.
And a plurality of analog signal transmission paths 30a, 30b... May constitute a bus transmission control device.

Normally, when the precision of the DAC is low or when the number of quantization bits of the ADC is small, only one DAC 1
In the 0, ADC 20, and analog signal transmission path 30, a bus width of a sufficient number of bits may not be obtained. However, by providing a plurality of (m) of these and operating them simultaneously, it becomes possible to transmit an n-bit digital signal even using a DAC or ADC with n / m-bit accuracy. In addition, DAC and A with n-bit precision
If DC is used, the frequency of CLK can be reduced to 1 / m.

That is, the plurality of DACs 10a, 10b,.
, A plurality of ADCs 20a, 20b... And a plurality of analog signal transmission paths 30a, 30b.
Since it is possible to use a DC, a DAC and an ADC having a frequency of 1 / m, a wider range of choices can be made, and a more flexible and inexpensive system can be constructed.

[Second Embodiment] Next, a bus transmission control device according to the third aspect of the present invention will be described. The bus transmission control device according to the present embodiment, as shown in FIG.
It is provided between the A device 41 and the B device 51. However, the A device 41 and the B device 51 are different from the first embodiment, and both input and output an n-bit digital signal. Therefore, the A device 41 and the B device 51 have both output buses 41a and 51a and input buses 41b and 51b each having a bus width of n lines.

The bus transmission control device provided between the A device 41 and the B device 51 includes a first DAC 11a
, A second DAC 11b, a first ADC 21a, a second ADC 21b, a first signal transmission path 31a, and a second
And a signal transmission path 31b.

The first DAC 11a is connected to the output bus 41a of the A device 41, and converts a digital signal from the output bus 41a into an analog signal. The second DAC 11b is connected to the output bus 51a of the B device 51, and converts a digital signal from the output bus 51a into an analog signal.

The first ADC 21a is connected to an input bus 51b of the B device 51, converts an analog signal converted by the first DAC 11a into a digital signal, and converts the analog signal into a digital signal.
Is sent to The second ADC 21b is connected to the input bus 41b of the A device 41, and is connected to the second DAC 11b.
Converts the converted analog signal into a digital signal and sends it to the input bus 41b.

The first signal transmission line 31a is connected to the first DAC
11a and the first ADC 21a, and the first DAC
11A is for transmitting the converted analog signal to the first ADC 21a. Second signal transmission path 31b
Connects the second DAC 11b and the second ADC 21b, and outputs the analog signal converted by the second DAC 11b to the second ADC 11b.
Is transmitted to the ADC 21b.

In the bus transmission control device configured as described above, when the A device 41 outputs an n-bit digital signal, the first DAC 11a converts this into an analog signal, and converts the analog signal to the first signal transmission signal. Road 31a is first
To the ADC 21a. When the first ADC 21a receives an analog signal from the first signal transmission path 31a,
Again, the analog signal is converted into an n-bit digital signal and transmitted to the B device 51. On the other hand, when the B device 51 outputs an n-bit digital signal, the second DAC 11b
Converts this into an analog signal, and the analog signal is transmitted by the second signal transmission path 31b to the second ADC 21b. When receiving the analog signal from the second signal transmission path 31b, the second ADC 21b converts the analog signal into an n-bit digital signal again and sends it to the A device 41.

As described above, according to the bus transmission control device of the present embodiment, bidirectional transmission of analog signals between the A device 41 and the B device 51 becomes possible, and the A device 41 and the B device 51 Can exchange data with each other. Further, the first signal transmission path 31a and the second signal transmission path 31
b, that is, separate signal transmission paths are provided, so that simultaneous two-way transmission is possible. Further, in this bus transmission control device, two analog signal transmission paths (first signal transmission path 31a and second signal transmission path 31b) and CLK
The line enables bidirectional transmission between the A device 41 and the B device 51. For this purpose, the first
As in the case of the embodiment, the wiring of the pattern can be facilitated and the cable cost can be reduced.

In this embodiment, a case is described in which the first signal transmission path 31a and the second signal transmission path 31b enable bidirectional transmission between the A device 41 and the B device 51. As described above, the first and second DACs 11a,
11b and the first and second ADCs 21a and 21b can be controlled by high impedance, respectively, for example, as described in claim 4, wherein these are connected by an analog signal transmission line 31c for one line. It may be.

In this case, as shown in FIG. 4, an enable (operation control) signal (hereinafter referred to as OE) from an external device and a signal obtained by inverting the enable signal by an inverter 61 are
First and second DACs 11a and 11b, first and second ADs
C21a and 21b. And this O
E, the first DAC 11a and the first ADC 21a
Only operate, or the second DAC 11b and the second
Is controlled so that only the ADC 21b operates.

In other words, each DAC 11a,
11b and each of the ADCs 21a and 21b. In this way, bidirectional transmission can be performed even with the analog signal transmission line 31c for one line. Therefore, since it is not necessary to provide two analog signal transmission paths, the wiring on the substrate can be simplified.

[Third Embodiment] Next, a bus transmission control device according to the fifth aspect of the present invention will be described. As shown in FIG. 5, the bus transmission control device of this embodiment
It is provided between the A device 42, the B device 43, the C device 44, and the D device 52.

However, A device 42, B device 43, and C device
The device 44 outputs n-bit, 2n-bit, and 4n-bit digital signals, respectively. Therefore, the A device 42, the B device 43, and the C device 44 respectively include an output bus 42a having a bus width of n lines, an output bus 43a having a bus width of 2n lines, and an output bus having a bus width of 4n lines. 44a. On the other hand, the D device 52
A digital signal of a maximum of 4n bits is input. Therefore, the D device 52 has an input bus 52a having a bus width of 4n lines.

The bus transmission control device provided between the A device 42, the B device 43, the C device 44, and the D device 52 includes the DACs 12a, 12b, 12c, the ADC 22,
It comprises an analog signal transmission line 32 and a bus control unit 33.

The DACs 12a, 12b, and 12c are connected to the output bus 4 of the A device 42, the B device 43, and the C device 44, respectively.
2a, 43a, and 44a, and these output buses 4
It converts the digital signals from 2a, 43a and 44a into analog signals. However, the DACs 12a and 12a
b and 12c have different resolutions from n bits, 2n bits and 4n bits, respectively. Also, the DAC 12a,
The outputs of 12b and 12c are each capable of high impedance control.

The ADC 22 is connected to the input bus 52 of the D device 52.
b, and converts the analog signals converted by the DACs 12a, 12b, and 12c into digital signals, and
b. In the ADC 22, DA
Of the C12a, 12b, and 12c, quantization of 4n bits, which is the maximum resolution, is possible.
Inputs at the same level as the outputs of a, 12b, and 12c can be quantized.

The analog signal transmission line 32 is connected to the DAC 12
a, 12b, and 12c, and the ADC 22,
The analog signals converted by 2a, 12b and 12c are converted into ADC signals.
22 for transmission. The bus control unit 33
It outputs enable signals (hereinafter, referred to as AE, BE, CE) to the DACs 12a, 12b, 12c, and supplies these signals to the DACs 12a, 12b, 12c and the D device 52. In the bus control unit 33, these A
DACs 12a, 12b, 12 by E, BE, CE
The high impedance control is performed so that only one of c operates. The A device 42 and the B device 4
3, the C device 44, the D device 52, and the bus control unit 33
Each of them operates in synchronization with CLK from an external device.

In the bus transmission control device thus configured, when the A device 42 outputs an n-bit digital signal, the DAC 12a converts this into an analog signal, and the B device 4
3 outputs a 2n-bit digital signal.
b converts this to an analog signal, and when the C device 44 outputs a 4n-bit digital signal, the DAC 12c converts this to an analog signal. At this time, the DAC 12
In a, 12b, and 12c, conversion into analog signals is performed, but the analog signals are transmitted to the analog signal transmission line 32 only when each enable signal (AE, BE, CE) from the bus control unit 33 is enabled. If the signal is not enabled, the signal is kept at high impedance (an analog signal is not sent to the analog signal transmission line 32).

The ADC 22 includes DACs 12a, 12b, 1
When an analog signal is received from any one of 2c via the analog signal transmission path 32, the analog signal is quantized with a resolution of 4n bits and transmitted to the D device 52. The D device 52 receives each enable signal (A
E, BE, CE), and depending on which is enabled, the input digital signal is output to the A device 42 and the B device 4
3. It is determined from which of the C devices 44 the data is output. Then, the number of valid bits of the input digital signal is determined from the result, and the digital signal having the number of valid bits is received as an input signal.

As described above, according to the bus transmission control device of the present embodiment, even if the A device 42, the B device 43, and the C device 44 output digital signals of different bits, On the other hand, data transmission can be performed by only one analog signal transmission path 32. Thus, in addition to obtaining the same effects as those of the first and second embodiments, simplification of pattern creation and the like can be realized.

In this embodiment, the DAC 12a,
Although the description has been given of the case where each of the 12b and 12c has a different resolution, for example, the DACs 12a and 12b,
As described above, even when 12c has a resolution of 4n bits and the surplus bits are fixed to a low level or a high level,
Data can be transmitted between the devices.

[Fourth Embodiment] Next, a bus transmission control device according to a sixth aspect of the present invention will be described. The bus transmission control device of the present embodiment, as shown in FIG.
It is provided between the A device 45 and the B device 53 and the C device 54. However, the A device 45 outputs an n-bit digital signal.
An output bus 45a having a bus width corresponding to the number of lines is provided. The B device 53 and the C device 54 each receive an n-bit digital signal. Therefore, the input buses 53a and 54a each have a bus width of n lines.
have. The A device 45, the B device 53, and the C device
Each of the devices 54 operates in synchronization with CLK from an external device.

The bus transmission control device provided between the A device 45, the B device 53, and the C device 54 is a DA transmission control device.
It comprises a C13, ADCs 23a and 23b, an analog signal transmission line 34, and look-up tables (hereinafter abbreviated as LUTs) 35a, 35b and 35c.

The DAC 13 converts an n-bit digital signal into an analog signal.
3b converts analog signals into n-bit digital signals. The analog signal transmission path 34 converts the analog signal converted by the DAC 13 into the ADC 2.
3a or to the ADC 23b.

The LUTs 35a, 35b and 35c are composed of, for example, a dual port RAM (Random Access Memory), and are provided between the output bus 45a of the A device 45 and the DAC 13, between the input bus 53a of the B device 53 and the ADC 23a. It is provided between the input bus 54a of the C device 54 and the ADC 23b. These LUTs
34a, 34b and 34c have programmable RAM tables with n-bit inputs as addresses,
When an n-bit digital signal is received, a new digital signal is transmitted based on the value set in the table. However, in the LUTs 35a, 35b, and 35c, control signals (hereinafter, CT signals) from the A device 45 are respectively provided.
LA), a control signal from the B device 53 (hereinafter C)
TL-B), a control signal from the C device 54 (hereinafter, referred to as TL-B).
CTL-C) rewrites the settings in the RAM table.

In the bus transmission control device configured as described above, when the A device 45 outputs an n-bit digital signal, the LUT 35a receives it. At this time, in the A device 45, the CTL-B from the B device 53 and the C device 54,
It arbitrates the CTL-C, and then sends out the CTL-A generated based on the arbitration result to the LUT 35a. This CTL
By -A, the setting of the RAM table is rewritten in the LUT 35a. In addition, the A device 45 notifies the result of the arbitration to the B device 53 or the C device 54 as an enable signal (BE, CE).

When the DAC 13 receives the digital signal transmitted from the LUT 35a, the DAC 13 converts the digital signal into an analog signal, and sends the digital signal to the ADC 23a or the ADC 23b via the analog signal transmission line 34 according to the result of the arbitration in the A device 45. Send out. ADC23a or ADC
At 23b, the received analog signal is converted into a digital signal again and transmitted to the LUT 35b or LUT 35c. At this time, in the LUTs 35b and 35c, the table settings are rewritten by CTL-B and CTL-C, respectively.

Therefore, the LUT 35b and the LUT 35c
Is the same as the table of the LUT 35a rewritten by the CTL-A based on the result of the arbitration in the A device 45. Thereby, the B device 53, C
In the device 54, an L with the same setting as the table of the LUT 35a
Only the one connected to the UTs 35b and 35c can normally receive digital signals. In other words, in this bus transmission control device, A out of B device 53 and C device 54
As a result of the arbitration in the device 45, only the one permitted to use the analog signal transmission line 34 normally receives the digital signal output from the A device 45.

As described above, according to the bus transmission control device of the present embodiment, LUTs are individually provided on both the output side and the input side.
Since the devices 35a, 35b, and 35c are provided, only the device in the RAM table having the same setting as the device on the output side (device A 45) out of the devices on the input side (device B 53 and device C 54) has a normal digital signal. Will be accepted.
Therefore, this bus transmission control device is effective when each device is connected by a cable or the like and it is desired to avoid mutual data leakage. In addition, the analog signal transmission path 3
4 is long or the analog signal transmission line 34 is susceptible to noise, such as when the transmission conditions are poor, the number of effective bits is reduced, and only the digital signal that can ensure the level difference is transmitted to the analog signal transmission line 34. As if
By setting the RAM table of each of the LUTs 35a, 35b, 35c, highly reliable transmission can be realized.

In the above-described first to third embodiments, the DAC and the ADC are the A device, the B device,
Although the case where it is provided separately from the C device and the D device has been described, the present invention is not limited to this. For example, if the A device, the B device, the C device, and the D device are composed of LSIs, the DAC as in the invention according to claim 7
And the ADC may be integrated in each device. In this case, by integrating the DAC and ADC in each device, the number of input / output pins of each device can be reduced, and a small LSI package can be used. As a result, it is possible to reduce the cost of the LSI package and the space for mounting components.

Further, in the above-described fourth embodiment,
DAC, ADC, and LUT are A device, B device, respectively.
Although the case where the device is provided separately from the device and the C device has been described, for example, if the A device, the B device, and the C device are formed of an LSI, the DA device may be configured as described in claim 8.
The C, ADC, and LUT may be integrated in each device. Also in this case, the number of input / output pins of each device can be reduced, and a small LSI package can be used.
It is possible to reduce package cost and component mounting space.

In the above-described first to fourth embodiments, the description has been made mainly of the connection between the devices, but the present invention is also effective for the connection between LSIs in a printed circuit board, for example. Further, in the first to fourth embodiments, the description has been made mainly on the data bus, but the present invention is also applied to, for example, an address bus and a control bus (when a plurality of control lines are treated as a bus). In this case, the same effect as described above can be obtained.

[0049]

As described above, the bus transmission control device in the electronic control circuit according to the present invention has a D / A converter and an A / D converter between an output device and an input device. Therefore, the connection between the D / A converter and the A / D converter can be made only by the analog signal transmission line for one line. Therefore, an n-bit digital signal can be transmitted between the output device and the input device without requiring a bus width of n lines as in the related art. As a result, the number of bus drivers increases, the number of pins of each device such as an IC and an LSI needs to be increased, or the amount of hardware constituting a circuit increases and the number of wiring patterns on a substrate increases. It will not be invited.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a first embodiment of a bus transmission control device according to the present invention.

FIG. 2 is a schematic configuration diagram of a modification of the first embodiment according to the present invention.

FIG. 3 is a schematic configuration diagram of a second embodiment of the bus transmission control device according to the present invention.

FIG. 4 is a schematic configuration diagram of a modification of the second embodiment according to the present invention.

FIG. 5 is a schematic configuration diagram of a third embodiment of the bus transmission control device according to the present invention.

FIG. 6 is a schematic configuration diagram of a fourth embodiment of a bus transmission control device according to the present invention.

FIG. 7 is an explanatory diagram showing bus transmission in a conventional electronic control circuit.

[Explanation of symbols]

10, 10a, 10b, 12a, 12b, 12c, 13
DAC 11a first DAC 11b second
DAC 20, 20a, 20b, 22, 23a, 23b ADC 21a first ADC 21b second
ADC 30, 30a, 30b, 31c, 32 Analog signal transmission path 31a First signal transmission path 31b Second
Signal transmission path 33 bus control units 40, 41,
42, 45 A device 43, 50, 51, 53 B device 44, 54
C device 52 D device

Claims (8)

[Claims] A bus transmission in an electronic control circuit provided between an output device that outputs a digital signal and an input device to which the digital signal is input, and that transmits the digital signal output by the output device to the input device. In the control device, a D / A converter that receives the digital signal output from the output device and converts the digital signal into an analog signal; and converts the analog signal converted by the D / A converter into a digital signal again to input the digital signal. An A / D converter to be sent to a device; and an analog signal converted by the D / A converter.
A bus transmission control device in an electronic control circuit, comprising: an analog signal transmission path for transmitting the signal to a converter. 2. The D / A converter, the A / D converter,
2. A bus transmission control device in an electronic control circuit according to claim 1, wherein a plurality of said analog signal transmission paths are provided. 3. A bus transmission control device in an electronic control circuit provided between a plurality of input / output devices for inputting / outputting digital signals and transmitting a digital signal output from one input / output device to another input / output device. , Provided corresponding to each of the plurality of input / output devices,
A plurality of D / A converters for receiving digital signals output from the plurality of input / output devices and converting the digital signals into analog signals; and provided corresponding to each of the plurality of input / output devices,
A plurality of A / D converters for converting the analog signals converted by the plurality of D / A converters into digital signals again and sending them to each input / output device; the plurality of D / A converters and the plurality of A / D converters A bus transmission control device in an electronic control circuit, comprising: a plurality of analog signal transmission paths for transmitting analog signals simultaneously and bidirectionally with a / D converter. 4. A bus transmission control device in an electronic control circuit provided between a plurality of input / output devices for inputting / outputting digital signals and transmitting a digital signal output from one input / output device to another input / output device. , Provided corresponding to each of the plurality of input / output devices,
A plurality of D / A converters for receiving digital signals output from the plurality of input / output devices and converting the digital signals into analog signals; and provided corresponding to each of the plurality of input / output devices,
A plurality of A / D converters for converting the analog signals converted by the plurality of D / A converters into digital signals again and sending them to each input / output device; the plurality of D / A converters and the plurality of A / D converters One analog signal transmission line for transmitting an analog signal to / from a plurality of D / A converters; and one of the plurality of D / A converters and the plurality of A / D converters The plurality of D / A converters such that only the converter and any one of the A / D converters operate.
A bus transmission control device in an electronic control circuit, comprising: a converter and operation control means for controlling the plurality of A / D converters. 5. An electronic device for transmitting a digital signal output from each output device to the input device between a plurality of output devices outputting digital signals having different numbers of bits and an input device receiving the digital signal. A bus transmission control device in a control circuit, wherein a plurality of D / A converters are provided corresponding to each of the plurality of output devices and receive digital signals output by the plurality of output devices and convert the digital signals into analog signals. An A / D converter for converting each analog signal converted by the plurality of D / A converters into a digital signal again and sending the digital signal to the input device; and an analog converted by the plurality of D / A converters. An analog signal transmission path for transmitting a signal to the A / D converter; and an analog signal transmitted by the analog signal transmission path, wherein the analog signal is transmitted from the plurality of D / A converters. Bus transmission controller in the electronic control circuit, characterized in that it comprises a bus control means for notifying whether those converted by the D / A converter to the input device. 6. A bus transmission in an electronic control circuit which is provided between an output device for outputting a digital signal and an input device to which the digital signal is input, and transmits the digital signal output from the output device to the input device. In the control device, a first table conversion unit that replaces the digital signal output from the output device with a new digital signal according to a preset setting, and converts the new digital signal replaced by the first table conversion unit into an analog signal A D / A converter that transmits the analog signal converted by the D / A converter; and an A / A converter that receives the analog signal transmitted by the analog signal transmission line and converts the analog signal into a digital signal. A D converter and a digital signal converted by the A / D converter by the first table conversion means in accordance with a preset setting. A second table conversion unit for replacing the digital signal with a digital signal before replacement, wherein the second table conversion unit is configured such that a preset setting in the second table conversion unit is a preset setting in the first table conversion unit. And transmitting the replaced digital signal to said input device if the same. 7. The D / A converter is built in the output device or the input / output device, and the A / D converter is built in the input device or the input / output device. A bus transmission control device in an electronic control circuit according to claim 1, 2, 3, 4, or 5. 8. The D / A converter and the first table converter are built in the output device, and the A / D converter
7. The bus transmission control device in an electronic control circuit according to claim 6, wherein a D converter and the second conversion means are built in the input device.