JPS63114321A - Ad converter - Google Patents

Abstract

PURPOSE:To relieve the load to an external device by storing the selective sequence of analog input channels and the conversion cycle so to automatically select the channel and outputting a data subject to AD conversion together with a data representing the channel. CONSTITUTION:A channel selection data from a data input/output line D and a conversion cycle setting data for each channel are stored in a storage section 8 and sent to a timer section 6. A timer section 6 detects an analog conversion timing and the sampling timing of the analog signal is supplied to sample-and- hold circuits 50-5n and a start command of AD conversion is issued to a control section 7. The control section 7 selects the channel by the analog channel switching circuit 17 and the AD converter 2 applies AD conversion. After the data is added with a channel data selected by the control section 7 in the data synthesizing section 3 and outputted to the data input/output line D through the data output buffer 4.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a circuit configuration of an AD converter.

BACKGROUND OF THE INVENTION Conventionally, AD converters having a plurality of analog input channels have been configured so that selection of the analog input channels can be set externally each time.

FIG. 2 shows an example of the configuration of a conventional AD converter.

This figure shows the side of an AD converter with a microcomputer ink face. When channel selection data is set in the channel switching control section 9 through the data input/output line, the channel switching circuit 1 selects the analog input channel A. -A,
, switch. The data of the switched channel is AD
The signal is sent to a converter 2 where AD conversion is performed. The converted data is output to the output buffer 4 and then output from the data input/output line.

Problems to be Solved by the Invention The conventional A/D converter described above can arbitrarily select an analog input channel, but each time the input channel is switched, the A/D conversion result is read out and the next channel selection data is transmitted externally. It is necessary to input more information. Furthermore, when AD conversion is performed at regular intervals, time management must be performed externally, which places a heavy burden on the outside, such as time management for channel switching.

Means for Solving the Problems The AD converter of the present invention has a plurality of analog input channels, and the selection of each channel can be set externally.
A converter, comprising a circuit that stores the selection order and conversion cycle of analog input channels, and means that automatically selects an analog input channel according to the stored contents and performs AD conversion of the data of the selected channel. ,
and means for outputting the data converted by the AD conversion hand together with data indicating the channel.

Example Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a diagram showing an example of the configuration of the present invention. Channel selection data from the data output line and conversion cycle setting data for each channel are stored in the storage unit 8.

The stored data is sent through a control section 7 to a timer section 6 that manages the time of the conversion cycle. The timer part 6 detects analog conversion timing. This timer part 6 is analog input channel A. -Ah provides the sampling timing of the analog signal to the sample and hold circuits 5° to 5° provided respectively, and issues an AD conversion start command to the control unit 7. In response to this start command, the control section 7' selects the analog channel using the channel switching circuit 1. The input of the selected channel is subjected to AD conversion by the AD converter 2. The converted data is sent to the data synthesis section 3 and then to the control section 7.
After adding the selected channel data, the data is outputted to the data output line through the data output buffer 4.

As described in detail, the present invention enables channel switching to be performed automatically and in constant cycles by setting channel selection data and its conversion cycle only once, and to add channel data to conversion data. Since the converted data is outputted, if the outputted data is read out sequentially, it is easy to distinguish which channel the converted data belongs to, and the burden placed on the outside can be significantly reduced. Therefore, the AD according to the present invention
When a converter is connected to a microcontroller, the burden on the microcontroller is reduced, which in turn improves system performance.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of the configuration of an AD converter according to the present invention, and FIG. 2 is a diagram showing an example of the configuration of a conventional AD converter. (Main reference numbers) 80~AI, Analog input channel D, Data output line 1, Channel switching circuit 2, AD converter 3, Data synthesis unit 4, Data output buffer 5゜~5r1...Sample/hold circuit 6...Timer part 7...Control section 8...Storage section 9...Channel switching control section

Claims (1)

[Claims] An AD converter that has multiple analog input channels, and the selection of each channel can be set externally, and includes a circuit that stores the selection order and conversion cycle of the analog input channels, and automatically converts the selection order of the analog input channels and the conversion cycle according to the stored contents. An AD converter comprising means for selecting an analog input channel and performing AD conversion on the data of the selected channel, and means for outputting the data converted by the AD conversion means together with data indicating the channel. .