JPH0314018A - Input/output circuit - Google Patents

Abstract

PURPOSE:To reduce the number of input/output signal lines and the number of input/output ports on the control side by providing a shift register circuit, and transferring output data to plural display elements and input data to plural input elements by one bidirectional data transfer line. CONSTITUTION:Plural light emitting diodes 5 as display elements and plural switches 6 as input elements are provided, and each light emitting diode 5 is connected to a shift register circuit 2 for output to display elements through a corresponding driver circuit 4, and each switch 6 is connected to a shift register circuit 3 for input to input elements. Data is transferred to the shift register circuit 2 for output to display elements in serial by one output signal line 8 and one strobe line 10 corresponding to this line, and input data of plural input elements from the shift register circuit 3 for input to input elements is transferred in serial by one input signal line 9. Thus, the number of input/output signal lines to display elements 5 and input elements 6 is reduced to reduce the number of input/output ports.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an input/output circuit for an operation panel or the like having a plurality of light emitting diodes as display elements and switches as a plurality of input elements.

[Conventional technology]

Conventionally, each element has been controlled independently as an input/output circuit for an operation panel or the like having a plurality of display elements and a plurality of input elements. That is, each of the plurality of display elements had an output circuit and an output signal, and each of the plurality of input elements had an input circuit and an input signal.

[Problem to be solved by the invention]

For this reason, it was necessary to prepare as many input/output signal lines as there were input/output elements, and to prepare as many input/output ports on the control side as there were input/output elements.

[Means to solve the problem]

The present invention provides a shift register circuit as an output circuit for a display element and a shift register circuit as an input circuit for an input element, thereby reducing the input/output signals to the display element and input element. This aims to reduce the number of input/output ports.

[Effect]

Data transfer to the shift register circuit for display element output is 1
It is serially outputted by two output signal lines and one strop line for each output signal line.

Input data from the input element input shift register circuit is serially transferred from a plurality of input elements through one input signal line. ``Serial transfer timing is switched by a strobe line.The output signal line and the input signal line are coupled to each other and function as one bidirectional data transfer line.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

Referring to FIG. 1, an embodiment of the present invention includes a light emitting diode 5 as a display element and a switch 6 as an input element. The seven light emitting diodes 5 are connected to the display output shift register circuit 2 through the corresponding driver circuits 4, while the seven switches 6 are connected to the input element input shift register circuit 3.

The output signal line 8 to the display element output shift register circuit 2 and the input signal line 9 from the input element input shift register circuit 3 are connected to each other and connected to the microprocessor IIC as bidirectional data transfer 2/7. . Stroke line 10 for output to the display element output shift register circuit 2 and input element input shift register circuit 3
A strobe light/11 for input from the microprocessor 1 is connected between each shift register circuit and the microprocessor 1.

Next, the output to the light emitting diode will be described.

The on-off data of the seven light emitting diodes is serially transferred through the bidirectional data transfer line 7. First, on/off data of the light emitting diode (1) is set in the display element output shift register 2 by the action of the strobe line 10. Next, the on/off data of the light emitting diode (2) is similarly set in the display element output shift register 2. At this time, the data of the light emitting diode (2) is shifted. Thereafter, seven pieces of data are transferred in the same way, and output to the seven light emitting diodes is completed. Next, let's talk about switch input. The seven switch information is inputted to the input element input shift register circuit 3 in parallel, but is serially outputted sequentially from the strobe line IIK. This serial output is read by microprocessor 1 through input signal line /9 and bidirectional data transfer line 7.

〔Effect of the invention〕

The present invention provides a shift register circuit as described above, and enables outputs to multiple display elements and inputs to multiple input elements to be transferred through a single bidirectional data transfer line. It has the effect of

Circuit, 5... Light emitting diode, 6...
・Switch, 7... Bidirectional data transfer line,
8... Output signal line, 9... Input signal line, 10.11... Stroke line.

Claims (1)

[Claims] In an input/output circuit having a plurality of display elements and a plurality of input elements, a shift register circuit for outputting the display elements, a shift register circuit for inputting the input elements, and one line for the shift register circuit for outputting the display elements. an output signal line, one stroke line, and one input signal line to the input element input shift register circuit;
1. An input/output circuit having one stropline, and an output signal line and an input signal line being coupled to each other.