JPS6238921A - Terminal equipment - Google Patents

Abstract

PURPOSE:To decrease the number of parts and to reduce package area and manufacture mandays by controlling a keyboard and a display device by one one-chip CPU in common. CONSTITUTION:A key code is outputted to a keyboard control circuit 9 and when the key code coincides with a pressed key switch, the output of a data selector 4 turns on; and a program senses the level sense terminal T1 of the one-chip CPU 2 and when its on state is confirmed, the key code is read in a master CPU 1, so an interruption to the master CPU 1 is initiated in the output buffer of the one-chip CPU 2. The interruption is caused by the timer in the one-chip CPU 2 at certain constant intervals of time and a fluorescent display tube is controlled. If the interruption is caused when data is written in the one-chip CPU 2 from the master CPU 1, the analysis of a command or storage of display data is carried out and input data processing is finished at the end of this interruption.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a terminal device equipped with a keyboard and a display device, and particularly to a control circuit thereof.

[Bottle already required]

The present invention provides a terminal device equipped with a keyboard and a display device, in which the control of the keyboard and display device is performed using one chip C.
By using PU, the mounting area and manufacturing man-hours are reduced, and the cost of the device is reduced.

[Conventional technology]

Conventionally, in a terminal device equipped with a keyboard matrix and a display device consisting of, for example, a fluorescent display tube, the keyboard control circuit and the fluorescent display tube control circuit were each controlled using their own control circuits consisting of a single-chip CPU. .

[Problem that the invention seeks to solve]

In the conventional terminal device described above, the keyboard control circuit and fluorescent display tube control circuit each have their own one-chip CPU.
Since the control is carried out by the following, the number of parts increases, which increases the mounting area and manufacturing man-hours, which has the drawback of increasing the cost of the device.

An object of the present invention is to provide a terminal device with a small number of parts (therefore, a small mounting area, a small number of manufacturing steps, and a reduction in device cost) by eliminating the above-mentioned drawbacks.

[Means for solving problems]

The present invention provides a terminal device including a keyboard, a display device, and a control circuit for controlling the keyboard device and the display device, wherein the control circuit is a single chip that commonly controls the keyboard and the display device. CPU
It is characterized by including.

[Effect]

The present invention provides a keyboard control circuit and a display device control circuit.
Since it is configured to perform control using a single 1-chip CPU, the number of parts for the control circuit can be reduced compared to conventional methods.

Therefore, the mounting area of the device and the number of manufacturing steps can be reduced, and the manufacturing cost can be reduced.

〔Example〕

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

FIG. 1 is a block diagram showing one embodiment of the present invention. The 1-chip CPU 2 and the master CPU 2 are connected via a bus interface by a signal vA1) to have a minimum configuration, and the 1-chip CPU 2 is accessed by the I10 instruction of the master CPU. The keyboard control circuit 9, the fluorescent display tube control circuit 10, and the two I10s each have a 1-deep CPU.
City 1) '< is distributed by ports P1 and P2. I10
The 3rd to 6th bits of boat P1 are signal line 1.
2 is connected to the decoder 3, and the 0th bit to the 2nd bit of the I10 port P1 are connected to the data selector 4 through a signal line 13. Further, all the bits of the I10 port P1 are connected to the 3rd bit to the 10th bit of the 1) bit of the address of the character generator 6 by the signal line 15. The 0th to 2nd bits of the other I10 baud) P2 are connected to the 0th to 2nd bits of the 1) bits of the address of the character generator 6 through a signal line 17. The third bit of I10 port P2 is connected to the enable terminal of data selector 4 through signal line 16 and to the enable terminal of latch circuit 7 through signal line 18. The 4th bit of the I10 port P2 is used as a key human interrupt line to the master CPU via the signal line 20, and the 5th to 7th bits of the I10 port P2 are used as the control signal line of the latch circuit 7 via the I word line 19. Use as. The output of the data selector 4 is connected to the level sense terminal T1 of the 1-chip CPU 2 through the signal line 14.
Connect to.

A feature of the present invention is that, as shown in FIG. 1, a one-chip CPU 2, a keyboard control circuit 9 and a fluorescent display tube control circuit 10 controlled by the one-chip CPU 2 are provided.

Next, the operation of the present invention will be explained. Figure 2 fa),
C1 is an operation timing chart of the one-chip CPU 2. When it is ON, it indicates that program control is being executed, and when it is OFF, it indicates that program control is being suspended.

The keyboard/display control program according to the present invention has main processing as shown in Fig. 2+1). 1 keyboard control is being executed. Keyboard control means that a key code is output to the keyboard control circuit 9, and when the key code matches the pressed key switch, the output of the data selector 4 is turned on, and the program is executed on one chip CP.
This means that the level sense terminal TI of U2 is sensed, and when it is confirmed that it is on, the output sofa of the 1-chip CPU 2 is written to generate an interrupt to the master CPUI in order to cause the master CPUI to read the key code.

During execution of this process, two types of interrupts occur.

One of them is 1 shown by points A1 and C in Figure 2 fal.
This is an interrupt caused by a timer within the chip CPU 2, and occurs at certain regular intervals. This interrupt processing executes fluorescent display tube control. Fluorescent display tube control means latching the character generator pattern of the next digit to be displayed and outputting it to the fluorescent display tube. Immediately after the character generator pattern is output to the optical display tube. Therefore, keyboard control is interrupted during the period TI of this interrupt processing.

Another interrupt occurs when data is written from the master CPU to the 1-chip CPU2, as shown by the dots bl in Figure 2.This interrupt process executes command analysis or display data storage. Figure 2(b)
The end of this interrupt, indicated by point E, occurs after input data processing is completed. During the period T2 of this interrupt processing, FIG.
Keyboard control is interrupted as in C1.

As described above, according to this embodiment, the keyboard control circuit 9 and the fluorescent display tube control circuit 10 can be controlled without using two I-chip CPUs.

〔Effect of the invention〕

As explained above, the present invention can reduce the number of parts by commonly controlling the keyboard and display device with one single-chip CPU, which reduces the mounting area and manufacturing man-hours, resulting in lower device costs. effective.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention. Fig. 2 (al, (bl, (C1 is its operation timing chart. 1... Master CPU, 2... 1-chip CPU, 3
...Decoder, 4...Decoder selector, 5...
Keyboard matrix, 6... Character generator, 7... Latch circuit, 8... Fluorescent display tube, 9...
- Keyboard control circuit, 10... Fluorescent display tube control circuit, 1) to 20... Signal lines.

Claims (1)

[Claims] (1) In a terminal device that includes a keyboard, a display device, and a control circuit that controls the keyboard device and the display device, the control circuit is a one-chip CPU that commonly controls the keyboard and the display device. A terminal device comprising: