JPH01177623A - Microcomputer system - Google Patents

Abstract

PURPOSE:To dispense with the oscillating circuit and oscillator of a front panel controller (FPC) by supplying the system clock of the FPC from a microcomputer. CONSTITUTION:When a microcomputer 100 is operated by the system clock generated by an oscillator and oscillating circuit 102, the clock is supplied through a frequency-divider 103 also to an FPC 104. When the FPC 104 is a 1-chip microcomputer, etc., an action is executed in making the clock supplied from a microcomputer 1 into the system clock, and a display 105 and a key input part 106 are operated. By enlarging the frequency-dividing ratio of the frequency-divider 103, a low-speed FPC can be corresponded to. Thus, the oscillating circuit and oscillator of the FPC can be made unnecessary.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is applicable to microcomputers and especially FPCs (Front PCs).
nt Panel Controller).

[Conventional technology]

Conventionally, the oscillation circuit of this type of system includes an oscillation circuit 102 for operating a microcomputer 100 and an oscillation circuit 107 for operating an FPC 104, as shown in FIG.
Each had an oscillator and was operated by an independent system clock.

[Problem that the invention seeks to solve]

The above-described conventional oscillation circuit has the disadvantage that it is expensive because the microcomputer and FPC each require an oscillator for the oscillation circuit.

[Means for solving problems]

The system clock of the system microcomputer according to the present invention is characterized by operating peripheral digital circuits either as is or by dividing the frequency.

〔Example〕

Hereinafter, the present invention will be explained using the drawings.

FIG. 1 is a block diagram of a first embodiment of the invention. 100 is a microcomputer, 102 is an oscillation circuit and an oscillator that generates the system clock for the microcomputer 1, 103 is a divider that divides the clock generated by 2 by N, and 104 is a display 105 and a key input. FPC (Front
PanelContrpHer).

Now, when the microcomputer 100 is operating with the system clock generated by the oscillator and oscillation circuit 102, the FPC
104 is also supplied with a clock. If FPC104 is a 1-chip microcomputer, etc., it is a microcomputer.
It becomes possible to operate the clock supplied from the computer 1 as the system clock, and the display 105
and operates the key human power section 106. Also, frequency divider 1
By increasing the frequency division ratio of 03, it becomes possible to support low-speed FPC.

FIG. 2 is a block diagram of a second embodiment of the invention. If the frequency division ratio of the frequency divider 103 is made programmable, for example, the FPC 104 can be
By changing the frequency division ratio when the FPC 104 is used as a display driver for the FPC 104, the system clock of the FPC 104 changes, and the brightness of the fluorescent display tube can be varied.

FIG. 4 is a block diagram of a third embodiment of the invention. The difference from FIG. 1 is that a switch 107 is provided in series with the clock supply line to the FPC 104.

Now, when the switch 107 is on and the microcomputer 100 is operating with the system clock generated by the oscillator and the oscillation circuit 102,
A clock is also supplied to the FPC 104. If the FPC is a 1-chip microcomputer, etc., it is a microcomputer.
The clock supplied from the computer 1 can be used as a system clock to operate the display 5 and the key power section 6. By increasing the frequency division ratio of the frequency divider 103, it becomes possible to support low-speed FPC. When the microcomputer 100 enters the backup mode, current consumption increases if the clock is continued to be supplied to the FPC 104. Therefore, if the switch 107 is turned off by the program, the current consumption of the FPC decreases, and only the microcomputer 100 backup mode.

FIG. 6 is a block diagram of a fourth embodiment of the present invention. Here, if 0N10FF of the switch 107 is programmable, for example, when the FPC'104 is used as a display driver of a fluorescent display tube, by turning off this switch 107, the FPC'104
When the system clock reaches 0FFL, it becomes possible to turn off the display on the fluorescent display tube. Furthermore, if the frequency division ratio of the frequency divider 103 is also programmable, the clock supplied to the FPC can be varied, so that the brightness of the display can also be changed.

〔Effect of the invention〕

As explained above, the present invention is effective in that by supplying the FPC system components with a microcomputer, the oscillation circuit and oscillator of the FPC are unnecessary, and the cost is reduced.

Furthermore, since the microcomputer and FPC can be synchronized, data communication etc. can be simplified.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a first embodiment of the present invention, FIG. 2 is a block diagram of a second embodiment of the present invention, FIG. 3 is a conventional block diagram, and FIGS. 4 and 5. are block diagrams showing third and fourth embodiments of the present invention, respectively. 100...Micro computer, 102.
...Resonator and oscillation circuit, 103...
Frequency divider, 104... FPC (front panel controller), 105... Display unit, 106
...Key Human Power Department, 107...Switch. Agent Patent Attorney Uchihara Oto-1 d = 134-

Claims (1)

[Scope of Claims] A microcomputer including an oscillation circuit and a peripheral digital circuit operated by a clock, and a clock obtained by the oscillation circuit of the microcomputer is supplied to the peripheral digital circuit to control the peripheral digital circuit. A microcomputer system that operates circuits. 2. The microcomputer system according to claim 1, wherein the clock is obtained by dividing the output of the oscillation circuit of the microcomputer using a programmable frequency divider.