JPS62239258A - Microcomputer - Google Patents

Abstract

PURPOSE:To quickly cope with the request of many users only by the change of the mask of a wiring process by building in a means to make the initial value of an output signal into plural different values and changing over with a wiring which means is to be used. CONSTITUTION:When the internal part of a wiring changing-over part 6 is connected to the resetting side of a data latch 1, the data latch 1 is reset by a resetting signal and the output of an output buffer 3 comes to be a high impedance. When the internal part of the wiring changing-over part 6 comes to be the setting side of the data latch 1, the output buffer 3 outputs the contents of a data latch 2 by a resetting signal. Here, the value outputted from the output buffer 3, when a wiring changing-over part 7 is not wired, comes to be the holding contents of the data latch 1 regardless of the resetting signal, when the internal part of the wiring changing-over part 7 is connected to the resetting side of the data latch 2, it comes to be a low level output by the resetting signal and when the part is connected to a setting side, it comes to be a high level output.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application] The present invention relates to a microcomputer, and more particularly to a microcomputer that can control signals output from an output terminal after reset.

[Conventional technology]

Conventionally, this crosspiece micro combinator has been integrated into an integrated circuit, and the initial value of the signal output from the output terminal after reset is determined by the circuit configuration prepared by the manufacturer.

In order to change the specifications and set the output signal after reset to a different value, it is necessary to change the circuit configuration and use a different type.

[Problem that the invention seeks to solve]

Since a general-purpose integrated circuit microcomputer is used by many users in different application circuits, the output value after reset cannot necessarily satisfy all users, as described above.

There is also the problem that it is difficult for manufacturers to satisfy the demands of individual users.

[Failure to solve the problem]

The microcomputer of the present invention has a means for outputting information inside an integrated circuit to the outside, and a reset means for generating a reset signal for initializing the circuit. Control the input signal. It is characterized by having a first control means and a second control means capable of controlling the output of the means for outputting to the outside to a high impedance in response to a reset signal.

〔Example〕

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

FIG. 1 is a circuit block diagram representing one embodiment of the present invention. Data latches 1 and 2 with set/reset are connected to the internal path via write gates 4 and 5, and an output buffer 3 that becomes high impedance due to the output of data latch 1 is connected to the output of data latch 2. The output of the wiring switching unit 6 is connected to the set input and reset input of the data latch 1, the output of the wiring switching unit 7 is connected to the set input and reset input of the data latch 2, and the output of the output buffer 3 is integrated. This is the output of the circuit, and a reset signal is input to the inputs of the wiring switching units 6 and 7.

If the inside of the wiring switching section 6 is connected to the reset side of the data latch 1, the data latch 1 is reset by the reset signal, and the output of the output buffer 3 becomes high impedance.

When the inside of the wiring switching section 6 is on the set side of the data latch 1, the output buffer 3 outputs the contents of the data latch 2 in response to a reset signal. Here, the value output from the output buffer 3 will be the content held in the data latch 1 regardless of the reset signal if the wiring switching section 7 is not wired, and the inside of the wiring switching section 7 will be on the reset side of the data latch 2. If it is connected, it will be a low level output with the reset signal, and if it is connected to the set side, it will be a high level output.

In this embodiment, by changing the wiring of the wiring switching units 6 and 7, it is possible to select high impedance, holding the value before reset input, low level output, and high level output as the initial output value by the reset signal. .

〔Effect of the invention〕

As explained above, the present invention has a built-in means for setting the initial value of an output signal to a plurality of different values, and has a configuration in which which means to use can be switched by wiring, so that many problems can be achieved simply by changing the mask in the wiring process. This has the effect of providing a microcomputer that can quickly respond to user requests.

[Brief explanation of drawings]

FIG. 1 is a circuit block diagram of an embodiment of the present invention. ■...Data latch, 2...Data latch, 3...Output buffer, 4...Write gate, 5...Write Gate, 5...
Write gate, 6... Wiring switching section, 7...
Wiring switching section. 1---Chi°゛-Kurazuto 7-・Seikenkiri sound β

Claims (1)

[Claims] In a microcomputer that has means for outputting information inside an integrated circuit to the outside and reset means for generating a reset signal for initializing the circuit, there is a method for controlling signals input to the means for outputting to the outside using the reset signal. 1. A microcomputer comprising a first control means and a second control means capable of controlling the output of the means for outputting to the outside to a high impedance based on a reset signal.