Circuit for expanding 18 bits of 51 single-chip microcomputer into 128-bit interface

Abstract

The invention discloses a circuit for expanding 18 bits of a 51 single-chip microcomputer into a 128-bit interface. A simple parallel interface expansion mode is used, and eight groups of same circuits are respectively connected with a 51 single-chip microcomputer. Each group of circuits comprises a 74LS273 chip, a 74LS244 chip and two 74LS32 chips. A reset end MR of the 74LS273 chip is connectedwith a power supply, a clock end CLK is connected with an output end of a 74LS32 chip, one pin of the input end of the 74LS32 chip is connected with a WR pin P3.6 of the single-chip microcomputer, andpins D0-D7 are connected with pins P0.1-P0.7 of the 51 single-chip microcomputer. Two gating end OE pins of the 74LS244 chip are connected with the output end of the other 74LS32 chip. One pin of theinput end of the 74LS32 chip is connected with an RD pin P3.7 of a single chip microcomputer, eight pins of the Y end of the 74LS32 chip are sequentially connected with P0.1 to P0.7 of a 51 single chip microcomputer, 18 pins of the 51 single chip microcomputer are expanded, 64 input pins and 64 output pins are obtained, and 128 pins are provided in total. 32 input and output pins of the 51 single-chip microcomputer are expanded into 64 input pins, 64 output pins and 14 input and output pins, and the total number of the pins is 142, so that the defect that the number of the pins of the 51 single-chip microcomputer is small is overcome.

Description

technical field [0001] The present invention relates to the technical field of embedded control technology, and specifically relates to a circuit in which 18 bits of 51 single-chip microcomputers are expanded into 128 bits of interfaces. Background technique [0002] Nowadays, there have been some research results in the development of peripheral circuits of single-chip microcomputers. Patent announcement number CN204537576U, a single-chip microcomputer expansion training module equipment, mainly expands the training of analog-to-digital conversion, stepping motor, and ultrasonic distance measurement. Patent announcement number CN106168777A, a single-chip microcomputer extended function coding trigger device, including a sequential circuit, a first photocoupler, a first signal generation circuit and a second signal generation circuit, providing two signals for the single-chip microcomputer within the same time period. Overlapping and intersecting trigger signals occur. Pat...

AI Technical Summary

Problems solved by technology

The above-mentioned research results have carried out various expansions on the single-chip microcomputer, but without using the I / O expansion special chip 8255, 8155, etc., no one has expanded the I / O port pins of the 51 single-chip microcomputer.

[0003] 51 single-chip microcomputer is a chip often encountered in embedded control. Compared with the high-end 32-bit single-chip microcomputer STM32F4, etc., it does not use library functions and is easy to use, but there are too few input and output pins, only 32 pins. In the actual use process There are often insufficient I / O ports

Images