A single-chip microcomputer ultra-large data external storage expansion system and its control method

Abstract

The invention discloses a single chip extra-large data external memory extension system and a control method thereof. The system comprises a single chip, a plurality of first decoders, a plurality of extended I / O port chips, a plurality of second decoders and a plurality of memories, wherein each of the memories is connected with address, data and control buses of the single chip; an input end of each of the first decoders is connected with the address bus of the single chip and an output end of each of the first decoders is connected with an enabling end of each of the extended I / O port chips; an input end of each of the extended I / O port chips is connected with the data bus of the single chip; the extended I / O port chips correspond to the second decoders one to one; an input end of each of the second decoders is connected with an output end of the corresponding extended I / O port chip; an output end of each of the second decoders is connected with a chip selection port of each of the memories. According to the single chip extra-large data external memory extension system and the control method thereof, the capacity limit of the traditional extension method is broken through, and the real-time access demand of ultra-large capacity is satisfied.

Description

Technical field [0001] The invention belongs to the technical field of single-chip storage, and particularly relates to a single-chip ultra-large data external storage expansion system and a control method thereof. Background technique [0002] With the increasing popularity of computer network communication, the construction of computer data storage capacity becomes more and more important. However, the number of address pins of the MCU limits the memory access capacity. Therefore, how to expand the memory of the MCU more to meet the large-capacity storage requirements has become a problem that people in this technical field need to solve. [0003] The existing MCU storage expansion methods are roughly divided into two types: [0004] 1. Expand the access capacity through the P1 and P3 pins of the microcontroller, but this method is limited by the number of P1 and P3 ports, and the expanded capacity is very limited. For example, a common MCS51 microcontroller can only expand up to...

AI Technical Summary

Problems solved by technology

[0004] 1. Expand the access capacity through the P1 and P3 pins of the single-chip microcomputer, but this method is limited by the number of P1 and P3 ports, and the expanded capacity is very limited. For example, the ordinary MCS51 single-chip microcomputer can only expand up to 256*256 memory (full decoding); and occupy the I / O port P1, P3 pins;

[0005] 2. Expansion through the serial port, such as using the serial-to-parallel chip 74LS164 to convert the serial port data into parallel port data, and connect the CS (chip select) pin of each memory to achieve expansion, but the disadvantage of this method is that the more expansion, The longer the serial port is sent, the real-time performance is not good, and the serial port of the MCU is occupied, which increases the difficulty and cost

Images