SPI-based token ring networking method

Abstract

The invention discloses an SPI-based token ring networking method. An SPI is used as a token ring network communication protocol, the network contains one master device and multiple slave devices, alldevices form a ring shape through an SPI output and input line, SPI clock signals of all slave devices are provided by the master device, SPI chip selection signals of all slave devices are providedby the master device, the same SPI chip selection signal is adopted, the master device initiates a round of transfer of a token, and the slave devices judge whether to process information according totoken ring contents. According to the token ring networking method disclosed by the invention, token ring networking can be performed on the multiple slave devices and the master device just by usingone chip selection signal so as to perform token exchange, the slave devices can communicate with each other, the pin burden of the master device in the SPI communication is reduced, and the SPI-based token ring networking method is especially suitable for the networking of single chip microcomputers with insufficient on-chip pin resources.

Description

technical field [0001] The invention belongs to the technical field of embedded system communication, and in particular relates to an SPI-based token ring networking method. Background technique [0002] SPI (Serial Peripheral Interface) is a serial peripheral interface, which is a full-duplex, high-speed communication protocol. Most embedded chips have SPI functions, which only occupy four wires, saving the pins of the chip. A very efficient and universal means of communication. [0003] The token ring network refers to physically connecting the communication nodes into a ring structure, and sequentially transmitting a data packet called a token on the ring node set, and each node judges whether it needs to receive or modify the token data, and if necessary If it is received or modified, otherwise, the token will continue to be transmitted to the subsequent node, so that the token moves in a directional ring on the ring node set. [0004] Traditionally, in the case of mul...

AI Technical Summary

Problems solved by technology

This communication method has obvious disadvantages: first, if communication between slave devices is required, it needs to go through the master device, which increases the burden on the master device; second, multiple pins are required to control chip select signals of different slave devices, This makes the pin usage of the master device limited

Images