Interface circuit based on serial bus structure and communication protocol

Abstract

The invention discloses a bus interface circuit based on a serial bus structure and a bus communication protocol thereof; the bus interface circuit uses a logic combination, formed by an emission data line, an emission control line and a competition control line, to realize strong pull up, weak pull up and strong pull down drive output of a bus level; the bus interface circuit combines a bus logic level read back function, and supports the bus communication protocol allowing bus nodes to compete the bus control right in a non-destructive arbitration and automatic back off mode; the nodes monitor the bus state, determine bus idle state, and bus level preset and assignment based on node address bits can ensure the information sent to the bus by the node with the minimum address value not to be destroyed in a bus control right compete process of competing nodes; the bus control right can be re-competed by nodes until all application data is sent, thus realizing node multi-host communication based on the serial bus structure, and ensuring bus communication real-time and reliability.

Description

technical field [0001] The invention relates to a bus interface circuit based on a serial bus structure and its non-destructive bus communication protocol, belonging to the technical field of information network communication. Background technique [0002] The development of electronic information, communication and computer technology has brought great changes to the whole society; at the same time, due to the expansion and development of industrial technology, the application of electronic information, communication and computer technology in factories, buildings and agricultural fields is becoming more and more extensive. and in-depth. Among them, the digital communication between intelligent instruments, controllers, executive agencies and other equipment and the communication with the upper control system are the primary problems, and the field bus is the core technology to solve this problem. [0003] Fieldbus provides basic information transmission and networking com...

AI Technical Summary

Problems solved by technology

The problem brought about by this method is that if there are multiple bus nodes transmitting data on one bus at the same time, there is a high possibility of a low-impedance path between high and low levels, which will lead to logic errors or even short circuits on the bus. burn

A common method to solve this problem is to use a tri-state gate with a "push-pull" output structure to access the bus at the bus node, and control the bus node to transmit data through the polling method of the microcontroller. This method can ensure Only one tri-state gate is in the working state at each moment, while the other tri-state gates are in high-impedance state, but when the number of bus nodes is large, the communication process using the polling method becomes very slow, which does not conform to the field bus Real-time requirements, and this method requires an additional control bus to control the working state and high-impedance state of the tri-state gate

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