Transmission method of isochronous data packet in as5643 bus

Abstract

The invention brings forward a transmission method of an AS5643 bus including an isochronous data packet, and aims at providing the transmission method that a 'soft' uncertainty problem caused by interleaved transmission of the isochronous data packet and an asynchronous data packet is avoided, and an AS5643 remote node which does not support isochronous transmission is compatible. The invention is realized via the following technical scheme: one data transmission frame period of the bus is divided into two parts of an isochronous time slot and an asynchronous time slot. The isochronous time slot comprises multiple cycle periods enabling the node to send multiple same channel isochronous data packets. The number of cycle start packets sent in the isochronous time slot is determined by time planning of the isochronous time slot. In the isochronous time slot, only the isochronous packets are transmitted; correspondingly, in the asynchronous time slot, only asynchronous packets are transmitted. Receiving and sending deviation time of the asynchronous packets relative to STOF packets is arranged in the asynchronous time slot. Periodical sending of the cycle start packets is closed in the asynchronous time slot. A mater control node (CC node) controls periodical sending and forbidden sending of the cycle start packets.

Description

technical field [0001] The invention relates to an optimized transmission scheme including isochronous and asynchronous transmission in the AS5643 bus. Background technique [0002] IEEE-1394 is a high-performance serial bus technology (also known as Firewire) first proposed by Apple (Apple). In 1995, IEEE formulated and promulgated the IEEE-1394 standard. At present, this bus technology has been widely used at home and abroad. Applications. The serial bus can support isochronous and asynchronous transmission at the same time, can provide gigabit data transmission rate, and does not need the host to control. With the development of embedded system technology, the requirements for the system bus are getting higher and higher. Electronic system designers are faced with the pressure brought by high-speed, real-time, long-distance, and easy-to-connect requirements. IEEE-1394 serial bus is based on Its high speed, isochronous / asynchronous transmission mode and flexible topology...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to solve the problem that the existing AS5643 bus transmission of isochronous packets will bring uncertainty, and to provide a method that can avoid the interleaved transmission of isochronous packets and asynchronous packets, avoid the occupation of bus resources by cycle start packets, and is compatible and does not support isochronous transmission. The optimized transmission scheme of the AS5643 remote node can introduce isochronous transmission without destroying the determinism of the AS5643 bus in advance

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