A gigabit spacewire bus system

Abstract

The invention relates to a gigabit-level SpaceWire bus system. The system comprises a data sending and receiving module, a data buffer module, a SpaceWire protocol processing module and a data processing module; the data sending and receiving module is used for performing format conversion of 16B / 20B coding and parallel data of an optical transceiver; the data buffer module is used for synchronization and data caching of asynchronous clock domains; the SpaceWire protocol processing module is used for receiving and sending bus data, identifying a control code and a data character, updating a protocol state, sending uplink data and addresses and receiving downlink data and addresses; and the data processing module is used for providing a bus interface for the SpaceWire protocol processing module, an external CPU, an external storage and an external register, and providing conversion of bus protocols on AXI and APB chips. According to the gigabit-level SpaceWire bus system disclosed by the invention, the access frequency and time can be reduced; the bus utilization rate can be increased; and high-speed data transmission requirements of spacecrafts can be satisfied.

Description

technical field [0001] The invention relates to a Gigabit-level SpaceWire bus system, which belongs to the technical field of spacecraft high-speed data transmission bus. Background technique [0002] SpaceWire is a full-duplex, bi-directional, serial, point-to-point data bus. In each direction, it transmits encoded data using a pair of differential signal lines. There are thus four signal lines (D+, D-, S+, S-) in each direction, for a total of eight signal lines in both directions. The SpaceWire standard involves six levels of content, namely: physical layer, signal layer, character layer, switching layer, data packet layer and network layer six layers. Among them, the physical layer standard covers four parts: cables, connectors, cable assemblies, and printed circuit board traces (PCB tracks). The SpaceWire cable contains 4 individually shielded twisted pairs inside and is wrapped with a layer of shielding material on the outside. Signal layer standards specify signal...

AI Technical Summary

Problems solved by technology

However, for the bus system with Star-Dundee's SpaceWire IP as the core, the physical medium is cables, and the bandwidth is generally only a few hundred megabytes, which is difficult to reach the gigabit level; secondly, DS coding is essentially one clock with one data. If the transmission rate exceeds 1Gbps, the clock cycle must be less than 1ns, which is very difficult to realize technically, so the actual data transmission rate that can be achieved is only 200Mbps; moreover, the data access interface of the current bus system is 32 bits wide. After completing 4 SpaceWire data characters (1 data character is 8bit data), it needs to access the memory once, resulting in many times of memory access and long waiting time for memory access, so the bus utilization rate is low

Images