Spacecraft uplink, downlink, and intercommunications in a space-qualified ASIC chip set

Abstract

This paper describes the functionality of four application specific integrated circuits (ASICs) developed for the Cassini spacecraft. The four ASICs are used on the spacecraft in the command and data subsystem to receive uplink data, transmit downlink data, and provide intercommunications within the spacecraft via a 1553B bus. Implemented in the ASICs is a portion of the spacecraft uplink and downlink protocol specified in the Consultative Committee for Space Data Systems (CCSDS) standard. The CCSDS standard is a widely used, international standard. The ASICs also provide additional functions often required in a command and data subsystem such as a spacecraft clock, a fault defection unit and DMA. The ASICs, produced in Honeywell's RICMOS technology, are radiation hard, single event upset hard, and highly reliable (Class S). The implementation in space-qualified ASICs of uplink, downlink, and spacecraft intercommunication functions which meet widely used standards is expected to have applications in a variety of spacecraft. >