Patents

patent US5778171A

Processor interface chip for dual-microprocessor processor system

Also published as:

A processor interface chip and a maintenance diagnostic chip are provided coupled with two microprocessors designed to be run in tandem. The processor interface chip includes logic for interfacing between the microprocessors and a main memory, logic for pipelining multiple microprocessor requests between the microprocessors and main memory, logic for prefetching data before a microprocessor issues a read request, logic for allowing a boot to occur from code anywhere in physical memory without regard to the microprocessors' fixed memory location for boot code, and logic for intelligently limiting the flow of interrupt information over a processor bus between the microprocessors and the processor interface chip. The maintenance diagnostic chip includes logic to halt either of the microprocessors if an error is detected, and read out the state of the microprocessors and a secondary cache attached to the microprocessors, before the state of the microprocessors at the time of the fault changes to a different state which might hide evidence of the cause of the fault.

Inventors

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https://patentimages.storage.googleapis.com/a0/d0/21/f355df6705a031/US5778171.pdf

Current Assignee

Hewlett-Packard Development Co LP

Original Assignee

Tandem Computers Inc

Priority date

1993-07-06

patent Australia 1996068009 (lapsed)

An interrupt processing apparatus

Inventors

Effective date of patent

1994-07-04