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Processor Checking

IP.com Disclosure Number: IPCOM000083118D
Original Publication Date: 1975-Apr-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 2 page(s) / 35K

Publishing Venue

IBM

Related People

Carnes, ML: AUTHOR [+2]

Abstract

Satisfactory firmware (microcode) and hardware performances are checked for proper operation by program address monitoring. The program address monitoring checks to see whether or not a specific instruction stored in memory is executed within a specified length of time. In this mode, the processor check simply compares the memory address of the instruction being executed as represented by the output of a program counter with a preset value received from the processor circuits.

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Processor Checking

Satisfactory firmware (microcode) and hardware performances are checked for proper operation by program address monitoring. The program address monitoring checks to see whether or not a specific instruction stored in memory is executed within a specified length of time. In this mode, the processor check simply compares the memory address of the instruction being executed as represented by the output of a program counter with a preset value received from the processor circuits.

If the compare is satisfied, the compare circuit supplies a reset signal to the timing counter preventing an alarm signal from being emitted. The timing counter not receiving a reset signal supplies an alarm signal upon reaching a predetermined count. The time duration may be varied by varying preset signal content into the timing counter.

The processor circuits operate with the memory through the program counter for fetching a sequence of instructions, as well as directly for fetching operands. The memory supplies the fetched instructions and operands to the processor circuits. Switch W, at the input portion of the compare circuit, is selectively switched under process control between monitoring the instruction address of the program counter, or another set of signals received from the processor circuits at terminal A.

Terminal A signals may be any specified memory address, or any other marker type of signal to be generated by processor sequences being executed by the pr...