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Processor with Second, Test Clock for Electromagnetic Radiation Test in the Presence of Other Processors

IP.com Disclosure Number: IPCOM000045118D
Original Publication Date: 1983-Feb-01
Included in the Prior Art Database: 2005-Feb-06
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Masch, AC: AUTHOR [+4]

Abstract

A data processing system is provided with a second clock that operates at a slightly different frequency from the normal clock. For a test of the processor for electromagnetic radiation, the processor is operated with its second clock. Since the electromagnetic radiation occurs primarily at the clock frequency, the radiation of the processor under test can be distinguished from the radiation of other nearby processors. Alternatively, the clocks of the nearby processors can be changed, and the test can be performed at the normal clock frequency.

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Processor with Second, Test Clock for Electromagnetic Radiation Test in the Presence of Other Processors

A data processing system is provided with a second clock that operates at a slightly different frequency from the normal clock. For a test of the processor for electromagnetic radiation, the processor is operated with its second clock. Since the electromagnetic radiation occurs primarily at the clock frequency, the radiation of the processor under test can be distinguished from the radiation of other nearby processors. Alternatively, the clocks of the nearby processors can be changed, and the test can be performed at the normal clock frequency.

The outputs of the normal clock and the test clock are each connected to a common output through logic circuits that cause switchover between the offgoing clock and the oncoming clock to take place between the fall of the offgoing clock and the rise of the oncoming clock. Thus the changeover from one clock to the other does not affect the operation of the system. The switchover logic is actuated by a manual switch.

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