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Analytical Representations of Digital Signals

IP.com Disclosure Number: IPCOM000049282D
Original Publication Date: 1982-Apr-01
Included in the Prior Art Database: 2005-Feb-09
Document File: 2 page(s) / 51K

Publishing Venue

IBM

Related People

Shields, DJ: AUTHOR

Abstract

A tester prints easily analyzed representations of digital signals present in a tested device. Only those symbols indicating signal conditions falling within selected criteria are printed.

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Analytical Representations of Digital Signals

A tester prints easily analyzed representations of digital signals present in a tested device. Only those symbols indicating signal conditions falling within selected criteria are printed.

Test leads 102 connect to a large number (for example, 128) of test points 101 on a tested device 100. A multiplexer 103 and analog to digital converter (ADC) 104 connect the test leads 102 to a digital data processor 105. In processor 105, registers hold prespecified information which identifies selected test points, a signal level for each selected test point and other time-dependent quantities. Each test point is monitored and, if the time criteria are met, the signals at the test point cause a visual symbol to appear at a display 106. The display provides a printed record 107 showing the number of changes in signal magnitude for each signal from an active test point by a sequence of symbols indicating by its values, and its physical displacement on the record, the directions of signal magnitude changes, and the number of signal transitions that occurred during a given time period.

A header section 600 designates, for every one of the input line numbers 101 preselected for analysis (#1, #5, . . . #128). a particular signal type, number, name, active level, and initial level. For example, line number 009, named T9, is a signal type 1 and is initially at a plus level which is designated as an "up" active level. Signals are graphica...