Diagnostic apparatus for a data processing system

Details Diagnostic apparatus for a data processing system Diagnostic apparatus for a data processing system

1987-04-20

1988-10-25

Smith, Jerry

Excavating

324 73R, G01R 3128

Patent

active

047808748

ABSTRACT:
A level sensitive scan design (LSSD) diagnostic apparatus for a data processing component. Each scan unit in a shift register chain comprises a plurality of level sensitive elements, e.g., data latches, which transfer signals from their input terminals to their output terminals in response to a "Phase B" pulse train. A multiplexer is connected to each data latch for communicating run data to the input terminal of each data latch in a normal mode of operation. In test mode, the multiplexer communicates signals from the output terminal of one data latch to the input terminal of an adjacent data latch, so that the data latch signals are serially communicated through the resulting latch chain.
In order to prevent the test data from propagating uncontrollably through the serially connected latches, each multiplexer includes a test latch disposed between the test data input of the multiplexer and the output terminal of the preceding data latch in the chain. The test latch is controlled by a "Phase A" pulse train signal which is interleaved with the phase B pulse train.

REFERENCES:
patent: 4509008 (1985-04-01), DasGupta et al.
patent: 4513418 (1985-04-01), Bardell, Jr. et al.
patent: 4519078 (1985-05-01), Komonytsky
patent: 4649539 (1987-03-01), Crain et al.
patent: 4698588 (1987-10-01), Hwang et al.
patent: 4710933 (1987-12-01), Powell et al.
patent: 4718065 (1988-01-01), Boyle et al.

Affiliated with

Also associated with

Rating

Diagnostic apparatus for a data processing system does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Diagnostic apparatus for a data processing system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Diagnostic apparatus for a data processing system will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2273768