Patent · US Expired

Pseudo-memory circuit for testing for stuck open faults

US4742293A · kind A · utility

16Cited by
2References
15Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 6, 1987
Grant dateMay 3, 1988
Priority date
Expiry dateApr 6, 2007

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01R31/318544
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A method and apparatus are disclosed for testing for stuck- open faults in integrated circuits (10) having a plurality of combinational logic devices (18, 20). The apparatus includes a chain of shift register stages (22), with each stage including at least two latches (L1 and L3). The bits of an initialization test are shifted down the shift register and loaded into one of the latches (L3), while the bits of a detection test pattern are subsequently shifted down the chain and stored in the other latch (L1). A multiplexer (50) is provided for selecting one of the outputs from the two latches (L1, L3) so that the initialization test pattern and then the detection test pattern can be quickly applied to the combinational logic so as to minimize hazards which could invalidate the test results.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.