Patent · US Expired

Logic circuit with a test capability

US4424581A · kind A · utility

14Cited by
1References
10Claims
0Family size

Assignee

Inventor

Key dates

Filing dateNov 24, 1981
Grant dateJan 3, 1984
Priority date
Expiry dateNov 24, 2001

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F11/27
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A flip-flop circuit receives a portion of a multiple bit output from a combinational logic circuit to be tested, and feeds back a plurality of bits to comprise a portion of the multiple bit input to the combinational logic circuit. The flip-flop circuit includes a plurality of master and slave flip-flops with the master flip-flops being operable in parallel to receive the output from the combinational logic circuit or in series as a shift register, and the slave flip-flops being operable either in parallel to receive outputs from the master flip-flops or in series as a shift register. The occurrence of a fault in a combinational logic circuit can be determined by examining the contents of either the master or slave flip-flops at a particular clock cycle.

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