Patent · US Expired

Scan test method, integrated circuit, and scan test circuit

US7475306B2 · kind B2 · utility

0Cited by
4References
14Claims
0Family size

Assignee

Inventor

Key dates

Filing dateOct 28, 2004
Grant dateJan 6, 2009
Priority date
Expiry dateMar 15, 2025

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01R31/318566
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A scan test method of an integrated circuit including a combinational circuit and flip-flops forming a scan chain is disclosed. The method first sets an initial test value to the flip-flops forming the scan chain by serial scan input. Then, it repeats a capture operation and a feedback shift operation. The capture operation captures an output of the combinational circuit, to which a value set to a flip-flop has been applied, by another flip-flop. The feedback shift operation feeds an output of the scan chain back to an input side of the scan chain for re-input during a shift operation in the scan chain. Finally, it compares an output of the scan chain with an expected value.

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