Browse Prior Art Database

BI-MODALLY SHIFTABLE SCAN CHAIN

IP.com Disclosure Number: IPCOM000014236D
Original Publication Date: 2000-Jan-01
Included in the Prior Art Database: 2003-Jun-19

Publishing Venue

IBM

Abstract

Title: Bi-modally Shiftable Scan Chain Problem: Scan based designs depend on serially loading and unloading the system latches or Shift Register Latches (SRLs) to support the structural test methodology and interface with the logic within the device. When the scan chain is defective or "broken", basic access to the device is limited and quick accurate diagnosability becomes a severe problem. This disclosure proposes a solution for diagnosing stuck-at scan chains to the failing Shift Register Latch (SRL) by bypassing the defective portion of the scan chain without impacting system performance. This logic fault localization enables Physical Fail Diagnostic (PFA) to identify the root cause of the defect. Solution: