Implementing enhanced scan chain diagnostics via bypass multiplexing structure

A system for implementing enhanced scan chain diagnostics comprising:

• a scan chain;
• said scan chain partitioned into a plurality of separate partitioned chains with bypass multiplexers for implementing enhanced scan chain diagnostics;
• said bypass multiplexers having independent controls enabling scan data to be routed through multiple different independent scan paths;
• providing a processor, said processor performing the steps of
• routing scan data through a combination of said chain scan and said separate partitioned chains and acquiring information used for scan failure isolation to enable pinpoint identification of stuck-at-zero (SA0) and stuck-at-one (SA1) faults in the scan chain including
• running full SA0 and SA1 scan tests;
• responsive to identifying a fail in the full scan results, running separate partitioned SA0 and SA1 scan tests for each of plurality of separate partitioned chains;
• responsive to identifying a fail in a respective separate portioned chains, running the full SA0 and SA1 scan tests, moving the fail to a passing scan path section;
• responsive to identifying a required failing partitioned chain scan bypass test, scanning a next passing partitioned chain results for a number of number of cycles to point to respective fail location.