Method of diagnosable scan chain

Abstract

A method for implementing a scan chain to test a semiconductor including obtaining an initial structure of the scan chain, determining, according to function modules of the semiconductor corresponding to scan registers on the scan chain, a first scan register pair with backward dependency, adjusting a structure of the scan chain such that the first scan register pair with backward dependency becomes a scan register pair with forward dependency, when a fan-in scan register in the scan register pair with backward dependency belongs to the key subset of the fan-out scan register in the first scan register pair with backward dependency, and determining a key subset of a fan-out scan register in the first scan register pair with backward dependency, wherein when all fan-in scan registers in the key subset reflect a same logic value, an output logic value of a function module connected to the fan-out scan register is fixed.