High-level variable selection for partial-scan implementation
Frank F. Hsu, Janak H. Patel · 1998
In this paper, we propose a high-level vatiable selection jor patiial-smn approach to improue the testability oj digital systems.The testability oj a design is evaluated at the high level based on previously pToposed contTol[abi!ity and observability mwuTes.A testability gruding technique is utilized to measure the Telative testability improvement in a design as the result oj making a subset of the variables jully controllable and observable.The variables that cause the gTeatest testability improvement aTe selected, and the selection pTocess is perjormed incrementally until no fiTtheT testability improvement can be achieved.Then the TegisteTs that correspond to the selected variables aTe placed in the scan-chain jor partial-scan implementation.The qerimentul Tesults shows that the vatiable selection approach.produces partial-scan implementations that cun achieve high jault coveTage, while the logic oveTheads are jairly low.