Allocation techniques for reducing BIST area overhead of data paths

Built-in self-test (BIST) techniques modify functional hardware so that a c hip has the capability to test itself. A prime concern in using BIST is the area overhead due to the modification of normal registers to BIST register s. This paper proposes register and interconnect assignment techniques that address the BIST area overhead issue during high-level synthesis. A minima l intrusion BIST methodology is employed where a subset of the functional r egisters are modified to be BIST registers. Depending on the BIST functions performed (test pattern generation and/or test response compression) and t he concurrency of the functions, four types of BIST registers with varying costs are used. Data path allocation techniques are presented that (1) maxi mize the sharing of BIST registers between modules, and (2) minimize the nu mber of expensive BIST registers that are essential for minimal intrusion B IST of a data path. The designs synthesized by our techniques have the same number of functional modules and registers as those synthesized using trad itional approaches but require significantly lower BIST area overhead.