| 摘要 |
The present invention is directed to a system and method for improving transition delay test coverage through use of enhanced flip flops (ES flip-flops) for a broadside test approach. Each ES flip-flop includes a two port flip-flop including a first flip-flop and a second flip-flop. A separate control input (ESM) which is not time critical is used to select a multiplexer of the second flip-flop. Thus, the ES flip-flops do not require a fast signal switching between launch and test response capture or an extra clock signal. Various enhanced scan modes may be selected via a combination of SEN and ESM. Moreover, only a heuristically selected subset of scan flip-flops may be replaced with the ES flip-flops so as to minimize the length of a scan chain as well as the logic area overhead. The present invention provides high TDF coverage under the broadside testing.
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