Self-Testing of Embedded RAMs

A design-for-testability method for embedded RAMs is presented. This method combines both selftest and scan techniques. A simple march test pattern is used in self-test to detect all hard failures in the RAMs. A scan technique is used to detect stuck-at and bridging faults in the comparator and data lines, and to diagnose single stuck-at faults in the RAMs. To obtain better fault coverage, a modified pseudo-random pattern generator is used as an address generator. The overhead is very low and the test time is short.