Built-in self-test for multi-port RAMs

Most multi-port memory BIST algorithms treat the memory as multiple individual single-port memories and test each independently using the algorithms developed for single-port RAMs. A major problem with this approach is the lack of coverage for multi-port specific defects, such as inter-port interferences due to shorts across ports. This paper proposes a novel BIST algorithm for multi-port RAMs that detects both The conventional single-port faults as well as inter-port shorts. The proposed algorithm performs a conventional single-port test such as MARCH (1991) or SMARCH (1990) on one port of the memory and simultaneously performs an inter-port test on all other ports. The algorithm does not impose any extra test time and requires the addition of only a few gates to a conventional single-port BIST controller, independently of the size of the memory.