Multi-type SRAM Test Structure with an Improved March LR Algorithm

With the high-density integration of chips, the use of multi-type SRAM memory is becoming more and more extensive, which also brings great challenges for the testing of chips. Traditional MBIST is usually also achieved by using EDA tools, which makes it difficult to test multi-type memory directly. In this paper, a two-layer FSM PMBIST test structure is proposed, with the outer FSM controls to cut the effective address and data, which can realise the efficient testing of multi-type memory, and the inner FSM combines LFSR and integrates the improved March LR algorithm, which can achieve 100% coverage of the static dual-cell coupling faults. Finally, the simulation of the 55nm process verifies the normal function and good performance of the test structure.