Verification and Testing Considerations of an In-Memory AI Chip

In-memory computing is a propitious solution for overcoming the memory bottleneck for future computer systems. In this work, we present the testing and validation considerations for a programmable artificial neural network (ANN) integrated within a phase change memory (PCM) chip, featuring a Nor-Flash compatible serial peripheral interface (SPI). In this paper, we introduce our method for validating the circuit components specific to the ANN application. In addition, high-density in-memory multi-layer ANNs cannot be manufactured without testing and repair of the memory array itself. Therefore, design for testability (DFT) features commonly used in commodity or embedded memory products must be maintained as well. The combination of these two test/characterization steps alleviates the need to test the actual inference functionality in hardware.