TEST METHOD AND CIRCUIT OF ASSOCIATIVE MEMORY CIRCUIT AND ASSOCIATIVE MEMORY CIRCUIT WITH REDUNDANCY FUNCTION

摘要

PROBLEM TO BE SOLVED: To easily test a CAM (associative memory) by automatically generating the test pattern of inspection data. SOLUTION: An inverter INV1 inverts a scan signal SOD1 outputted from a scan path and gives it to 1-input terminal of a selector SEL1. The scan input SIDI is obtained by inverting the scan output of a scan flip flop SFF-DDI2. Therefore, when testing a CAM100, a test signal CAMTEST is set to '1', thus cyclically generating input signals D10, D11, and D12, namely initial value of retention data (0, 0, 0) →(1, 0, 0) → (1, 1, 0) → (1, 1, 1) → (0, 1, 1) →(0, 0, 1) → (0, 0, 0) →... and hence eliminating the need for consecutively creating inspection data in advance and giving them to each scan flip flop by shifting.