TEST DEVICE FOR SEMICONDUCTOR MEMORY

摘要

PROBLEM TO BE SOLVED: To prohibit over-write-in and over-erasure of data with a bit unit in testing a function of a memory device such as a flash memory or the like. SOLUTION: A logic comparing circuit 50 which is provided individually for each bit on a bit line of an address to be tested of a DUT 4 judges coincidence/uncoincidence with a bit unit, when it coincides, a bit coincidence signal is held in a loop circuit L and outputs it during retry, when a bit coincidence signal is outputted, a bit control driver 60 prohibits write-in operation and erasure operation for the bit.