DESIGNATED FAIL NUMBER ADDRESS SEARCH CIRCUIT OF MEMORY TESTER

摘要

PURPOSE:To search an X-address or a Y-address having a fail address more than a prescribed value as a relief address in short time. CONSTITUTION:A memory 2 stores fail data in the same address as the fail address of a memory for tested object. The memory 2 is read at high speed by an address signal from an address generator 1. A comparator 4 adds fail data which is read from the memory 2 as to the same X-address or the same Y-address and compares an added value with the prescribed value stored in a register 3. The comparator 4 outputs a write enable signal to a memory 5 when the added value of fail data is large. The memory 5 stores the address signal outputted from the address generator 1 as data at timing when the write enable signal is inputted.