Patent ID: 6459638
Filing Date: 2002-10-01
Classification: G11C

Abstract:
A built-in programmable self-diagnostic method for finding functional faults in a static random access memory (SRAM) unit, comprising the steps of:selecting a test mode or an analysis mode; reading out a test instruction according to the mode chosen; determining if the test instruction is an end of reading instruction; sending out a test termination signal if the test instruction is an end of reading instruction; executing a test instruction from a test instruction set if the test instruction is not an end of reading instruction; determining if the execution of test instructions of the test instruction set is completed; returning to the step of reading out a test instruction according to the mode chosen if the execution of test instructions of the test instruction set is completed; determining if the results of executing the test instruction set indicate any errors if the execution of test instructions of the test instruction set remains unfinished; returning to the step of executing the test instruction of the test instruction set if the results of executing the test instruction set indicate no errors; and sending out an error signal and an error operation protocol so as to find the fault location in the SRAM unit and returning to the step of executing the test instructions of the test instruction set if the results of executing the test instruction set indicate some errors.