Patent ID: 7149939

Claim:
A method of testing functionality of a memory which operates at a high operating clock frequency, comprising: generating test data to form generated test data, wherein said generating occurs within an external testing device; writing at a low operating clock frequency said generated test data into at least one reference memory to form first test data; copying the first test data from the at least one reference memory to at least one memory to be tested at the high operating clock frequency to form copied test data, wherein the at least one reference memory is outside of the at least one memory to be tested and the external testing device; reading the copied test data from the at least one memory to be tested at the low operating clock frequency, said reading done by the external testing device; comparing the copied test data with the generated test data, said comparing done by the external testing device; and indicating, through a functionality-indicating signal, the functionality of the at least one memory to be tested if the copied test data are identical to the generated test data.