Test circuit and method for refresh and descrambling in an integrated memory circuit

摘要

A semiconductor memory device and method is shown in which a built-in system test (BIST) circuit determines, based upon the test algorithm and the refresh requirements of a DRAM memory cell array, a refresh point address where the BIST circuit performs a refresh operation on the test data in the memory cell array when the test address reaches the refresh point address. Another embodiment of a semiconductor memory device and method is also shown in which a BIST circuit descrambles the test address and test data before input to a memory circuit which includes address and data scrambling circuits such that the logical test address and test data generated according to a test algorithm matches the physical address and data in the memory cell array.