Abstract: A method for verifying the accuracy of memory testing software is disclosed. A built-in self test (BIST) fail control function is utilized to generate multiple simulated memory fails at various predetermined locations within a memory array of a memory device. The memory array is then tested by a memory tester. Afterwards, a bit fail map is generated by the logical-to-physical mapping software based on all the memory fails indicated by the memory tester. The bit fail map provides all the fail memory locations derived by the logical-to-physical mapping software. The fail memory locations derived by the logical-to-physical mapping software are then compared to the predetermined memory locations to verify the accuracy of the logical-to-physical mapping software.

Abstract: A method and apparatus for testing a write function of a dual-port static memory cell during a concurrent read/write cycle on a memory cell is disclosed. A memory cell of a dual-port static memory is read via a first port of the memory cell. After the read operation, the standard bitline restore operation that normally occurs after a read or write operation is suppressed from occurring on the bitlines for the first port. Then, the memory cell is read again via the first port at the same time the memory cell is being written via a second port with a logical data value that is opposite to the logical data value being read from the first port. After the completion of the write operation, the bitlines for the first and second ports are restored by a bitline restore operation. Finally, the logical data value in the memory cell is verified for its correctness.

Abstract: A testing method and device for detecting the existence of “stuck-open”, faults within static decoder circuits of a SRAM. The device and method make use of a novel pattern that fully tests static decoders used with an SRAM integrated circuit. The test pattern is selected so as to cause a transition on each parallel FET in a decoder circuit. The test pattern simulates multiple random accesses to the SRAM by modifying the traditional sequential, unique address pattern. The invention uses a two-dimensional pattern in that it separately tests rows and column decoders. In the first part of the test the input address to the column decoders is held constant while the row decoders are cycled through two sets of N iterations where N is the number of row address bits to be decoded. During the second part of the test the input address to the row decoders is held constant while the column decoders are cycled through two sets of M iterations where M is the number of column address bits to be decoded.

Abstract: A method and apparatus for testing a write function of a dual-port static memory cell during a concurrent read/write cycle on a memory cell is disclosed. A memory cell of a dual-port static memory is read via a first port of the memory cell. After the read operation, the standard bitline restore operation that normally occurs after a read or write operation is suppressed from occurring on the bitlines for the first port. Then, the memory cell is read again via the first port at the same time the memory cell is being written via a second port with a logical data value that is opposite to the logical data value being read from the first port. After the completion of the write operation, the bitlines for the first and second ports are restored by a bitline restore operation. Finally, the logical data value in the memory cell is verified for its correctness.