Method to dynamically inject errors in a repairable memory on silicon and a method to validate built-in-self-repair logic

Abstract

An error injection system of a built-in self-repairable memory system renders the redundant spare columns of the repairable memory accessible to built-in self-test (BIST) read and write operations. To this end, the error injection system selectively injects fault data at one or more locations of the main memory during a BIST sequence, causing the BIST controller to issue a repair instruction that allocates one or more spare columns as replacement memory areas for the presumed faulty main memory locations. Thereafter, BIST read/write operations directed to the main memory locations will be performed on the allocated spare columns, thereby allowing the spare columns to be validated as part of the BIST. Injection of fault data to the main memory locations in this manner can also facilitate validation of the built-in self-repair logic by verifying the repair instruction codes that are generated in response to the injected faults.