A Software-Based Self-Test methodology for on-line testing of data TLBs

For small memory arrays that usually lack Memory Built-In Self-Test (MBIST), such as Translation Lookaside Buffer (TLB) arrays, Software-Based Self-Test (SBST) can be a flexible and low-cost solution for on-line March test application. In this paper, an SBST program development methodology is proposed for on-line testing of data TLB (D-TLB), both for data (SRAM) and tag (CAM) memory arrays. The SBST methodology exploits existing special purpose instructions that modern ISAs implement to access the TLBs for debug-diagnostic purposes, termed hereafter Direct TLB Access (DTA) instructions, as well as, the trap handler mechanism.