5.4.3 MBIST Overview

The dsPIC33A device family features a (data) Memory Built-In Self-Test (MBIST) that has the option to be run at start-up or run time. The memory test checks that all memory locations are functional and provides a pass/fail status of the RAM that can be used by software to take action if needed. If a failure is reported, the specific location(s) are not identified.

The MBISTCON register contains control and status bits for BIST operation. The MBISTDONE bit (MBISTCON[7]) indicates if a BIST has been run since the last Reset, and the MBISTSTAT bit (MBISTCON[4]) provides the pass/fail result. BIST is always clocked from an independent, non-configurable PLL, resulting in a 200 MHz clock rate unless CLKGEN4 is modified.