TMS320F28377S: F28377s CLA RAM diagnostic

Jordan,

This app note gives more details on RAM test on this device. 

The LSx RAM has parity coverage to detect errors in real time when the location is read.  This would apply to reads that the CLA does when it fetches its program code in the above case.  Parity has ability to detect odd number of bit errors in each word, so that baseline coverage would be 50% detection rate.  However, I think the likelyhood of multiple bit errors in a single word caused by a soft error even would not be so high.  Can you see if the Diagnostic XLS/FIT estimator gives some ideas on this for customer system?  This would be no different than the coverage on LSx RAMs if the CPU were using it for code; so if customer has some baseline on how the C28x coverage is handled we can apply it here as well.

If the customer requires higher coverage, in a run time scenario, if the  LSx memory is used as CLA program RAM, the C28x CPU is blocked from accesses.  If we want to test this RAM with the C28x processor we would need to copy the code stored there to another memory, unblock the C28x, test the RAM, then copy the code back and then set the access back to CLA Program.  Customer would need to weigh doing this in real time with the control loop frequency if there is time to take the CLA offline to perform this test.                                                                                                                                                                                                                                                                                                                  

Best,

Matthew

Thanks Matthew.

Let's have a discussion with customer and feedback you later.

Maybe, we'll use F28377D to do it, instead of F28377S.

Br, Jordan