TMS570LS3137: nERROR LED

If I am reading the datasheet correct these are my sources for nERROR.

I have found that this is occurring in 2 places during system self test.

1- When a 2-bit Error is forced during fmcECCcheck.

2- When the CCM is put into Error Forcing Mode and Self-Test Error Forcing Mode during ccmSelfCheck.

Hi Aaron,

The nERROR is pulled low intentionally when performing the selftest.

QJ,

I am trying to find all the places it is pulled low because I do not want this to occur.

Is there a way to disable the self test from pulling nERROR low?

Hi Aaron,

The self-test function should clear the error flag in ESM status register and also reset the nERROR pin if the nERROR is pulled LOW. 

Is the nERROR LED on your board turned off after code jumps to main()?

Yes it is turned off. My problem is that is the way I am using nERROR. If it is pulled low in my setup, then a PORRST will occur.

No, nPORRST won't occur.

I have external hardware that will cause a nPORRST if a nERROR occurs.

Ok, this is an issue. The device which monitors the ESM nERROR signal be able to detect the nERROR pulse width. If the pulse (LOW) width is reach to a threshold for example 1ms, the device pulls the nPORRST signal to LOW. If the pulse (LOW) width is shorter than the threshold, the device doesn't pull the nPORRST to LOW. The threshold should be programmable.

In MCU side, the nERROR signal should be reset by writing 0x5 to ESKEKR immediately after the diagnostic test.