AnsweredAssumed Answered

LPC845 BOD Power Up

Question asked by Helder Parracho on Mar 19, 2018
Latest reply on Jul 31, 2018 by Hanson He



Working with the latest MCUXpresso and a LPCXpresso845MAX Rev.A board.

I am experiencing a strange problem with my board when enabling Brown-Out detection.

As soon as I power up the BOD peripheral my program stops working (not power related issue).


LPC_SYSCON->PDRUNCFG &= ~(1 << 3);


If I try it in a debug session the debug terminates in the same instruction with the error:

16: Target error from status-poll
Wire ACK Fault in DAP access
16: Target error from status-poll: Ee(FF). Redlink interface error 255.
Debugging context: lpc845 LinkServer Debug


After this I lose access to the chip and can only recover it by entering ISP, mass erase and flash it again.

I have discovered (by pure luck) that if I enable the ACMP (Analog comparator) first and then the BOD, everything works fine. I can even disable ACMP immediately after. I have also noticed that BOD reset enable (LPC_SYSCON->BODCTRL bit 4) starts enabled after reset and not disabled as the manual states. (The manual and datasheet are full of typos and errors, a shame really...)


Any thought on this issue? Thanks.