AnsweredAssumed Answered

Byte wide access to OCOTP->LOCK address seems to hang the CPU...

Question asked by Ed Sutter on Apr 21, 2020
Latest reply on Apr 29, 2020 by Ed Sutter

Hi,

I'm working on an MIMXRT1060-EVK.  I'm doing some work with the OCOTP and I accidentally read from address 0x401f0400 (LOCK register) with a byte-wide access.  Clearly this is illegal.  My firmware catches all exceptions, but what I noticed was that my running program just hung (i.e. no longer responsive).  So, I attached my Segger JLINK and ran the [illegal] code again hoping that I could halt the core to see where the code was after that access (thinking maybe my exception handling was the problem).  I got a response from JLINK:  

 

**************************
WARNING: CPU could not be halted
**************************

Is this expected?  What is the state of the CPU if JLINK can't halt it?  Shouldn't that illegal access have caused the processor to at-least take a hard-fault exception?

Any thoughts?

Outcomes