Ahlan Marriott

Using WDEBUG with MCF5235

Discussion created by Ahlan Marriott on Apr 5, 2012
Latest reply on Apr 12, 2012 by Ahlan Marriott



I am try to generate an interrupt when a particular area of memory is written to.

The debug  support feature of the MCF5235 seems simple enough as described in chapter 32 of the RM

however I can't get it to work.

Perhaps I have misunderstood or missed something.

I would greatly appreciate if someone who uses this feature can tell me what I am doing wrong.


I set the debug control registers using the WDEBUG (A1) command where A1 contains the address of  64 bit long word aligned record. The first 16 bits contain 0x2C80 plus the register number and the next two 16 bit words contain the MSW and the LSW of the value to be written to the register.


In my code I first set the TDR to zero.

Then set ABLR to the start address of the block of memory to be watched

and the ABHR to the last address.

I then set TDR to 0x8000_2008 (EBL, EAR first level trigger and TRC=10 - Debug interrupt.


When I write into the memory area covered by ABLR/ABHR nothing happens.


Has anyone any ideas what i am doing wrong?


Best wishes,