ALLEN NANCE

STOP mode on MCF523x

Discussion created by ALLEN NANCE on May 2, 2007
Latest reply on Nov 1, 2007 by Guest
Hello Coldfire Group:
 
I am having trouble getting my 5232 part to go into low power stop mode.
I set the LPCR regsiter to 0xC8.
I set the LPICR register to 0xF0.
I issue the STOP instruction with a 0x2700 following.
 
I do enter the STOP instruction because execution halts. I am at the STOP
because when I am on the BDM and I halt, my PC is right after the STOP.
But the CLKOUT is still running and the current does not fall much.
 
The documentation says that CLKOUT should stop when the STPMD bit in LPCR is hi.
I have read back the registers and all seems OK.
The LPICR reads back as oxFF and resets to 0x0F. Not sure why that is since the manual
says that it defaults to 0x00.
 
It seems that I am entering STOP but it is not turning off clocks to the CORE, etc.
It is like the ENBSTOP bit is not set in the LPICR register.
 
Any ideas.
 
Thanks,
Allen

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