Daniel Rogers

External read not working

Discussion created by Daniel Rogers on Oct 31, 2006
Latest reply on Oct 31, 2006 by CrasyCat
I have a periperal decleared called pGraphicCTRL.
 
Writing data to this address works fine.
 
but I wont to do this.
 
pGraphicCTRL = pGraphicCTRL | Graphic_CD
 
This should generate a read and then a write on the data bus. I only get a write.
 
if I change it to
 
cControl = pGraphicCTRL;
pGraphicCTRL = cControl | Graphic_CD;
 
I still only get a write and if I step though the code the cControl = pGraphicCTRL line is not compiled in.
 
Why?
 
Is this a optimizer thing if so its great job but not this time. What if my signal lines are different.
 
How do I get around it.
 
Can I turn the optimizer off?
 
Daniel

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