We have found, by looking at generated code, that the compiler does not preserve the XF flag at the end of interrupt routines. It just does a reti. Sadly this "feature" is not mentioned in the compiler manual. There is a similar problem with the HINT pin flag in ST3. In the test ISR I just had the compiler generate it pushes and pops ST3 without preserving the HINT flag. We have had to use assembler wrappers for any ISRs we want written in C.
Can someone from Ti state if compiled code (not interrupt routines) can ever under any circumstance push or pop ST1_55 or ST3_55 and thus prevent us from altering the XF and HINT flags in ISRs.
Many thanks,
John
