I am fairly new to ARM. The documentation for the Instruction Set is pretty lacking. I am looking for any documents available that will show all the instruction set of the ARM, and especially, showing how the flags are affected. As it is I have discovered it to be very strange that the carry flag acts as it should with the ADD instruction but is the opposite for the SUB instruction. Is there anyone out there who can shed some light on this issue? I have documentations from ST, Atmel, and ARM on the instruction set but now of them explains how the carry flag is affected by the SUB instruction.
In reading it I must thank you again Roger for the link. That is a really well documented explanation of the ARM instruction set and has been very helpful. I am one of those die hard Assembler Programmers. I am currently working on Large Number Arithmetic (128 doubles=256 words= 512 bytes). The behaviour of the flags is critical especially to design compact and fast codes. Hopefully if I am successful I will be able to implement a crpyptographic system all in assembler. Lee