Hi all. I'm using a modified 8051 cpu, and it don't have some instructions (in this case MUL). In Keil IDE, when I do some like: foo = bar << 1; Compiler translate as: MUL AB And it produce a reset of the software. My question is very simple: how I do to indicate the compiler that not to use that instruction? Thanks.
in ancient times when embedded was done with a minicomputer (visualize a chip weighing 40 pounds) there was, at least, one brand where the "economy model" missed some instructions the "full model" had. In tbe "economy model" the unsupported instructions trapped to an ISR where you installed a piece of company provided software that emulated the missing instructions. I recall another case where we handled some atomicity issues by replacing a call with an invalid instruction, the trap disabled all interrupts for the time "the code called" processed.
Erik