How CPU's work (was Re: Hi, I'm new...) ard at
p850ug1.demon.co.uk Sun Aug 6 17:28:13 CDT 2006 > Tony Duell
wrote: > >> Hehe... abracadrabra. > > All I can say is that it's
a wonderful feeling when you finally > > understand how a CPU
works at this level. All the magic has gone away, > > everything
makes sense again. > Yeah, CPU's are really very simple. Here's
my half drunken rant about > them. Skip this if you know how
CPU's work. :-) > Basically, CPU's fetch opcodes (instructions)
and data, then decode said > instruction, execute them, and
increment their Program Counter register > (or change it to a
new value), and repeat. The ones with microcode (or > RISC) are
easiest to understand, although you don't get to see the That
very much depends on the CPU. If the CPU is many chips (not a
single package) with microcode in PROMs, there's nothing to stop
you desoldering said PROMs and reading them out. I've done that,
then written a disassembler for the microode instructions and
worked out what was going on. And