20 Jul
2016
20 Jul
'16
10:42 a.m.
On Jul 20, 2016, at 1:34 PM, Cameron Kaiser
<spectre at floodgap.com> wrote:
What I meant is that I had no idea such things existed. Very curious. Learn something
new every day. What do they use this for?
The closest to microcode I'd ever heard of before is the "epicode" in Alpha.
Or was that Prism? Anyway, a DEC RISC architecture where some privileged stuff was done
in code running in a corner of the chip. Not actual microcode because it was essentially
the standard instruction set, somewhat extended and running in a special processor state.
paul
Also, RISC does not use, or need, microcode.
I'm not sure what you mean by this, but (for example) many POWER
implementations have microcode (example: the 970/G5, which is descended from
POWER4).