Yokemate of Keyboards
Posts: 4977 from 2009/1/28
From: Delaware, USA
Quote:
Andreas_Wolf wrote:
>> the 68060 is completely hard-wired while the 68040 and prior use microcode.
> I don't believe this to be true of any 68k processor, but we can check.
"MC68060 [...] is all hardwired - there is no microcode in it."
http://www.faqs.org/faqs/motorola/68k-chips-faq/
From the Freescale website:
"The Motorola 68K family consists of a wide range of members from the micro-coded MC68000 to the super-scalar, hard-wired MC68060."
http://www.freescale.com/files/32bit/doc/reports_presentations/MC680X0OPTAPP.txt
From Motorola's Jim Reinhart:
"the 060 execution units are fully logic driven (i.e. no microcode)"
http://www.verycomputer.com/154_1d1b5950dff465d3_1.htm#p4
Thanks Andreas,
That really confirms what I've heard over the years (that there conflicting views on this).
My information came directly from Motorola engineering in the early '90s.
So, as we were using the 68000, getting ready to use the '020, and the '030 was on the horizon (but the '060 was long off), I'd be willing to say the 68K family is entirely microcoded.
BUT...here is the problem, there is no way to confirm anything.
The structure of these chips is totally "black box".
We have diagrams showing us the logical parts and we have the instruction set, programming modes, and other useful info but no real info on the actual logic.
"Never attribute to malice what can more readily explained by incompetence"
