9 Nov
2007
9 Nov
'07
3:15 a.m.
So what's your thoughts on the 8088? 16-bit
registers, 8-bit data path
(but with 16-bit addressing). Is it a 16-bit CPU or an 8-bit CPU?
ALU and internal data path are 16 bits. It's essentially an 8086
multiplexed down to an 8 bit external data bus. That makes it a 16
bit processor in my book, albeit a crippled one. For the same reason
a MC68008 is a 16 bit processor in the same way that the MC68000 is.
The Z80, on the other hand, has an 8 bit ALU and 8 bit internal data
path, but has 16 bit registers and 16 bit address math and a 16 bit
address bus. That makes it a 8 bit processor.
For MC6809, I don't know enough of the internals to make a judgement.
I'd guess that it's got an 8 bit ALU and 8 bit internal data paths,
but I'm not sure.
Eric