17 Sep
2016
17 Sep
'16
10:10 a.m.
On 09/17/2016 09:23 AM, Eric Smith wrote:
I don't know what the width of the TMS9900 ALU is,
but I'm pretty
sure it's not bit-serial, as an add instruction only takes 14 clock
cycles, including four memory cycles. I'd be very surprised if the
ALU isn't either 8 or 16 bits, though 4 might be possible.
Possibly someone is confused by the bit-serial "CRU' I/O space, but
that is unrelated to the ALU width.
Could very well be--I'm just going by other's appraisals of the
architecture.
But there were some "8 bit" MPUs with bit-serial ALUs, so the question
is still valid.
--Chuck