24 Jul
2006
24 Jul
'06
2:20 a.m.
woodelf schrieb:
Chuck Guzis wrote:
The cost
for two additional 74s182 (usable instead of am2902) is not
very high,
but there is a price in glitches and reduced clock frequency involved
when propagating
a ripple carry over 5 units (=20bit). You won't find the ripple carry
effect unless you
feed the ALU with certain pathological patterns.
You might also find the Mick&Brick book worthwhile for your enterprise.
On 7/23/2006 at 11:52 PM woodelf wrote:
You didn't mention how "vintage"
your ALU is going to be (I'm
assuming this
is a vintage design and not an FPGA). Are you using something like the
74S481 4-bit slice or are you going for something from the 29xx family?
I was planning to use generic 2901's and LS parts other than PROM.
Ripple carry for the ALU is used since this is only 5 slices. Since I am using a 6809 style clock I hope to get about 1.5 Mhz
with the system
with a non-pipelined ROM.
Holger