12 Apr
2002
12 Apr
'02
9:39 a.m.
Richard Erlacher wrote:
Using a PROM to implement a combinatorial path has
always been the most costly
way to do it. I don't think it was as common as you suggest. Such an
application is likely to lead to very sparse ROM utilization. The ROM has a
fixed Or and fixed AND array, hence has to have many more registers in it than
a programmable logic device capable of the same logic, and, likewise, many
more than the equivalent logic implemented discretely in SSI/MSI logic.
How ever the ROM does contain ALL the possible states compared to PAL's
or discrete logic.
BTW B.G micro does sell 74LS170's, and AM2901's.
--
Ben Franchuk - Dawn * 12/24 bit cpu *
www.jetnet.ab.ca/users/bfranchuk/index.html