5 Nov
2001
5 Nov
'01
10:13 a.m.
ajp166 wrote:
Tony,
Faster as in is sub 150ns are fairly common and cheap. Whats
problemtic is that the ALU must do about 8-16 different operations
so that would be at least a 512kN part or larger.
Also 74(ALS,F,AS)381 in the 16 bit or wider range would be hard
pressed to do better than 50ns even with carry lookahead.
Having a F-data sheet here lets check that 32 bit alu.
Sel to ~PG 15 ns 74F381
~PG to ~PG 12 ns 74F182
~PG to CY 9 ns 74F182
cy to F 13 ns 74F382
-----------------------
49 ns
Yep close. Ben Franchuk.
--
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"Pre-historic Cpu's" http://www.jetnet.ab.ca/users/bfranchuk