7485: Difference between revisions
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This IC has been proposed as the PRG ROM decoder for [[NROM-368]]. | This IC has been proposed as the PRG ROM decoder for [[NROM-368]]. | ||
[[Category:7400 series]] | [[Category:7400 series|085]] | ||
Revision as of 06:22, 24 December 2012
The 7485 (74LS85, 74HC85) is a digital magnitude comparator IC.
,--\/--.
B3 --+ +-- Vcc
IA<B --+ +-- A3
IA=B --+ +-- B2
IA>B --+ 85 +-- A2
QA>B --+ +-- A1
QA=B --+ +-- B1
QA<B --+ +-- A0
GND --+ +-- B0
`------'
- A3-A0: 4-bit number A
- B3-B0: 4-bit number B
- IA<B: Cascade from next lower nibble (use false for lowest)
- IA=B: Cascade from next lower nibble (use true for lowest)
- IA>B: Cascade from next lower nibble (use false for lowest)
- QA<B: True if A < B, false if A > B
- QA=B: False if A < B or A > B
- QA>B: False if A < B, true if A > B
If A = B, then Q = I.
This IC has been proposed as the PRG ROM decoder for NROM-368.
