74F779 Datasheet, PDF (2/7 Pages) NXP Semiconductors – 8-bit bidirectional binary counter 3-State

Unit Loading/Fan Out
Pin Names
I/O₀–I/O₇
S₀, S₁
OE
CET
CP
TC
Description
Data Inputs
Data Outputs
Select Inputs
Output Enable Input (Active LOW)
Count Enable Trickle Input (Active LOW)
Clock Pulse Input (Active Rising Edge)
Terminal Count Output (Active LOW)
U.L.
HIGH/LOW
0.25/0.33
75/15 (12.5)
0.25/0.33
0.25/0.33
0.25/0.33
0.25/0.33
25/12.5
Input I_IH/I_IL
Output I_OH/I_OL
5 µA/−0.2 mA
−3 mA/24 mA (20 mA)
5 µA/−0.2 mA
5 µA/−0.2 mA
5 µA/−0.2 mA
5 µA/−0.2 mA
−1 mA/20 mA
Function Table
S₁
S₀
CET
OE
CP
X
X
X
H
X
X
X
L
L
(Not LL)
H
L
L
H
X
X
H
L
L
L
H
X
X
X
^X

H = HIGH Voltage Level
L = LOW Voltage Level
X = Immaterial
= LOW-to-HIGH Clock Transition
(Not LL) means S₀ and S₁ should never both be LOW level at the same time.
Function
I/O₀ to I/O₇ in High Z
Flip-Flop Outputs Appear on I/O Lines
Parallel Load All Flip-Flops
Hold (TC Held HIGH)
Count Up
Count Down
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