HD74AC182
Rev.2.00, Jul.16.2004, page 2 of 6
Logic Symbol
C
n
G
P
P
0
C
n+x
C
n+y
C
n+z
G
0
P
1
G
1
P
2
G
2
P
3
G
3
Pin Names
Cn Carry Input
G0, G2Carry Generate Inputs (Active Low)
G1Carry Generate Input (Active Low)
G3Carry Generate Input (Active Low)
P0, P1Carry Propagate Inputs (Active Low)
P2Carry Propagate Input (Active Low)
P3Carry Propagate Input (Active Low)
Cn + x to Cn + z Carry Outputs
GCarry Generate Output (Active Low)
PCarry Propagate Output (Active Low)
Logic Diagram
Cn
Cn+x Cn+y Cn+z
G0P0G1
GP
P1G2P2G3P3
Please note that this diagram is provided only for the un derstanding of logic operations and should not be
used to estimate propagation delays.
Functional Description
The HD74AC182/HD74ACT182 carry lookahead generator accepts up to four pairs of Active Low Carry Propagate (P0
to P3) and Carry Generate (G0 to G3) signals and an Active High Carry input (Cn) and provides anticipated Active High
carries (Cn + x, Cn + y , Cn + z) across four groups of binary adders. The HD74AC182/HD74ACT182 also has Active Low
Carry Propagate (P) and Carry Generate (G) outputs which may be used for further level of lookahead. The logic
equations provided at the outputs are: