MM54HC181 MM74HC181 Arithmetic Logic Units Function Generators
January 1988
MM54HC181 MM74HC181
Arithmetic Logic Units Function Generators
General Description
These arithmetic logic units (ALU) function generators uti-
lize advanced silicon-gate CMOS technology They possess
the high noise immunity and low power consumption of
standard CMOS integrated circuits as well as the ability to
drive 10 LS-TTL loads
The MM54HC181 MM74HC181 are arithmetic logic unit
(ALU) function generators that have a complexity of 75
equivalent gates on a monolithic chip These circuits per-
form 16 binary arithmetic operations on two 4-bit words as
shown in Tables 1 and 2 These operations are selected by
the four function-select lines (S0 S1 S2 S3) and include
addition subtraction decrement and straight transfer
When performing arithmetic manipulations the internal car-
ries must be enabled by applying a low-level voltage to the
mode control input (M) A full carry look-ahead scheme is
made available in these devices for fast simultaneous carry
generation by means of two cascade-outputs (pins 15 and
17) for the four bits in the package When used in conjunc-
tion with the MM54HC182 or MM74HC182 full carry look-
ahead circuits high-speed arithmetic operations can be per-
formed The method of cascading HC182 circuits with these
ALU鈥檚 to provide multi-level full carry look-ahead is illustrat-
ed under typical applications data for the MM54HC182
MM74HC182
If high speed is not of importance a ripple-carry input (C
n
)
and a ripple-carry output (C
n
a
4) are available However
the ripple-carry delay has also been minimized so that arith-
metic manipulations for small word lengths can be per-
formed without external circuitry
Features
Y
Y
Y
Y
Y
Y
Full look-ahead for high-speed operations on
long words
Arithmetic operating modes
Addition
Subtraction
Shift operand a one position magnitude comparison
Plus twelve other arithmetic operations
Logic function modes
Exclusive-OR
Comparator
AND NAND OR NOR
Plus ten other logic operations
Wide operating voltage range 2V 鈥?6V
Low input current 1
mA
maximum
Low quiescent current 80
mA
maximum
Connection Diagram
Dual-In-Line Package
Pin Designations
Designation
A3 A2 A1 A0
B3 B2 B1 B0
S3 S2 S1 S0
C
n
M
F3 F2 F1 F0
A
e
B
P
C
n
a
4
G
TL F 5320 鈥?1
Pin Nos
19 21 23 2
18 20 22 1
3 4 5 6
7
8
13 11 10 9
14
15
16
17
24
12
Function
Word A Inputs
Word B Inputs
Function-Select
Inputs
Inv Carry Input
Mode Control
Input
Function Outputs
Comparator Outputs
Carry Propagate
Output
Inv Carry Output
Carry Generate
Output
Supply Voltage
Ground
V
CC
GND
Top View
Order Number MM54HC181 or MM74HC181
C
1995 National Semiconductor Corporation
TL F 5320
RRD-B30M105 Printed in U S A
1
2
3
4
5
6
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8
9
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