
7-1400
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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CD40181BMS
CMOS 4 Bit Arithmetic Logic Unit
Description
The CD40181BMS is a low power four bit parallel arithmetic
logic unit (ALU) capable of providing 16 binary arithmetic
operations on two four-bit words and 16 logical functions of
two Boolean variables. The mode control input M selects
logical (M = High) or arithmetic (M = Low) operation. The
four select inputs (S0, S1, S2, and S3) select the desired
logical or arithmetic functions, which include AND, OR,
NAND, NOR and exclusive-OR and-NOR in the logic mode,
and addition, subtraction, decrement, left-shift and straight
transfer in the arithmetic mode, according to the truth table.
The CD40181BMS operation may be interpreted with either
active-low or active-high data at the A and B word inputs and
the function outputs F, by using the appropriate truth table.
The CD40181BMS contains logic for full look ahead carry
operation for fast carry generation using the carry-generate
and carry-propagate outputs G and P for the four bits of the
CD40181BMS. Use of the CD40182BMS look-ahead carry
generator in conjunction with multiple CD40181BMS’s
permits high speed arithmetic operations on long words. A
ripple carry output Cn+4 is available for use in systems
where speed is not of primary importance.
Also included in the CD40181BMS is a comparator output
A = B, which assumes a high level whenever the two four-bit
input words A and B are equal and the device is in the
subtract mode. In addition, relative magnitude information
may be derived from the carry-in input Cn and ripple carry-
out output Cn+4 by placing the unit in the subtract mode and
externally decoding using the information in Table B.
The CD40181BMS is similar to industry types MC14581 and
74181.
The CD40181BMS is supplied in these 24-lead outline
packages:
Braze Seal DIP
Ceramic Flatpack
HNZ
H4P
Features
High Voltage Type (20V Rating)
Full Look Ahead Carry for Speed Operations on Long
Words
Generates 16 Logic Functions of Two Boolean Variables
Generates 16 Arithmetic Functions of Two 4 Bit Binary
Words
A = B comparator Output Available
Ripple Carry Input and Output Available
Typical Addition Time 200ns at VDD = 10V
100% Tested for Quiescent Current at 20V
5V, 10V and 15V Parametric Ratings
Maximum Input Current of 1
μ
A at 18V Over Full Pack-
age Temperature Range; 100nA at 18V and +25
o
C
Noise Margin (Over Full Package/Temperature Range)
- 1V at VDD = 5V
- 2V at VDD = 10V
- 2.5V at VDD = 15V
Standardized Symmetrical Output Characteristics
Meets All Requirements of JEDEC Tentative Standard
No. 13B, “Standard Specifications for Description of
‘B’ Series CMOS Devices”
Applications
Parallel Arithmetic Units
Process Controllers
Low Power Minicomputers
Pinout
CD40181BMS ACTIVE-LOW DATA
TOP VIEW
1
2
3
4
5
6
7
8
9
10
11
12
B0
A0
S3
S2
S1
S0
Cn
M
F0
F1
F2
VSS
16
17
18
19
20
21
22
23
24
15
14
13
VDD
B1
A2
B2
A3
G
P
A = B
F3
A1
B3
Cn+4
December 1992
File Number
3361