INTEGRATED CIRCUITS
DATA SHEET
For a complete data sheet, please also download:
•
The IC06 74HC/HCT/HCU/HCMOS Logic Family Specifications
•
The IC06 74HC/HCT/HCU/HCMOS Logic Package Information
•
The IC06 74HC/HCT/HCU/HCMOS Logic Package Outlines
74HC/HCT182
Look-ahead carry generator
Product specification
File under Integrated Circuits, IC06
December 1990
Philips Semiconductors
Product specification
Look-ahead carry generator
FEATURES
•
Provides carry look-ahead across a group of four ALU’s
•
Multi-level look-ahead for high-speed arithmetic
operation over long word length
•
Output capability: standard
•
I
CC
category: MSI
GENERAL DESCRIPTION
The 74HC/HCT182 are high-speed Si-gate CMOS devices
and are pin compatible with low power Schottky TTL
(LSTTL). They are specified in compliance with JEDEC
standard no. 7A.
The 74HC/HCT182 carry look-ahead generators accept
up to four pairs of active LOW carry propagate (P
0
, P
1
, P
2
,
P
3
) and carry generate (G
0
, G
1
, G
2
, G
3
) signals and an
active HIGH carry input (C
n
). The devices provide
QUICK REFERENCE DATA
GND = 0 V; T
amb
= 25
°C;
t
r
= t
f
= 6 ns
74HC/HCT182
anticipated active HIGH carries (C
n+x
, C
n+y
, C
n+z
) across
four groups of binary adders.
The “182” also has active LOW carry propagate (P) and
carry generate (G) outputs which may be used for further
levels of look-ahead.
The logic equations provided at the outputs are:
C
n+x
= G
0
+ P
0
C
n
C
n+y
= G
1
+ P
1
G
0
+ P
1
P
0
C
n
C
n+z
= G
2
+ P
2
G
1
+ P
2
P
1
G
0
+ P
2
P
1
P
0
C
n
G
=
G
3
+
P
3
G
2
+
P
3
P
2
G
1
+
P
3
P
2
P
1
G
O
P
=
P
3
P
2
P
1
P
0
The “182” can also be used with binary ALU’s in an active
LOW or active HIGH input operand mode. The
connections to and from the ALU to the carry look-ahead
generator are identical in both cases.
TYPICAL
SYMBOL
t
PHL
/ t
PLH
PARAMETER
propagation delay
P
n
to P
C
n
to any output
P
n
or G
n
to any output
input capacitance
power dissipation capacitance per
package
notes 1 and 2
CONDITIONS
HC
C
L
= 15 pF; V
CC
= 5 V
11
17
14
3.5
50
14
21
17
3.5
50
ns
ns
ns
pF
pF
HCT
UNIT
C
I
C
PD
Notes
1. C
PD
is used to determine the dynamic power dissipation (P
D
in
µW):
P
D
= C
PD
×
V
CC2
×
f
i
+ ∑
(C
L
×
V
CC2
×
f
o
) where:
f
i
= input frequency in MHz
f
o
= output frequency in MHz
∑
(C
L
×
V
CC2
×
f
o
) = sum of outputs
C
L
= output load capacitance in pF
V
CC
= supply voltage in V
2. For HC the condition is V
I
= GND to V
CC
For HCT the condition is V
I
= GND to V
CC
−
1.5 V
ORDERING INFORMATION
See
“74HC/HCT/HCU/HCMOS Logic Package Information”.
December 1990
2
Philips Semiconductors
Product specification
Look-ahead carry generator
PIN DESCRIPTION
PIN NO.
3, 1, 14, 5
4, 2, 15, 6
7
8
9
10
11
12
13
16
SYMBOL
G
0
to G
3
P
0
to P
3
P
GND
C
n+z
G
C
n+y
C
n+x
C
n
V
CC
NAME AND FUNCTION
carry generate inputs (active LOW)
carry propagate inputs (active LOW)
carry propagate output (active LOW)
ground (0 V)
function output
carry generate output (active LOW)
function output
function output
carry input (active HIGH)
positive supply voltage
74HC/HCT182
Fig.1 Pin configuration.
Fig.2 Logic symbol.
Fig.3 IEC logic symbol.
December 1990
3
下载中心专版
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
