74ABT646A Philips Semiconductors, 74ABT646A Datasheet - Page 4

• Manufacturer Part Number: 74ABT646A
• Description: Octal bus transceiver/register 3-State
• Manufacturer: Philips Semiconductors

Philips Semiconductors
FUNCTION TABLE
H = High voltage level
L = Low voltage level
X = Don’t care
*
LOGIC DIAGRAM
1998 Feb 17
Octal bus transceiver/register (3-State)
= Low-to-High clock transition
OE
H
H
X
X
L
L
L
L
The data output function may be enabled or disabled by various signals at the OE input. Data input functions are always enabled, i.e.,
data at the bus pins will be stored on every Low-to-High transition of the clock.
DIR
X
X
X
X
H
H
L
L
CPBA
CPAB
SBA
SAB
A0
A1
A2
A3
A4
A5
A6
A7
DIR
OE
CPAB
H or L
H or L
INPUTS
10
11
X
X
X
X
4
5
6
7
8
9
21
23
22
3
1
2
CPBA
H or L
H or L
X
X
X
X
SAB
1of 8 Channels
X
X
X
X
X
X
H
L
1D
SBA
C1
X
X
X
X
H
X
X
L
Q
Unspecified
output*
DETAIL A X 7
Output
Input
Input
Input
An
4
DATA I/O
Unspecified
output*
Output
Input
Input
Input
Bn
Q
C1
1D
Store A, B unspecified
Store B, A unspecified
Store A and B data
Isolation, hold storage
Real time B data to A bus
Stored B data to A bus
Real time A data to B bus
Stored A data to B bus
OPERATING MODE
OPERATING MODE
20
19
18
17
16
15
14
13
SA00086
74ABT646A
B0
B1
B2
B3
B4
B5
B6
B7
Product specification