74lvt646 NXP Semiconductors, 74lvt646 Datasheet - Page 4

• Manufacturer Part Number: 74lvt646
• Description: 3.3v Octal Bus Transceiver/register 3-state
• Manufacturer: NXP Semiconductors

Philips Semiconductors
FUNCTION TABLE
H = High voltage level
L = Low voltage level
X = Don’t care
*
1998 Feb 19
3.3V Octal bus transceiver/register (3-State)
= Low-to-High clock transition
OE
REAL TIME BUS TRANSFER
H
H
X
X
L
L
L
L
OE
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.
A
BUS B TO BUS A
DIR CPAB CPBA SAB SBA
L
DIR
X
X
X
X
X
H
H
L
L
X
CPAB
X
H or L
H or L
INPUTS
X
X
X
X
B
L
CPBA
H or L
H or L
REAL TIME BUS TRANSFER
OE
X
X
X
X
L
A
BUS A TO BUS B
DIR CPAB CPBA SAB SBA
H
SAB
X
X
X
X
X
X
H
L
X
X
SBA
X
X
X
X
H
X
X
L
L
B
Unspecified
X
output*
Output
Input
Input
Input
An
4
DATA I/O
OE
L
L
H
A
A, B, OR A AND B
STORAGE FROM
DIR CPAB CPBA SAB SBA
H
L
X
Unspecified
output*
Output
Input
Input
Input
Bn
X
X
X
X
X
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
B
X
X
X
OPERATING MODE
OPERATING MODE
TRANSFER STORED DATA
OE
L
L
A
DIR CPAB CPBA SAB SBA
H
L
TO A OR B
H or L
X
74LVT646
Product specification
H or L
X
X
H
SV00049
B
H
X