74F647 Datasheet, PDF (4/12 Pages) NXP Semiconductors – Octal transceiver/register, non-inverting open-collector

Philips Semiconductors
Octal transceivers/registers (open-collector)
Product specification
74F647/74F649
INPUT AND OUTPUT LOADING AND FAN-OUT TABLE
PINS
DESCRIPTION
74F(U.L.)
HIGH/LOW
LOAD VALUE
HIGH/LOW
A0 - A7
B0 - B7
CPAB
CPBA
SAB
SBA
DIR
OE
A inputs
B inputs
A-to-B clock input
B-to-A clock input
A-to-B select input
B-to-A select input
Data flow Directional control enable input
Output Enable input
1.0/0.033
1.0/0.033
1.0/0.033
1.0/0.033
1.0/0.033
1.0/0.033
1.0/0.066
1.0/0.066
20µA/20µA
20µA/20µA
20µA/20µA
20µA/20µA
20µA/20µA
20µA/20µA
20µA/20µA
20µA/20µA
A0 - A7
A outputs
OC/106.7
OC/64mA
B0 - B7
B outputs
OC/106.7
OC/64mA
NOTE: One (1.0) FAST Unit Load is defined as: 20µA in the High state and 0.6mA in the Low state. OC = Open Collector
FUNCTION TABLE
INPUTS
OE
DIR CPAB CPBA SAB SBA
DATA I/O
A0-A7
B0-B7
OPERATING MODE
X
X
↑
X
X
X
Input
Unspecified* Store A, B unspecified* Store A, B unspecified*
X
X
X
↑
X
X Unspecified*
Input
Store B, A unspecified* Store B, A unspecified*
H
X
↑
↑
X
X
H
X H or L H or L X
X
Input
Input
Store A and B data
Isolation, hold storage
Store A and B data
Isolation, hold storage
L
L
L
L
X
X
X
X H or L X
L
H
Output
Input
Real time B data to A bus Real time B data to A bus
Stored B data to A bus Stored B data to A bus
L
H H or L X
L
X
L
H
X
X
H
X
Input
Output
Real time A data to B bus Real time A data to B bus
Stored A data to B bus Stored A data to B bus
H = High voltage level
L = Low voltage level
X = Don’t care
↑ = Low-to-High clock transition
* = The data output function may be enabled or disabled by various signals at the OE and DIR inputs. 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.
LOGIC DIAGRAM – 74F647
OE ²¹
DIR
CPBA
3
23
SBA ²²
CPAB ¹
SAB ²
LOGIC DIAGRAM – 74F649
OE ²¹
DIR
CPBA
3
23
SBA ²²
CPAB ¹
SAB ²
1 of 8 Channels
4
A0
1D
C1
1D
C1
20
B0
1 of 8 Channels
4
A0
1D
C1
1D
C1
20
B0
1992 Feb 28
To 7 other channels
SF01202
4
To 7 other channels
SF01203