MC74AC648N Motorola, MC74AC648N Datasheet - Page 2

• Manufacturer Part Number: MC74AC648N
• Description: OCTAL TRANSCEIVER/REGISTER WITH 3-STATE OUTPUTS (INVERTING)
• Manufacturer: Motorola

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FUNCTION TABLE
* The data output functions may be enabled or disabled by various signals at the G and DIR inputs. Data input functions are always enabled; i.e., data at the bus
H = HIGH Voltage Level
L = LOW Voltage Level
X = Immaterial
GND
CAB
PIN NAMES
A 0 –A 7
B 0 –B 7
CAB, CBA
SAB, SBA
DIR, G
SAB
pins will be stored on every LOW-to-HIGH transition of the appropriate clock inputs.
DIR
= LOW-to-HIGH Transition
A 0
A 1
A 2
A 3
A 4
A 5
A 6
A 7
G
H
H
L
L
L
L
10
11
12
1
2
3
4
5
6
7
8
9
DIR
X
X
H
H
L
L
Data Register Inputs
Data Register A Outputs
Data Register B Inputs
Data Register B Outputs
Clock Pulse Inputs
Transmit/Receive Inputs
Output Enable Inputs
H or L
H or L
CAB
X
X
X
Inputs
24
23
22
21
20
19
18
17
16
15
14
13
H or L
CBA
X
X
X
X
V CC
CBA
SBA
G
B 0
B 1
B 2
B 3
B 4
B 5
B 6
B 7
SAB
X
X
X
X
H
L
MC74AC648 MC74ACT648
CBA
CAB
SBA
SAB
DIR
A 0
G
SBA
H
X
X
L
X
X
Please note that this diagram is provided only for the understanding of logic
operations and should not be used to estimate propagation delays.
FACT DATA
A 0 –A 7
Output
Input
Input
5-2
1 OF 8 CHANNELS
Data I/O*
D 0
C 0
B 0 –B 7
Output
Input
Input
TO 7 OTHER CHANNELS
LOGIC DIAGRAM
Isolation
Store A and B Data
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
Operation or Function
Operation or Function
D 0
C 0
B 0