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VRS51x550/560
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Pin Descriptions for PLCC-44
TABLE 2: PIN DESCRIPTIONS FOR PLCC-44
PLCC
- 44
Name
I/O
Function
1
NC
-
No Connect
T2
I
Timer 2 Clock Out
2
P1.0
I/O
Bit 0 of Port 1
T2EX
I
Timer 2 Control
3
P1.1
I/O
Bit 1 of Port 1
4
P1.2
I/O
Bit 2 of Port 1
5
P1.3
I/O
Bit 3 of Port 1
6
P1.4
I/O
Bit 4 of Port 1
7
P1.5
I/O
Bit 5 of Port 1
8
P1.6
I/O
Bit 6 of Port 1
9
P1.7
I/O
Bit 7 of Port 1
10
RES
I
Reset
RXD
I
Receive Data
11
P3.0
I/O
Bit 0 of Port 3
12
NC
-
No Connect
TXD
O
Transmit Data &
13
P3.1
I/O
Bit 1 of Port 3
#INT0
I
External Interrupt 0
14
P3.2
I/O
Bit 2 of Port 3
#INT1
I
External Interrupt 1
15
P3.3
I/O
Bit 3 of Port 3
T0
I
Timer 0
16
P3.4
I/O
Bit 4 of Port 3
T1
I
Timer 1 & 3
17
P3.5
I/O
Bit 5 of Port
#WR
O
Ext. Memory Write
18
P3.6
I/O
Bit 6 of Port 3
#RD
O
Ext. Memory Read
19
P3.7
I/O
Bit 7 of Port 3
20
XTAL2
O
Oscillator/Crystal Output
21
XTAL1
I
Oscillator/Crystal In
22
VSS
-
Ground
23
NC
-
No Connect
P1.6
P1.5
RESET
P1.7
NC
RXD/P3.0
#INT0/P3.2
TXD/P3.1
T0/P3.4
#INT1/P3.3
T1/P3.5
P2.6/A14
P2.5/A13
#PSEN
P2.7/A15
NC
ALE
P0.7/AD7
#EA
P0.5/AD5
P0.6/AD6
P0.4/AD4
1
VRS51x550/560
PLCC-44
6
7
17
18
28
29
39
40
5
4
3
2
44 43 42 41
23
19 20 21 22
27
24 25 26
8
9
10
11
12
13
14
15
16
38
37
36
35
34
33
32
31
30
PLCC
- 44
Name
I/O
Function
P2.0
I/O
Bit 0 of Port 2
24
A8
O
Bit 8 of External Memory Address
P2.1
I/O
Bit 1 of Port 2
25
A9
O
Bit 9 of External Memory Address
P2.2
I/O
Bit 2 of Port 2
26
A10
O
Bit 10 of External Memory Address
P2.3
I/O
Bit 3 of Port 2 &
27
A11
O
Bit 11 of External Memory Address
P2.4
I/O
Bit 4 of Port 2
28
A12
O
Bit 12 of External Memory Address
P2.5
I/O
Bit 5 of Port 2
29
A13
O
Bit 13 of External Memory Address
P2.6
I/O
Bit 6 of Port 2
30
A14
O
Bit 14 of External Memory Address
P2.7
I/O
Bit 7 of Port 2
31
A15
O
Bit 15 of External Memory Address
32
#PSEN
O
Program Store Enable
33
ALE
O
Address Latch Enable
34
NC
-
No Connect
35
#EA
I
External Access
P0.7
I/O
Bit 7 Of Port 0
36
AD7
I/O
Data/Address Bit 7 of External
Memory
P0.6
I/O
Bit 6 of Port 0
37
AD6
I/O
Data/Address Bit 6 of External
Memory
P0.5
I/O
Bit 5 of Port 0
38
AD5
I/O
Data/Address Bit 5 of External
Memory
P0.4
I/O
Bit 4 of Port 0
39
AD4
I/O
Data/Address Bit 4 of External
Memory
P0.3
I/O
Bit 3 Of Port 0
40
AD3
I/O
Data/Address Bit 3 of External
Memory
P0.2
I/O
Bit 2 of Port 0
41
AD2
I/O
Data/Address Bit 2 of External
Memory
P0. 1
I/O
Bit 1 of Port 0 & Data
42
AD1
I/O
Address Bit 1 of External Memory
P0.0
I/O
Bit 0 Of Port 0 & Data
43
AD0
I/O
Address Bit 0 of External Memory
44
VDD
-
VCC
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