
3
4109LS–8051–02/08
AT8xC51SND1C
4.
Pin Description
4.1
Pinouts
Figure 4-1.
AT8xC51SND1C 80-pin QFP Package
Notes:
1. ISP pin is only available in AT89C51SND1C product.
Do not connect this pin on AT83SND1C product.
2. PSEN pin is only available in AT80C51SND1C product.
AT89C51SND1C-RO (FLASH)
AT83SND1C-RO (ROM)
AT80C51SND1C-RO (ROMLESS)
P
0
.3
/A
D
3
P
0
.4
/A
D
4
P
0
.5
/A
D
5
V
S
V
D
P
0
.6
/A
D
6
P
0
.7
/A
D
7
P
2
.0
/A
8
P
2
.1
/A
9
P
3
.1
/T
X
D
P
3
.2
/I
N
T
0
P
3
.3
/I
N
T
1
P
3
.4
/T
0
P
3
.0
/R
X
D
1
2
3
4
5
6
7
8
13
11
10
P2.2/A10
P2.3/A11
P2.4/A12
P2.6/A14
P2.5/A13
P2.7/A15
MCLK
MDAT
MCMD
P
0
.2
/A
D
2
P
0
.1
/A
D
1
P
0
.0
/A
D
0
PVSS
VSS
X2
X1
TST
V
S
9
12
14
15
16
P
4
.3
/S
S
P
4
.2
/S
C
K
P
4
.1
/M
O
S
I
P
4
.0
/M
IS
O
VSS
VDD
RST
SCLK
DSEL
DCLK
DOUT
A
IN
1
A
IN
0
A
R
E
F
N
A
R
E
F
P
A
V
S
A
V
D
P
3
.7
/R
D
P
3
.6
/W
R
P
3
.5
/T
1
V
D
P1.0/KIN0
P1.1/KIN1
P1.2/KIN2
P1.3/KIN3
P1.4
P1.5
P1.7/SDA
FILT
PVDD
VDD
P1.6/SCL
17
18
19
20
2
1
2
3
2
4
2
5
2
6
2
7
2
8
3
1
3
0
2
9
3
2
3
4
3
5
3
6
3
7
3
8
3
9
4
0
41
42
43
44
45
46
47
48
53
51
50
49
52
54
55
56
57
58
59
60
6
1
6
2
6
3
6
4
6
5
6
7
6
8
7
3
7
1
7
0
6
9
7
2
7
4
7
5
7
6
7
8
7
9
8
0
ALE
ISP1/PSEN2/NC
UVDD
UVSS
P
5
.0
P
5
.1
P
4
.7
P
4
.6
D
-
D
+
P
5
.3
P
5
.2
VSS
VDD
P4.5
P4.4