Pin Description
Pin Definition
Pin Name
DIP-40
Pin Number
PLCC-44
PQFP-44
Type
Description
P0.0 (AD0)
P0.1 (AD1)
P0.2 (AD2)
P0.3 (AD3)
P0.4 (AD4)
P0.5 (AD5)
P0.6 (AD6)
P0.7 (AD7)
P1.0 (T2)
P1.1 (T2EX)
P1.2
P1.3
P1.4
P1.5
P1.6
P1.7
39
38
37
36
35
34
33
32
1
2
3
4
5
6
7
8
43
42
41
40
39
38
37
36
2
3
4
5
6
7
8
9
37
36
35
34
33
32
31
30
40
41
42
43
44
1
2
3
B
Port0 is an open-drain, bi-directional IO
port. When
1s
are written to Port0, they
become high-impedance inputs. Port0 is
also multiplexed with low-order address
or data bus during accesses to external
program and data memory.
BU General-purposed I/O with weak pull-up
resistance inside. When
1s
are written
into Port1, the strong output driving
PMOS only turn-on two clock periods
and then the weak pull-up resistance
keep the port high.
P1.0 is also used as one of event
sources for timer2, or output carrier of
timer2, alias T2.
P1.1 is also used as one of
interrupt-controlling sources for time2,
alias T2EX.
P2.0 (A8)
P2.1 (A9)
P2.2 (A10)
P2.3 (A11)
P2.4 (A12)
P2.5 (A13)
P2.6 (A14)
P2.7 (A15)
P3.0 (RXD)
P3.1 (TXD)
P3.2 (INT0)
P3.3 (INT1)
P3.4 (T0)
4
21
22
23
24
25
26
27
28
10
11
12
13
14
24
25
26
27
28
29
30
31
11
13
14
15
16
18
19
20
21
22
23
24
25
5
7
8
9
10
BU Port2 is an 8-bits bi-directional I/O port
with pull-up resistance. Except being as
GPIO, Port2 emits the high-order
address bytes during accessing to
external program and data memory.
BU General-purposed I/O with weak pull-up
resistance inside. When
1s
are written
into Port1, the strong output driving
PMOS only turn-on two clock periods
and then the weak pull-up resistance
MPC89x51A Data Sheet
MEGAWIN
MEGAWIN [ MEGAWIN TECHNOLOGY CO., LTD ]
