SM5953
8-Bit Micro-controller
15KB with ISP Flash
& 256B RAM embedded
5. GPIO
Port 0 ~ Port 3 are the general purpose IO of this controller. Most of the ports are multiplexed with the other
outputs, e.g., Port 3[0] is also used as RXD in the UART application. Port0 is open-drain in the input and output
high condition, so external pull-up resistors are required. As for the other ports, the pull-up resistors are built
internally.
For general purpose applications, every pin can be assigned to either high or low independently
because their SFRs are bit addressable as given below：
Mnemonic: P0
Address: 80h
7
P0.7
6
P0.6
5
P0.5
4
P0.4
3
P0.3
2
P0.2
1
P0.1
0
P0.0
Reset
FFh
P0.7~ 0: Port0 [7] ~ Port0[0]
Mnemonic: P1
Address: 90h
7
P1.7
6
P1.6
5
P1.5
4
P1.4
3
P1.3
2
P1.2
1
P1.1
0
P1.0
Reset
FFh
P1.7~ 0: Port1 [7] ~ Port1 [0]
Mnemonic: P2
Address: A0h
7
P2.7
6
P2.6
5
P2.5
4
P2.4
3
P2.3
2
P2.2
1
P2.1
0
P2.0
Reset
FFh
P2.7~ 0: Port2 [7] ~ Port2 [0]
Mnemonic: P3
Address: B0h
7
6
5
4
3
2
1
0
Reset
P3.7
P3.6
P3.5
P3.4
P3.3
P3.2
P3.1
P3.0
FFh
P3.7~ 0: Port3 [7] ~ Port3 [0]
Specifications subject to change without notice contact your sales representatives for the most recent information.
ISSFD-M074 Ver B SM5953 12/27/2013
- 19 -
SYNCMOS [ SYNCMOS TECHNOLOGIES,INC ]
