ST72321B Datasheet, PDF (50/187 Pages) STMicroelectronics – 64/44-pin 8-bit MCU with 32 to 60K Flash/ROM, ADC, five timers, SPI, SCI, I2C interface

I/O PORTS (Cont’d)
9.5.1 I/O Port Implementation
The I/O port register configurations are summa-
rised as follows.
Standard Ports
PA5:4, PC7:0, PD7:0, PE7:3,
PE1:0, PF7:3,
MODE
floating input
pull-up input
open drain output
push-pull output
DDR OR
0
0
0
1
1
0
1
1
Interrupt Ports
PA2:0, PB6:5, PB4, PB2:0, PF1:0 (with pull-up)
MODE
floating input
pull-up interrupt input
open drain output
push-pull output
DDR OR
0
0
0
1
1
0
1
1
MODE
floating input
floating interrupt input
open drain output
push-pull output
True Open Drain Ports
PA7:6
MODE
floating input
open drain (high sink ports)
Pull-Up Input Port PE2
MODE
pull-up input
open drain output*
push-pull output*
DDR OR
0
0
0
1
1
0
1
1
DDR
0
1
DDR OR
0
x
1
0
1
1
Table 12. Port Configuration
Port
Pin name
Port A
Port B
Port C
Port D
Port E
Port F
PA7:6
PA5:4
PA3
PA2:0
PB7, PB3
PB6:5, PB4,
PB2:0
PC7:0
PD7:0
PE7:3, PE1:0
PE2
PF7:3
PF2
PF1:0
*Pull-up always activated on PE2.
OR = 0
floating
floating
floating
floating
Input
OR = 1
floating
pull-up
floating interrupt
pull-up interrupt
floating interrupt
floating
pull-up interrupt
floating
pull-up
floating
pull-up
floating
pull-up
pull-up input only
floating
pull-up
floating
floating interrupt
floating
pull-up interrupt
Output
OR = 0
OR = 1
true open-drain
open drain
push-pull
open drain
push-pull
open drain
push-pull
open drain
push-pull
open drain
push-pull
open drain
open drain
open drain
open drain*
open drain
open drain
open drain
push-pull
push-pull
push-pull
push-pull*
push-pull
push-pull
push-pull
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