ST72E311 ST72T311
I/O PORTS (Cont’d)
Table 11. Port Configuration
Port
Pin name
PA0:PA2 1)
Input (DDR = 0)
OR = 0
OR = 1
floating*
pull-up with interrupt
Output (DDR = 1)
OR = 0
OR =1
open-drain
push-pull
Port A
PA3
floating*
pull-up with interrupt open-drain
push-pull
PA4:PA7
floating*
true open drain, high sink capability
Port B
PB0:PB4
PB5:PB7 1)
floating*
floating*
pull-up with interrupt
pull-up with interrupt
open-drain
open-drain
push-pull
push-pull
Port C
PC0:PC7
floating*
pull-up
open-drain
push-pull
Port D
PD0:PD5
PD6:PD7 1)
floating*
floating*
pull-up
pull-up
open-drain
open-drain
push-pull
push-pull
Port E
Port F
PE0:PE1
PE4:PE7 1)
PF0:PF2
PF4, PF6, PF7
floating*
pull-up
floating*2)
floating*
floating*
pull-up with interrupt
pull-up
open-drain
push-pull
true open drain,
high sink capability3)
open-drain
push-pull
open-drain
push-pull
Notes:
1. ST72T311N only
2. For OTP/EPROM version, when OR=0: floating & when OR=1: reserved
3. For OTP/EPROM version, when OR=0: open-drain, high sink capability & when OR=1: reserved
* Reset state (The bits corresponding to unavailable pins are forced to 1 by hardware, this affects the reset status value).
Warning: All bits of the DDR register which correspond to unconnected I/Os must be left at their reset val-
ue. They must not be modified by the user otherwise a spurious interrupt may be generated.
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