
RM0008
General-purpose and alternate-function I/Os (GPIOs and AFIOs)
Doc ID 13902 Rev 12
155/1096
Figure 13.
Basic structure of a standard I/O port bit
Figure 14.
Basic structure of a five-volt tolerant I/O port bit
1.
V
DD_FT
is a potential specific to five-volt tolerant I/Os and different from V
DD
.
Alternate Function Output
Alternate Function Input
Push-pull,
open-drain or
disabled
Inpu
t dat
a regi
st
er
Ou
tpu
t dat
a reg
ist
e
r
Read/write
From on-chip
peripheral
To on-chip
peripheral
Output
control
Analog Input
on/off
on/off
I/O pin
V
DD
V
DD
V
SS
V
SS
TTL Schmitt
trigger
V
SS
V
DD
Protection
diode
Protection
diode
on/off
Input driver
Output driver
P-MOS
N-MOS
Read
B
it s
e
t/
re
se
t reg
ist
e
rs
Write
ai14781
Alternate Function Output
Alternate Function Input
Push-pull,
open-drain or
disabled
Inpu
t dat
a regi
st
er
Ou
tpu
t dat
a reg
ist
e
r
Read/write
From on-chip
peripheral
To on-chip
peripheral
Output
control
Analog Input
on/off
on/off
I/O pin
V
DD
V
DD
V
SS
V
SS
TTL Schmitt
trigger
V
SS
V
DD_FT
(1)
Protection
diode
on/off
Input driver
Output driver
P-MOS
N-MOS
Read
B
it s
e
t/
re
se
t reg
ist
e
rs
Write
ai14782