ST STM32WL55JC Reference Manual page 394

General-purpose I/Os (GPIO)
To on-chip
peripheral
Alternate function input
Read
Write
Read/write
From on-chip
Alternate function output
peripheral
1) VDD_FT is specific to 5V-tolerant I/Os and different from VDD.
MODE(i)[1:0] OTYPER(i)
01
10
394/1454
Figure 44. Basic structure of a 5V-tolerant I/O port bit
TTL Schmitt
trigger
Input driver
Output driver
Table 70. Port bit configurations
OSPEED(i)[1:0]
0
0
0
0
1
1
1
1
SPEED[1:0]
0
0
0
0
1
1
1
1
on/off
V
DDIOx
P-MOS
Output
control
N-MOS
V
SS
Push-pull,
open-drain or
disabled
PUPD(i)[1:0]
00
01
10
11
00
01
10
11
00
01
10
11
00
01
10
11
RM0453 Rev 2
(1)
V
V
DD_FT
DDIOx
Protection
on/off
diode
Pull
up
I/O pin
on/off
Protection
Pull
down
diode
V
SS
V
SS
ai15939e
(1)
I/O configuration
GP output PP
GP output PP + PU
GP output PP + PD
Reserved
GP output OD
GP output OD + PU
GP output OD + PD
Reserved (GP output OD)
AF PP
AF PP + PU
AF PP + PD
Reserved
AF OD
AF OD + PU
AF OD + PD
Reserved
RM0453