RM0440 Rev 4 351/2126
RM0440 General-purpose I/Os (GPIO)
368
Figure 25 and Figure 26 show the basic structures of a standard and a 5-Volt tolerant I/O
port bit, respectively. Table 56 gives the possible port bit configurations.
Figure 25. Basic structure of an I/O port bit
Figure 26. Basic structure of a 5-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
Input data register
Output data register
Read/write
From on-chip
peripheral
To on-chip
peripheral
Output
control
Analog
on/off
Pull
Pull
down
on/off
I/O pin
V
DDIOx
V
DDIOx
V
SS
V
SS
trigger
V
SS
V
DDIOx
Protection
diode
Protection
diode
on/off
Input driver
Output driver
up
P-MOS
N-MOS
Read
Bit set/reset registers
Write
Analog
MS31476V1
Alternate function output
Alternate function input
Push-pull,
open-drain or
disabled
Output data register
Read/write
From on-chip
peripheral
To on-chip
peripheral
Output
control
on/off
Pull
Pull
on/off
I/O pin
V
DDIOx
V
DDIOx
V
SS
V
SS
TTL Schmitt
trigger
V
SS
V
DD_FT
(1)
Protection
diode
Protection
diode
on/off
Input driver
Output driver
down
up
P-MOS
N-MOS
Read
Bit set/reset registers
Write
Input data register
ai15939d