ST72324xx-Auto
I/O ports
Figure 28. I/O port general block diagram
Register
access
Alternate
output
1
0
Alternate
enable
DR
VDD
P-buffer
(see table 24 below)
Pull-up
(see table 24 below)
VDD
DDR
Pull-up
condition
Pad
OR
) OR SEL
If implemented
uct(s DDR SEL
Prod DR SEL
1
te 0
ole External
s interrupt
b source (eix)
N-buffer
CMOS
Schmitt
trigger
Diodes
(see table 24 below)
Analog
input
Alternate
input
) - O Table 28. I/O port mode options
duct(s Configuration mode
Pull-up P-buffer
Diodes
to VDD
to VSS
roFloating with/without Interrupt
Input
PPull-up with/without Interrupt
te Push-pull
leOutput Open drain (logic level)
so True open drain
Off
Off
On
On
On
On
Off
Off
NI
NI
NI(1)
Ob 1. The diode to VDD is not implemented in the true open drain pads. A local protection between the pad and
VSS is implemented to protect the device against positive stress.
Legend:
NI = not implemented
Off = implemented not activated
On = implemented and activated
Doc ID 13841 Rev 1
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