ST72F321 STMICROELECTRONICS [STMicroelectronics], ST72F321 Datasheet - Page 47

• Manufacturer Part Number: ST72F321
• Description: 64/44-PIN 8-BIT MCU WITH 32 TO 60K FLASH/ROM, ADC, FIVE TIMERS, SPI, SCI, I2C INTERFACE
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

I/O PORTS (Cont’d)
Figure 31. I/O Port General Block Diagram
Table 9. I/O Port Mode Options
Legend: NI - not implemented
Input
Output
REGISTER
ACCESS
SOURCE (ei
EXTERNAL
INTERRUPT
Off - implemented not activated
On - implemented and activated
DDR SEL
OR SEL
DR SEL
Floating with/without Interrupt
Pull-up with/without Interrupt
Push-pull
Open Drain (logic level)
True Open Drain
Configuration Mode
DDR
OR
x
DR
)
ALTERNATE
OUTPUT
ALTERNATE
ENABLE
If implemented
1
0
1
0
Pull-Up
Off
On
Off
NI
Note: The diode to V
true open drain pads. A local protection between
the pad and V
vice against positive stress.
N-BUFFER
PULL-UP
CONDITION
P-Buffer
Off
On
Off
NI
SS
SCHMITT
TRIGGER
CMOS
is implemented to protect the de-
V
DD
DD
NI (see note)
is not implemented in the
to V
On
DD
P-BUFFER
(see table below)
V
Diodes
DD
DIODES
(see table below)
PULL-UP
(see table below)
ALTERNATE
ANALOG
ST72321
to V
INPUT
INPUT
On
PAD
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