ST72F321 STMICROELECTRONICS [STMicroelectronics], ST72F321 Datasheet - Page 48

• 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]

ST72321
I/O PORTS (Cont’d)
Table 10. I/O Port Configurations
Notes:
1. When the I/O port is in input configuration and the associated alternate function is enabled as an output,
2. When the I/O port is in output configuration and the associated alternate function is enabled as an input,
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reading the DR register will read the alternate function output status.
the alternate function reads the pin status given by the DR register content.
NOT IMPLEMENTED IN
TRUE OPEN DRAIN
I/O PORTS
NOT IMPLEMENTED IN
TRUE OPEN DRAIN
I/O PORTS
NOT IMPLEMENTED IN
TRUE OPEN DRAIN
I/O PORTS
PAD
PAD
PAD
V
V
V
DD
R
DD
DD
R
R
PU
PU
PU
PULL-UP
CONDITION
Hardware Configuration
INTERRUPT
CONDITION
ALTERNATE
ALTERNATE
REGISTER
ENABLE
ENABLE
DR
DR REGISTER ACCESS
EXTERNAL INTERRUPT
SOURCE (ei
REGISTER
REGISTER
DR
DR
DR REGISTER ACCESS
DR REGISTER ACCESS
W
R
x
ALTERNATE
ALTERNATE
)
OUTPUT
OUTPUT
ALTERNATE INPUT
ANALOG INPUT
R/W
R/W
DATA BUS
DATA BUS
DATA BUS