STMicroelectronics STM32F407 User Manual

DocID018909 Rev 11 279/1731
RM0090 General-purpose I/Os (GPIO)
290
Figure 29. Output configuration
8.3.11 Alternate function configuration
When the I/O port is programmed as alternate function:
• The output buffer can be configured as open-drain or push-pull
• The output buffer is driven by the signal coming from the peripheral (transmitter enable
and data)
• The Schmitt trigger input is activated
• The weak pull-up and pull-down resistors are activated or not depending on the value
in the GPIOx_PUPDR register
• The data present on the I/O pin are sampled into the input data register every AHB1
clock cycle
• A read access to the input data register gets the I/O state
Figure 30 shows the Alternate function configuration of the I/O port bit.
Figure 30. Alternate function configuration
0USHPULLOR
/PENDRAIN
/UTPUT
CONTROL
6
$$
6
33
44,3CHMITT
TRIGGER
ON
)NPUTDRIVER
/UTPUTDRIVER
0-/3
.-/3
)NPUTDATAREGISTER
/UTPUTDATAREGISTER
2EADWRITE
2EAD
"ITSETRESETREGISTERS
7RITE
ONOFF
PULL
PULL
ONOFF
6
$$
6
33
6
33
6
$$
PROTECTION
DIODE
PROTECTION
DIODE
DOWN
UP
)/PIN
AIB
!LTERNATEFUNCTIONOUTPUT
!LTERNATEFUNCTIONINPUT
PUSHPULLOR
OPENDRAIN
&ROMONCHIP
PERIPHERAL
4OONCHIP
PERIPHERAL
/UTPUT
CONTROL
6
$$
6
33
44,3CHMITT
TRIGGER
ON
)NPUTDRIVER
/UTPUTDRIVER
0-/3
.-/3
)NPUTDATAREGISTER
/UTPUTDATAREGISTER
2EADWRITE
2EAD
"ITSETRESETREGISTERS
7RITE
ONOFF
ONOFF
6
$$
6
33
6
33
6
$$
PROTECTION
DIODE
PROTECTION
DIODE
0ULL
0ULL
)/PIN
DOWN
UP
AIB

STMicroelectronics STM32F407 Specifications

General

Brand	STMicroelectronics
Model	STM32F407
Category	Controller
Language	English