STMicroelectronics STM32F407 User Manual

General-purpose I/Os (GPIO) RM0090
278/1731 DocID018909 Rev 11
Figure 28. Input floating/pull up/pull down configurations
8.3.10 Output configuration
When the I/O port is programmed as output:
• The output buffer is enabled:
– Open drain mode: A “0” in the Output register activates the N-MOS whereas a “1”
in the Output register leaves the port in Hi-Z (the P-MOS is never activated)
– Push-pull mode: A “0” in the Output register activates the N-MOS whereas a “1” in
the Output register activates the P-MOS
• 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
• A read access to the output data register gets the last written value
Figure 29 shows the output configuration of the I/O port bit.
ONOFF
PULL
PULL
ONOFF
)/PIN
6
$$
6
33
44,3CHMITT
TRIGGER
6
33
6
$$
PROTECTION
DIODE
PROTECTION
DIODE
ON
INPUTDRIVER
OUTPUTDRIVER
DOWN
UP
)NPUTDATAREGISTER
/UTPUTDATAREGISTER
2EADWRITE
2EAD
"ITSETRESETREGISTERS
7RITE
AIB

STMicroelectronics STM32F407 Specifications

General

Brand	STMicroelectronics
Model	STM32F407
Category	Controller
Language	English