ST STM32L0x3 User Manual

General-purpose I/Os (GPIO) RM0367
244/1043 RM0367 Rev 7
Figure 24 shows the output configuration of the I/O port bit.
Figure 24. Output configuration
9.3.11 Alternate function configuration
When the I/O port is programmed as alternate function:
• The output buffer can be configured in open-drain or push-pull mode
• The output buffer is driven by the signals 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 AHB
clock cycle
• A read access to the input data register gets the I/O state
Note: The alternate function configuration described above is not applied when the selected
alternate function is a LCD function. In this case, the I/O, programmed as an alternate
function output, is configured as described in the analog configuration.
Push-pull or
Open-drain
Output
control
V
DDIOx
V
SS
TTL Schmitt
trigger
on
Input driver
Output driver
P-MOS
N-MOS
Input data register
Output data register
Read/write
Read
Bit set/reset registers
Write
on/off
pull
pull
on/off
V
DDIOx
V
SS
V
SS
V
DDIOx
protection
diode
protection
diode
down
up
I/O pin
MS31478V1

ST STM32L0x3 Specifications

General

Brand	ST
Model	STM32L0x3
Category	Microcontrollers
Language	English