GD32VF103 User Manual
106
7.3.6.
Analog configuration
When GPIO pin is used as analog configuration:
The weak pull-up and pull-down resistors are disabled.
The output buffer is disabled.
The schmitt trigger input is disabled.
The port input status register of this I/O port bit is “0”.
Figure 7.4. Analog configuration
shows the analog configuration.
Figure 7.4. Analog configuration
Analog ( Input / Output )
I/O pin
ESD
protection
7.3.7.
Alternate function (AF) configuration
To suit for different device packages, the GPIO supports some alternate functions mapped to
some other pins by software.
When be configured as alternate function:
The output buffer is enabled in Open-Drain or Push-Pull configuration.
The output buffer is driven by the peripheral.
The schmitt trigger input is enabled.
The weak pull-up and pull-down resistors could be chosen when input.
The I/O pin data is stored into the port input status register every APB2 clock.
A read access to the port input status register gets the I/O state.
A read access to the port output control register gets the last written value.
Figure 7.5. Alternate function configuration
shows the alternate function configuration.
Figure 7.5. Alternate function configuration