GD32VF103 User Manual
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7.
General-purpose and alternate-function I/Os (GPIO
and AFIO)
7.1.
Overview
There are up to 80 general purpose I/O pins (GPIO), named PA0 ~ PA15, PB0 ~ PB15, PC0
~ PC15, PD0 ~ PD15 and PE0 ~ PE15 for the device to implement logic input/output functions.
Each GPIO port has related control and configuration registers to satisfy the requirements of
specific applications. The external interrupt on the GPIO pins of the device have related
control and configuration registers in the Interrupt/event Controller Unit (EXTI).
The GPIO ports are pin-shared with other alternative functions (AFs) to obtain maximum
flexibility on the package pins. The GPIO pins can be used as alternative functional pins by
configuring the corresponding registers regardless of the AF input or output pins.
Each of the GPIO pins can be configured by software as output (push-pull or open-drain),
input, peripheral alternate function or analog mode. Each GPIO pin can be configured as pull-
up, pull-down or no pull-up/pull-down. All GPIOs are high-current capable except for analog
mode.
7.2.
Characteristics
Input/output direction control.
Schmitt trigger input function enable control.
Each pin weak pull-up/pull-down function.
Output push-pull/open drain enable control.
Output set/reset control.
External interrupt with programmable trigger edge
– using EXTI configuration registers.
Analog input/output configuration.
Alternate function input/output configuration.
Port configuration lock.
7.3.
Function overview
Each of the general-purpose I/O ports can be configured as 8 modes: analog inputs, input
floating, input pull-down/pull-up, GPIO push-pull/open-drain or AFIO push-pull/open-drain
mode by two GPIO configuration registers (GPIOx_CTL0/GPIOx_CTL1), and two 32-bits data
registers (GPIOx_ISTAT and GPIOx_OCTL).
Table 7.1. GPIO configuration table
details.
Table 7.1. GPIO configuration table