The STM32 GPIO registers

In this section, we will explore the characteristics and functions of some of the common registers within the GPIO peripheral.

Each GPIO port includes a set of 32-bit registers essential for configuration and control. The configuration registers comprise the following:

• GPIOx_MODER (mode register)
• GPIOx_OTYPER (output type register)
• GPIOx_OSPEEDR (output speed register)
• GPIOx_PUPDR (pull-up/pull-down register)

The data registers include the following:

• GPIOx_IDR (input data register)
• GPIOx_ODR (output data register)

GPIOx_BSRR (the bit-set/reset register) and GPIOx_LCKR (the locking register) are used to control pin states and access. Additionally, the alternate function selection registers, GPIOx_AFRH and GPIOx_AFRL, manage the alternate function assignments for the pins within the GPIO port.

Let’s start with the GPIO mode register.

The GPIO mode register (GPIOx_MODER)

The GPIO port mode register...