Differences

This shows you the differences between two versions of the page.

--- stm32:peripherals:gpio_input [2016/02/25 08:52] – feur
+++ stm32:peripherals:gpio_input [2022/12/28 08:15] (current) – ruan
@@ Line 9: / Line 9: @@
 \\ {{gpio_input.svg}} \\ \\
-===== Programming example =====
+===== Programming Instructions =====
-The code snippet bellow shows how to configure and use a GPIO pin as input.
+==== Enable Peripheral ====
-<code c>
+Make sure the peripheral is enabled:
-#include "reg_stm32f4xx.h"
+  * Enable GPIOx in ''RCC->AHBENR[0]''.
-/* Configure GPIO pin A.10 as input. */
+==== Setup input mode ====
-GPIOA->MODER &= ~(0x3 << 20u);    /* Clear existing mode bits 20 and 21. */
-GPIOA->PUPDR &= ~(0x3 << 20u);    /* Clear existing pull-up/-down bits 20 and 21. */
+Configure the MODE and PUPDR register, for every pin that should act as digital input:
-GPIOA->PUPDR |= (0x1 << 20u);     /* Set pin 10 to pull-up mode. */
+  * Write ''0x00'' to the corresponding fields in ''GPIOx->MODE''.
+  * Configure pull-up / -down in ''GPIOx->PUPDR''.
-/* Read from GPIO pin A.10. */
-uint32_t data = GPIOA->IDR;       /* Read the input data register. */
-</code>
 \\
 ===== Configuration Registers =====
-==== MODER ====
+==== GPIOx_MODER - GPIO port mode register ====
-Mode register
 \\ {{gpio_reg_common.svg}} \\ \\
@@ Line 38: / Line 32: @@
 |Pin x|00|Input mode (reset state)|
-==== PUPDR ====
+==== GPIOx_PUPDR - GPIO port pull-up / pull-down register ====
-Push-up / pull-down register
 \\ {{gpio_reg_common.svg}} \\ \\
@@ Line 51: / Line 43: @@
 ===== Data Registers =====
-==== IDR ====
+==== GPIOx_IDR - Port input data register ====
-Input data register
 \\ {{gpio_reg_idr.svg}} \\ \\
-* Register is read only
+* Register is read only \\ \\
-===== Legend =====
-\\ {{legende.svg}} \\ \\