Differences

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--- stm32:peripherals:gpio_output [2016/02/25 08:25] – feur
+++ stm32:peripherals:gpio_output [2022/12/28 08:17] (current) – ruan
@@ Line 1: / Line 1: @@
 ====== General Purpose Output ======
-  * The [[OTYPER|output buffer]] is enabled (open drain or push-pull).
+  * The [[#OTYPER|output buffer]] is enabled (open drain or push-pull).
   * The Schmitt trigger input is active.
   * The pull-up and -down resistors are active, according to [[#registers|PUPDR]].
@@ Line 10: / Line 10: @@
 \\ {{gpio_output.svg}} \\ \\
-===== Programming example =====
+===== Programming Instructions =====
-The code snippet bellow shows how to configure and use a GPIO pin as output.
+==== Enable Peripheral ====
-<code c>
+Make sure the peripheral is enabled:
-#include "reg_stm32f4xx.h"
+  * Enable GPIOx in ''RCC->AHBENR[0]''.
-/* Configure GPIO pin A.5 as output. */
+==== Setup output mode ====
-GPIOA->MODER &= ~(0x3 << 10u);    /* Clear existing mode bits 10 and 11. */
-GPIOA->MODER |= (0x1 << 10u);     /* Set pin 10 to pull-up mode. */
-GPIOA->PUPDR &= ~(0x3 << 10u);    /* Clear existing pull-up/-down bits 10 and 11. */
+Configure the MODE and PUPDR as well as the output type and speed register, \\ for every pin that should act as digital output:
-GPIOA->PUPDR |= (0x2 << 10u);     /* Set pin 5 to pull-down mode. */
+  * Write ''0x01'' to the corresponding fields in ''GPIOx->MODE''.
+  * Configure pull-up / -down in ''GPIOx->PUPDR''.
-GPIOA->OTYPER &= ~(0x1 << 5u);    /* Clear existing output type bit 5. */
+  * Configure output type in ''GPIOx->OTYPER''. \\ (in conjunction with ''GPIOx->PUPDR'')
+  * Configure output speed in ''GPIOx->OSPEEDR''.
-GPIOA->OSPEEDR &= ~(0x3 << 10u);  /* Clear existing output speed bits 10 and 11. */
-GPIOA->OSPEEDR |= (0x1 << 10u);   /* Set pin 5 to medium speed (10 MHz) mode. */
-/* Write to GPIO pin A.5. */
-GPIOA->IDR |= (0x1 << 5u);        /* Write to data register. */
-GPIOA->BSRR[0] = (0x1 << 5u);     /* Directly set GPIO pin A.5. */
-GPIOA->BSRR[1] = (0x1 << 5u);     /* Directly clear GPIO pin A.5. */
-</code>
 \\
 ===== Configuration Registers =====
-==== MODER ====
+==== GPIOx_MODER - Port mode register ====
-Mode register
 \\ {{gpio_reg_common.svg}} \\ \\
-|< 100% 5em >|
+|< 100% 5em 5em >|
-|01|Output mode (reset state)|
+|Pin x|01|Output mode|
-==== PUPDR ====
+==== GPIOx_PUPDR - Port pull-up / pull-down register ====
-Push-up / pull-down register
 \\ {{gpio_reg_common.svg}} \\ \\
-|< 100% 5em >|
+|< 100% 5em 5em >|
-|00|No pull-up, pull-down (reset state)|
+|Pin x|00|No pull-up, pull-down (reset state)|
-|01|Pull-up|
+|:::|01|Pull-up|
-|10|Pull-down|
+|:::|10|Pull-down|
+|:::|11|Reserved|
-==== OTYPER ====
+==== GPIOx_OTYPER - Port output type register ====
-Output type register
 \\ {{gpio_reg_otyper.svg}} \\ \\
-|< 100% 5em >|
+|< 100% 5em 5em >|
-|0|Output type: push-pull (reset state)|
+|Pin x|0|Output type: push-pull (reset state)|
-|1|Output type: open-drain|
+|:::|1|Output type: open-drain|
-==== OSPEEDR ====
+==== GPIOx_OSPEEDR - Port output speed register ====
-Output speed register
 \\ {{gpio_reg_common.svg}} \\ \\
-|< 100% 5em >|
+|< 100% 5em 5em >|
-|00|Speed: 2 MHz (reset state)|
+|Pin x|00|Speed: 2 MHz (reset state)|
-|01|Speed: 10 MHz|
+|:::|01|Speed: 10 MHz|
-|10|Speed: 50 MHz|
+|:::|10|Speed: 50 MHz|
-|11|Speed: 100 MHz|
+|:::|11|Speed: 100 MHz|
 ===== Data Registers =====
-==== ODR ====
+==== GPIOx_ODR - Port output data register ====
-Output data register
 \\ {{gpio_reg_odr.svg}} \\ \\
-==== BSRR ====
+|< 100% 5em 5em >|
+|ODx|0|Clear/reset pin x|
+|:::|1|Set pin x|
-Bit set / reset register
+==== GPIOx_BSRR Port bit set / reset register ====
 \\ {{gpio_reg_bsrr.svg}} \\ \\
-|< 100% 5em >|
+|< 100% 5em 5em >|
-|BSx|Set pin x|
+|BSx|0|No effect|
-|BRx|Clear/reset pin x|
+|:::|1|Set pin x|
+|BRx|0|No effext|
-===== Legend =====
+|:::|1|Clear/reset pin x|
-\\ {{legende.svg}} \\ \\