{"id":2764,"date":"2025-07-24T18:18:47","date_gmt":"2025-07-24T17:18:47","guid":{"rendered":"https:\/\/workboot.fr\/ciela\/?page_id=2764"},"modified":"2025-07-25T14:40:26","modified_gmt":"2025-07-25T13:40:26","slug":"gpio-bcm-2837","status":"publish","type":"page","link":"https:\/\/workboot.fr\/ciela\/gpio-bcm-2837\/","title":{"rendered":"GPIO BCM 2837"},"content":{"rendered":"\n

Adresses de base des registres GPIO<\/strong><\/h1>\n\n\n\n

Sur le BCM2837, les registres GPIO sont mapp\u00e9s en m\u00e9moire \u00e0 partir de l\u2019adresse de base :
0x3F000000<\/code><\/strong> (contre 0x20000000<\/code> sur le BCM2835).
Les registres GPIO occupent une plage de 0x3F200000 \u00e0 0x3F2000B4<\/strong>.<\/p>\n\n\n\n

\n

Note<\/strong> :<\/p>\n\n\n\n

    \n
  • Sur le Pi 4 (BCM2711)<\/strong>, l\u2019adresse de base devient 0xFE000000<\/code><\/strong>.<\/li>\n\n\n\n
  • Toujours v\u00e9rifier le mod\u00e8le avec cat \/proc\/cpuinfo<\/code>.<\/li>\n<\/ul>\n<\/blockquote>\n\n\n\n

    Structure des registres GPIO cl\u00e9s<\/h1>\n\n\n\n

    Chaque registre fait 32 bits (4 octets). Voici les principaux :<\/p>\n\n\n\n

    Offset<\/strong><\/td>Registre<\/strong><\/td>Description<\/strong><\/td><\/tr>
    0x00 <\/td>GPFSEL0 \u00e0 GPFSEL5<\/td>Configuration des broches (entr\u00e9e\/sortie\/fonction alternative).<\/td><\/tr>
    0x1C<\/td>GPSET0 \/ GPSET1<\/td>Mettre une broche \u00e0 1 (activation).<\/td><\/tr>
    0x28<\/td>GPCLR0 \/ GPCLR1<\/td>Mettre une broche \u00e0 0 (d\u00e9sactivation).<\/td><\/tr>
    0x34<\/td>GPLEV0 \/ GPLEV1<\/td> Lire l\u2019\u00e9tat actuel d\u2019une broche (niveau haut\/bas).<\/td><\/tr>
    0x40<\/td>GPEDS0 \/ GPEDS1<\/td>D\u00e9tection d\u2019\u00e9v\u00e9nement (front montant\/descendant).<\/td><\/tr>
    0x7E<\/td>GPPUD<\/td>Configuration des r\u00e9sistances de pull-up\/pull-down.<\/td><\/tr>
    0x94<\/td>GPPUDCLK0\/GPPUDCLK1<\/td>0x94 GPPUDCLK0\/GPPUDCLK1 Activation du pull-up\/pull-down pour une broche sp\u00e9cifique.<\/td><\/tr><\/tbody><\/table>
    offset pour acc\u00e9der aux registres internes<\/figcaption><\/figure>\n\n\n\n

    D\u00e9tail des registres de fonction (GPFSEL)<\/strong><\/h2>\n\n\n\n

    Chaque registre GPFSEL0<\/code> \u00e0 GPFSEL5<\/code> contr\u00f4le 10 broches<\/strong> (3 bits par broche) :<\/p>\n\n\n\n

      \n
    • 000<\/strong> : Entr\u00e9e.<\/li>\n\n\n\n
    • 001<\/strong> : Sortie.<\/li>\n\n\n\n
    • 010 \u00e0 111<\/strong> : Fonction alternative (UART, SPI, I2C, etc.).<\/li>\n<\/ul>\n\n\n\n

      Exemple<\/strong> : Configurer la GPIO17<\/strong> (broche 11 du header) en sortie :<\/p>\n\n\n\n

        \n
      • La GPIO17 est g\u00e9r\u00e9e par GPFSEL1<\/code> (offset 0x04<\/code>).<\/li>\n\n\n\n
      • Bits 21-23<\/strong> dans GPFSEL1<\/code> doivent \u00eatre 001<\/code>.<\/li>\n<\/ul>\n\n\n\n
        \/\/ En C (acc\u00e8s direct m\u00e9moire) :\nvolatile unsigned int* gpio = (unsigned int*)0x3F200000;\n*(gpio + 1) |= (1 << 21); \/\/ GPFSEL1[21:23] = 001<\/code><\/pre>\n\n\n\n
        Activation\/d\u00e9sactivation des broches (GPSET\/GPCLR)<\/strong><\/h2>\n\n\n\n
          \n
        • GPSET0<\/strong> (offset 0x1C<\/code>) : \u00c9crire 1<\/code> pour activer une broche.<\/li>\n\n\n\n
        • GPCLR0<\/strong> (offset 0x28<\/code>) : \u00c9crire 1<\/code> pour d\u00e9sactiver une broche.<\/li>\n<\/ul>\n\n\n\n
          Exemple<\/strong> : Allumer la GPIO17<\/strong> :<\/p>\n\n\n\n
          *(gpio + 7) = (1 << 17); \/\/ GPSET0[17] = 1<\/code><\/pre>\n\n\n\n
          \u00c9teindre la GPIO17<\/strong> :<\/p>\n\n\n\n
          *(gpio + 10) = (1 << 17); \/\/ GPCLR0[17] = 1<\/code><\/pre>\n\n\n\n
          Lecture d\u2019une broche (GPLEV)<\/strong><\/h2>\n\n\n\n
          Pour lire l\u2019\u00e9tat de la GPIO17<\/strong> :<\/p>\n\n\n\n
          int state = (*(gpio + 13) >> 17) & 1; \/\/ GPLEV0[17]<\/code><\/pre>\n\n\n\n
          Pull-up\/pull-down (GPPUD et GPPUDCLK)<\/strong><\/h2>\n\n\n\n
          \u00c9crire la configuration dans GPPUD<\/code> (offset 0x94<\/code>) :<\/h3>\n\n\n\n
            \n
          • 0x00<\/code> : D\u00e9sactiver.<\/li>\n\n\n\n
          • 0x01<\/code> : Pull-down.<\/li>\n\n\n\n
          • 0x02<\/code> : Pull-up.<\/li>\n<\/ul>\n\n\n\n
            Activer la configuration pour une broche via GPPUDCLK0<\/code> (offset 0x98<\/code>).<\/h3>\n\n\n\n
            *(gpio + 37) = 0x02;       \/\/ GPPUD = pull-up\ndelay(150);                \/\/ Attendre 150 cycles\n*(gpio + 38) = (1 << 17);  \/\/ GPPUDCLK0[17] = 1\ndelay(150);\n*(gpio + 37) = 0x00;       \/\/ R\u00e9initialiser GPPUD\n*(gpio + 38) = 0x00;       \/\/ R\u00e9initialiser GPPUDCLK0<\/code><\/pre>\n\n\n\n
            Mapping des broches (Header 40 broches)<\/strong><\/h2>\n\n\n\n
            Broche<\/strong><\/th>GPIO<\/strong><\/th>Fonction alternative<\/strong><\/th><\/tr><\/thead>
            11<\/td>GPIO17<\/td>G\u00e9n\u00e9rique (sortie LED).<\/td><\/tr>
            12<\/td>GPIO18<\/td>PWM0.<\/td><\/tr>
            19<\/td>GPIO10<\/td>SPI0_MOSI.<\/td><\/tr>
            23<\/td>GPIO11<\/td>SPI0_SCLK.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
            Exemple complet en C (sans librairie)<\/strong><\/h2>\n\n\n\n
            #include <stdio.h>\n#include <stdlib.h>\n#include <fcntl.h>\n#include <sys\/mman.h>\n#include <unistd.h>\n\n\/\/ Adresses pour Raspberry Pi (\u00e0 ajuster selon mod\u00e8le)\n#define GPIO_BASE 0xFE200000 \/\/ RPi 4 (BCM2711)\n\/\/ #define GPIO_BASE 0x3F200000 \/\/ RPi 2\/3\n#define PAGE_SIZE 4096\n#define BLOCK_SIZE 4096\n\n\/\/ Registres GPIO\n#define GPFSEL0 0x00 \/\/ Fonction Select 0\n#define GPSET0  0x1C \/\/ Set Output\n#define GPCLR0  0x28 \/\/ Clear Output\n\nvolatile unsigned int *gpio;\n\nvoid init_gpio() {\n    int fd = open(\"\/dev\/gpiomem\", O_RDWR | O_SYNC);\n    if (fd < 0) {\n        perror(\"\u00c9chec de l'ouverture de \/dev\/gpiomem\");\n        exit(1);\n    }\n\n    gpio = (volatile unsigned int *)mmap(\n        NULL,\n        BLOCK_SIZE,\n        PROT_READ | PROT_WRITE,\n        MAP_SHARED,\n        fd,\n        GPIO_BASE\n    );\n    close(fd);\n\n    if (gpio == MAP_FAILED) {\n        perror(\"\u00c9chec du mmap\");\n        exit(1);\n    }\n}\n\nvoid set_gpio_output(int pin) {\n    int reg = pin \/ 10;\n    int shift = (pin % 10) * 3;\n    gpio[reg] = (gpio[reg] & ~(7 << shift)) | (1 << shift);\n}\n\nint main() {\n    int led_pin = 17; \/\/ GPIO17 (broche physique 11)\n\n    init_gpio();\n    set_gpio_output(led_pin);\n\n    while (1) {\n        gpio[GPSET0 \/ 4] = 1 << led_pin; \/\/ Allume\n        sleep(1);\n        gpio[GPCLR0 \/ 4] = 1 << led_pin; \/\/ \u00c9teint\n        sleep(1);\n    }\n\n    munmap((void *)gpio, BLOCK_SIZE);\n    return 0;\n}<\/code><\/pre>\n\n\n\n
            Pr\u00e9cautions<\/strong><\/h2>\n\n\n\n
              \n
            • Acc\u00e8s root requis<\/strong> : Utiliser \/dev\/mem<\/code> ou \/dev\/gpiomem<\/code>.<\/li>\n\n\n\n
            • Voltage<\/strong> : Les GPIO sont en 3,3 V<\/strong> (ne pas connecter du 5 V directement).<\/li>\n\n\n\n
            • Synchronisation<\/strong> : Toujours v\u00e9rifier les offsets et adresses pour le BCM2837.<\/li>\n<\/ul>\n\n\n","protected":false},"excerpt":{"rendered":"
              Adresses de base des registres GPIO Sur le BCM2837, les registres GPIO sont mapp\u00e9s en m\u00e9moire \u00e0 partir de l\u2019adresse de base :0x3F000000 (contre 0x20000000 sur le BCM2835).Les registres GPIO occupent une plage […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_crdt_document":"","_uag_custom_page_level_css":"","footnotes":""},"class_list":["post-2764","page","type-page","status-publish","hentry"],"yoast_head":"\nGPIO BCM 2837 - workboot<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/workboot.fr\/ciela\/gpio-bcm-2837\/\" \/>\n<meta property=\"og:locale\" content=\"fr_FR\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"GPIO BCM 2837 - workboot\" \/>\n<meta property=\"og:description\" content=\"Adresses de base des registres GPIO Sur le BCM2837, les registres GPIO sont mapp\u00e9s en m\u00e9moire \u00e0 partir de l\u2019adresse de base :0x3F000000 (contre 0x20000000 sur le BCM2835).Les registres GPIO occupent une plage […]\" \/>\n<meta property=\"og:url\" content=\"https:\/\/workboot.fr\/ciela\/gpio-bcm-2837\/\" \/>\n<meta property=\"og:site_name\" content=\"workboot\" \/>\n<meta property=\"article:modified_time\" content=\"2025-07-25T13:40:26+00:00\" \/>\n<meta name=\"twitter:label1\" content=\"Dur\u00e9e de lecture estim\u00e9e\" \/>\n\t<meta name=\"twitter:data1\" content=\"2 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/workboot.fr\\\/ciela\\\/gpio-bcm-2837\\\/\",\"url\":\"https:\\\/\\\/workboot.fr\\\/ciela\\\/gpio-bcm-2837\\\/\",\"name\":\"GPIO BCM 2837 - 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