/* * This file is part of the libopenstm32 project. * * Copyright (C) 2009 Uwe Hermann * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see . */ #include /* Set STM32 to 72 MHz. */ void clock_setup(void) { /* Select HSI as SYSCLK source. */ rcc_set_sysclk_source(SW_SYSCLKSEL_HSICLK); /* Set the PLL multiplication factor to 9. */ rcc_set_pll_multiplication_factor(PLLMUL_PLL_CLK_MUL9); /* Select HSI/2 as PLL source. */ rcc_set_pll_source(PLLSRC_HSI_CLK_DIV2); rcc_set_pllxtpre(PLLXTPRE_HSE_CLK_DIV2); /* Enable PLL oscillator and wait for it to stabilize. */ rcc_osc_on(PLL); rcc_wait_for_osc_ready(PLL); /* Select PLL as SYSCLK source. */ rcc_set_sysclk_source(SW_SYSCLKSEL_PLLCLK); } void gpio_setup(void) { /* Enable GPIOC clock. */ rcc_peripheral_enable_clock(&RCC_APB2ENR, IOPCEN); /* Set GPIO12 (in GPIO port C) to 'output push-pull'. */ gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO12); } int main(void) { int i; clock_setup(); gpio_setup(); /* Blink the LED (PC12) on the board. */ while (1) { gpio_toggle(GPIOC, GPIO12); /* LED on/off */ for (i = 0; i < 80000; i++); /* Wait (needs -O0 CFLAGS). */ } return 0; }