From bcce98da54b047a15ef0abf41e0c7794f29f0439 Mon Sep 17 00:00:00 2001 From: Uwe Hermann Date: Thu, 30 Dec 2010 01:52:44 +0100 Subject: Move STM32 examples to examples/stm32 subdir. --- examples/stm32/other/timer_interrupt/timer.c | 85 ++++++++++++++++++++++++++++ 1 file changed, 85 insertions(+) create mode 100644 examples/stm32/other/timer_interrupt/timer.c (limited to 'examples/stm32/other/timer_interrupt/timer.c') diff --git a/examples/stm32/other/timer_interrupt/timer.c b/examples/stm32/other/timer_interrupt/timer.c new file mode 100644 index 0000000..d1f2bbb --- /dev/null +++ b/examples/stm32/other/timer_interrupt/timer.c @@ -0,0 +1,85 @@ +/* + * This file is part of the libopenstm32 project. + * + * Copyright (C) 2010 Thomas Otto + * + * 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 +#include +#include +#include +#include + +void gpio_setup(void) +{ + /* Enable GPIOB clock. */ + rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPBEN); + + /* Set GPIO6/7 (in GPIO port B) to 'output push-pull' for the LEDs. */ + gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_2_MHZ, + GPIO_CNF_OUTPUT_PUSHPULL, GPIO6); + gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_2_MHZ, + GPIO_CNF_OUTPUT_PUSHPULL, GPIO7); +} + +void nvic_setup() +{ + /* without this the timer interrupt routine will never be called */ + nvic_enable_irq(NVIC_TIM2_IRQ); + nvic_set_priority(NVIC_TIM2_IRQ, 1); +} + +void tim2_isr() +{ + /* LED2 on/off */ + gpio_toggle(GPIOB, GPIO6); + + /* clear interrrupt flag */ + TIM_SR(TIM2) &= ~TIM_SR_UIF; +} + +int main(void) +{ + rcc_clock_setup_in_hse_16mhz_out_72mhz(); + gpio_setup(); + nvic_setup(); + + gpio_clear(GPIOB, GPIO7); /* LED1 on */ + gpio_set(GPIOB, GPIO6); /* LED2 off */ + + rcc_peripheral_enable_clock(&RCC_APB1ENR, RCC_APB1ENR_TIM2EN); + + /* the goal is to let the LED2 glow for a second and then be off for a second */ + + /* Set timer start value */ + TIM_CNT(TIM2) = 1; + + /* Set timer prescaler. 72MHz/1440 => 50000 counts per second */ + TIM_PSC(TIM2) = 1440; + + /* End timer value. If this value is reached an interrupt is generated */ + TIM_ARR(TIM2) = 50000; + + /* Update interrupt enable */ + TIM_DIER(TIM2) |= TIM_DIER_UIE; + + /* Start timer */ + TIM_CR1(TIM2) |= TIM_CR1_CEN; + + while(1); /* Halt. */ + + return 0; +} -- cgit v1.2.3