Diff: targets/hal/TARGET_STM/TARGET_STM32F3XX/us_ticker.c

Revision:

155:8435094ec241

Child:

304:89b9c3a9a045

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/hal/TARGET_STM/TARGET_STM32F3XX/us_ticker.c	Tue Apr 08 09:15:06 2014 +0100
@@ -0,0 +1,81 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2014, STMicroelectronics
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. Neither the name of STMicroelectronics nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include <stddef.h>
+#include "us_ticker_api.h"
+#include "PeripheralNames.h"
+
+// 32-bit timer selection
+#define TIM_MST            TIM2
+#define TIM_MST_IRQ        TIM2_IRQn
+#define TIM_MST_RCC        RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE)
+
+static int us_ticker_inited = 0;
+
+void us_ticker_init(void) {
+    TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
+
+    if (us_ticker_inited) return;
+    us_ticker_inited = 1;
+
+    // Enable timer clock
+    TIM_MST_RCC;
+
+    // Configure time base
+    TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);
+    TIM_TimeBaseStructure.TIM_Period        = 0xFFFFFFFF;
+    TIM_TimeBaseStructure.TIM_Prescaler     = (uint16_t)(SystemCoreClock / 1000000) - 1; // 1 µs tick
+    TIM_TimeBaseStructure.TIM_ClockDivision = 0;
+    TIM_TimeBaseStructure.TIM_CounterMode   = TIM_CounterMode_Up;
+    TIM_TimeBaseInit(TIM_MST, &TIM_TimeBaseStructure);
+
+    NVIC_SetVector(TIM_MST_IRQ, (uint32_t)us_ticker_irq_handler);
+    NVIC_EnableIRQ(TIM_MST_IRQ);
+
+    // Enable timer
+    TIM_Cmd(TIM_MST, ENABLE);
+}
+
+uint32_t us_ticker_read() {
+    if (!us_ticker_inited) us_ticker_init();
+    return TIM_MST->CNT;
+}
+
+void us_ticker_set_interrupt(unsigned int timestamp) {
+    // Set new output compare value
+    TIM_SetCompare1(TIM_MST, timestamp);
+    // Enable IT
+    TIM_ITConfig(TIM_MST, TIM_IT_CC1, ENABLE);
+}
+
+void us_ticker_disable_interrupt(void) {
+    TIM_ITConfig(TIM_MST, TIM_IT_CC1, DISABLE);
+}
+
+void us_ticker_clear_interrupt(void) {
+    TIM_ClearITPendingBit(TIM_MST, TIM_IT_CC1);
+}