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Improvement of ticker configuration

pull/1289/head
bcostm 2015-08-11 14:34:06 +02:00
parent 408927ec5a
commit 8b76967c29
1 changed files with 21 additions and 15 deletions
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36
libraries/mbed/targets/cmsis/TARGET_STM/TARGET_STM32F7/TARGET_DISCO_F746NG/hal_tick.c
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@ -34,7 +34,7 @@
*/
#include "hal_tick.h"
// Enable it to measure the tick period on ARDUINO-D2 pin (PG6)
// 0=NO, 1=PG6 toggles at each tick
#define DEBUG_TICK 0
TIM_HandleTypeDef TimMasterHandle;
@ -60,7 +60,7 @@ void timer_irq_handler(void) {
// Prepare next interrupt
__HAL_TIM_SetCompare(&TimMasterHandle, TIM_CHANNEL_2, val + HAL_TICK_DELAY);
PreviousVal = val;
#if DEBUG_TICK == 1
#if DEBUG_TICK > 0
HAL_GPIO_TogglePin(GPIOG, GPIO_PIN_6);
#endif
}
@ -69,6 +69,16 @@ void timer_irq_handler(void) {
// Reconfigure the HAL tick using a standard timer instead of systick.
HAL_StatusTypeDef HAL_InitTick(uint32_t TickPriority) {
RCC_ClkInitTypeDef RCC_ClkInitStruct;
uint32_t PclkFreq;
// Get clock configuration
// Note: PclkFreq contains here the Latency (not used after)
HAL_RCC_GetClockConfig(&RCC_ClkInitStruct, &PclkFreq);
// Get TIM5 clock value
PclkFreq = HAL_RCC_GetPCLK1Freq();
// Enable timer clock
TIM_MST_RCC;
@ -76,20 +86,16 @@ HAL_StatusTypeDef HAL_InitTick(uint32_t TickPriority) {
TIM_MST_RESET_ON;
TIM_MST_RESET_OFF;
// Just in case the system clock has been changed and the SystemCoreClock
// variable not updated...
SystemCoreClockUpdate();
// Note on timer clock:
// TIM5 input clock (TIM5CLK) is set to APB1 clock (PCLK1) x2,
// since APB1 prescaler is equal to 4 (see system_stm32f7xx.c).
// We have TIM5CLK = PCLK1*2 and PCLK1 = HCLK/4
// So TIM5CLK = HCLK/2 = SystemCoreClock/2
// Configure time base
TimMasterHandle.Instance = TIM_MST;
TimMasterHandle.Init.Period = 0xFFFFFFFF;
TimMasterHandle.Init.Prescaler = (uint32_t)((SystemCoreClock / 2) / 1000000) - 1; // 1 us tick
TimMasterHandle.Init.Period = 0xFFFFFFFF;
// TIMxCLK = PCLKx when the APB prescaler = 1 else TIMxCLK = 2 * PCLKx
if (RCC_ClkInitStruct.APB1CLKDivider == RCC_HCLK_DIV1)
TimMasterHandle.Init.Prescaler = (uint16_t)((PclkFreq) / 1000000) - 1; // 1 us tick
else
TimMasterHandle.Init.Prescaler = (uint16_t)((PclkFreq * 2) / 1000000) - 1; // 1 us tick
TimMasterHandle.Init.ClockDivision = 0;
TimMasterHandle.Init.CounterMode = TIM_COUNTERMODE_UP;
TimMasterHandle.Init.RepetitionCounter = 0;
@ -107,7 +113,7 @@ HAL_StatusTypeDef HAL_InitTick(uint32_t TickPriority) {
__HAL_TIM_SetCompare(&TimMasterHandle, TIM_CHANNEL_2, PreviousVal + HAL_TICK_DELAY);
__HAL_TIM_ENABLE_IT(&TimMasterHandle, TIM_IT_CC2);
#if DEBUG_TICK == 1
#if DEBUG_TICK > 0
__GPIOG_CLK_ENABLE();
GPIO_InitTypeDef GPIO_InitStruct;
GPIO_InitStruct.Pin = GPIO_PIN_6;