Diff: targets/cmsis/TARGET_STM/TARGET_STM32F4/TARGET_NUCLEO_F446RE/hal_tick.c

Revision:

613:bc40b8d2aec4

Parent:

553:063b9f2f393c

--- a/targets/cmsis/TARGET_STM/TARGET_STM32F4/TARGET_NUCLEO_F446RE/hal_tick.c	Tue Aug 18 15:00:09 2015 +0100
+++ b/targets/cmsis/TARGET_STM/TARGET_STM32F4/TARGET_NUCLEO_F446RE/hal_tick.c	Thu Aug 20 10:45:13 2015 +0100
@@ -6,7 +6,7 @@
   ******************************************************************************
   * @attention
   *
-  * <h2><center>&copy; COPYRIGHT 2014 STMicroelectronics</center></h2>
+  * <h2><center>&copy; COPYRIGHT 2015 STMicroelectronics</center></h2>
   *
   * Redistribution and use in source and binary forms, with or without modification,
   * are permitted provided that the following conditions are met:
@@ -34,6 +34,9 @@
   */
 #include "hal_tick.h"
 
+// 0=NO, 1=PB6 toggles at each tick
+#define DEBUG_TICK 0
+
 TIM_HandleTypeDef TimMasterHandle;
 uint32_t PreviousVal = 0;
 
@@ -55,7 +58,7 @@
             // Prepare next interrupt
             __HAL_TIM_SetCompare(&TimMasterHandle, TIM_CHANNEL_2, val + HAL_TICK_DELAY);
             PreviousVal = val;
-#if 0 // For DEBUG only
+#if DEBUG_TICK > 0
             HAL_GPIO_TogglePin(GPIOB, GPIO_PIN_6);
 #endif
         }
@@ -64,20 +67,33 @@
 
 // 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;
 
     // Reset timer
     TIM_MST_RESET_ON;
     TIM_MST_RESET_OFF;
-
-    // Update the SystemCoreClock variable
-    SystemCoreClockUpdate();
-
+  
     // Configure time base
     TimMasterHandle.Instance = TIM_MST;
     TimMasterHandle.Init.Period            = 0xFFFFFFFF;
-    TimMasterHandle.Init.Prescaler         = (uint32_t)(SystemCoreClock / 2 / 1000000) - 1; // 1 µs tick
+  
+    // 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;
@@ -95,7 +111,7 @@
     __HAL_TIM_SetCompare(&TimMasterHandle, TIM_CHANNEL_2, PreviousVal + HAL_TICK_DELAY);
     __HAL_TIM_ENABLE_IT(&TimMasterHandle, TIM_IT_CC2);
 
-#if 0 // For DEBUG only
+#if DEBUG_TICK > 0
     __GPIOB_CLK_ENABLE();
     GPIO_InitTypeDef GPIO_InitStruct;
     GPIO_InitStruct.Pin = GPIO_PIN_6;