#include "FreeRTOS.h"\r
#include "task.h"\r
\r
-#if configMAX_SYSCALL_INTERRUPT_PRIORITY == 0\r
+#if( configMAX_SYSCALL_INTERRUPT_PRIORITY == 0 )\r
#error configMAX_SYSCALL_INTERRUPT_PRIORITY must not be set to 0. See http://www.FreeRTOS.org/RTOS-Cortex-M3-M4.html\r
#endif\r
\r
have bit-0 clear, as it is loaded into the PC on exit from an ISR. */\r
#define portSTART_ADDRESS_MASK ( ( StackType_t ) 0xfffffffeUL )\r
\r
-/* Required to allow portasm.asm access the configMAX_SYSCALL_INTERRUPT_PRIORITY\r
-setting. */\r
-const uint32_t ulMaxSyscallInterruptPriority = configMAX_SYSCALL_INTERRUPT_PRIORITY;\r
-\r
-/* Each task maintains its own interrupt status in the critical nesting\r
-variable. */\r
-static UBaseType_t uxCriticalNesting = 0xaaaaaaaa;\r
-\r
/*\r
* Setup the timer to generate the tick interrupts. The implementation in this\r
* file is weak to allow application writers to change the timer used to\r
\r
/*-----------------------------------------------------------*/\r
\r
+/* Required to allow portasm.asm access the configMAX_SYSCALL_INTERRUPT_PRIORITY\r
+setting. */\r
+const uint32_t ulMaxSyscallInterruptPriority = configMAX_SYSCALL_INTERRUPT_PRIORITY;\r
+\r
+/* Each task maintains its own interrupt status in the critical nesting\r
+variable. */\r
+static UBaseType_t uxCriticalNesting = 0xaaaaaaaa;\r
+\r
/*\r
* The number of SysTick increments that make up one tick period.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t ulTimerCountsForOneTick = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
* The maximum number of tick periods that can be suppressed is limited by the\r
* 24 bit resolution of the SysTick timer.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t xMaximumPossibleSuppressedTicks = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
* Compensate for the CPU cycles that pass while the SysTick is stopped (low\r
* power functionality only.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t ulStoppedTimerCompensation = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
}\r
/*-----------------------------------------------------------*/\r
\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
\r
#pragma WEAK( vPortSuppressTicksAndSleep )\r
void vPortSuppressTicksAndSleep( TickType_t xExpectedIdleTime )\r
{\r
- uint32_t ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickDecrements, ulSysTickCTRL;\r
+ uint32_t ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickDecrements;\r
TickType_t xModifiableIdleTime;\r
\r
/* Make sure the SysTick reload value does not overflow the counter. */\r
}\r
configPOST_SLEEP_PROCESSING( xExpectedIdleTime );\r
\r
- /* Stop SysTick. Again, the time the SysTick is stopped for is\r
- accounted for as best it can be, but using the tickless mode will\r
- inevitably result in some tiny drift of the time maintained by the\r
- kernel with respect to calendar time. */\r
- ulSysTickCTRL = portNVIC_SYSTICK_CTRL_REG;\r
- portNVIC_SYSTICK_CTRL_REG = ( ulSysTickCTRL & ~portNVIC_SYSTICK_ENABLE_BIT );\r
-\r
- /* Re-enable interrupts - see comments above __disable_interrupt()\r
- call above. */\r
+ /* Re-enable interrupts to allow the interrupt that brought the MCU\r
+ out of sleep mode to execute immediately. see comments above\r
+ __disable_interrupt() call above. */\r
__asm( " cpsie i" );\r
-\r
- if( ( ulSysTickCTRL & portNVIC_SYSTICK_COUNT_FLAG_BIT ) != 0 )\r
+ __asm( " dsb" );\r
+ __asm( " isb" );\r
+\r
+ /* Disable interrupts again because the clock is about to be stopped\r
+ and interrupts that execute while the clock is stopped will increase\r
+ any slippage between the time maintained by the RTOS and calendar\r
+ time. */\r
+ __asm( " cpsid i" );\r
+ __asm( " dsb" );\r
+ __asm( " isb" );\r
+\r
+ /* Disable the SysTick clock without reading the\r
+ portNVIC_SYSTICK_CTRL_REG register to ensure the\r
+ portNVIC_SYSTICK_COUNT_FLAG_BIT is not cleared if it is set. Again,\r
+ the time the SysTick is stopped for is accounted for as best it can\r
+ be, but using the tickless mode will inevitably result in some tiny\r
+ drift of the time maintained by the kernel with respect to calendar\r
+ time*/\r
+ portNVIC_SYSTICK_CTRL_REG = ( portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT );\r
+\r
+ /* Determine if the SysTick clock has already counted to zero and\r
+ been set back to the current reload value (the reload back being\r
+ correct for the entire expected idle time) or if the SysTick is yet\r
+ to count to zero (in which case an interrupt other than the SysTick\r
+ must have brought the system out of sleep mode). */\r
+ if( ( portNVIC_SYSTICK_CTRL_REG & portNVIC_SYSTICK_COUNT_FLAG_BIT ) != 0 )\r
{\r
uint32_t ulCalculatedLoadValue;\r
\r
- /* The tick interrupt has already executed, and the SysTick\r
- count reloaded with ulReloadValue. Reset the\r
+ /* The tick interrupt is already pending, and the SysTick count\r
+ reloaded with ulReloadValue. Reset the\r
portNVIC_SYSTICK_LOAD_REG with whatever remains of this tick\r
period. */\r
ulCalculatedLoadValue = ( ulTimerCountsForOneTick - 1UL ) - ( ulReloadValue - portNVIC_SYSTICK_CURRENT_VALUE_REG );\r
\r
portNVIC_SYSTICK_LOAD_REG = ulCalculatedLoadValue;\r
\r
- /* The tick interrupt handler will already have pended the tick\r
- processing in the kernel. As the pending tick will be\r
- processed as soon as this function exits, the tick value\r
- maintained by the tick is stepped forward by one less than the\r
- time spent waiting. */\r
+ /* As the pending tick will be processed as soon as this\r
+ function exits, the tick value maintained by the tick is stepped\r
+ forward by one less than the time spent waiting. */\r
ulCompleteTickPeriods = xExpectedIdleTime - 1UL;\r
}\r
else\r
\r
/* Restart SysTick so it runs from portNVIC_SYSTICK_LOAD_REG\r
again, then set portNVIC_SYSTICK_LOAD_REG back to its standard\r
- value. The critical section is used to ensure the tick interrupt\r
- can only execute once in the case that the reload register is near\r
- zero. */\r
+ value. */\r
portNVIC_SYSTICK_CURRENT_VALUE_REG = 0UL;\r
- portENTER_CRITICAL();\r
- {\r
- portNVIC_SYSTICK_CTRL_REG |= portNVIC_SYSTICK_ENABLE_BIT;\r
- vTaskStepTick( ulCompleteTickPeriods );\r
- portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;\r
- }\r
- portEXIT_CRITICAL();\r
+ portNVIC_SYSTICK_CTRL_REG |= portNVIC_SYSTICK_ENABLE_BIT;\r
+ vTaskStepTick( ulCompleteTickPeriods );\r
+ portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;\r
+\r
+ /* Exit with interrpts enabled. */\r
+ __asm( " cpsie i" );\r
}\r
}\r
\r
-#endif /* #if configUSE_TICKLESS_IDLE */\r
+#endif /* configUSE_TICKLESS_IDLE */\r
/*-----------------------------------------------------------*/\r
\r
/*\r
devices by calling NVIC_SetPriorityGrouping( 0 ); before starting the\r
scheduler. Note however that some vendor specific peripheral libraries\r
assume a non-zero priority group setting, in which cases using a value\r
- of zero will result in unpredicable behaviour. */\r
+ of zero will result in unpredictable behaviour. */\r
configASSERT( ( portAIRCR_REG & portPRIORITY_GROUP_MASK ) <= ulMaxPRIGROUPValue );\r
}\r
\r
#error This port can only be used when the project options are configured to enable hardware floating point support.\r
#endif\r
\r
-#if configMAX_SYSCALL_INTERRUPT_PRIORITY == 0\r
+#if( configMAX_SYSCALL_INTERRUPT_PRIORITY == 0 )\r
#error configMAX_SYSCALL_INTERRUPT_PRIORITY must not be set to 0. See http://www.FreeRTOS.org/RTOS-Cortex-M3-M4.html\r
#endif\r
\r
have bit-0 clear, as it is loaded into the PC on exit from an ISR. */\r
#define portSTART_ADDRESS_MASK ( ( StackType_t ) 0xfffffffeUL )\r
\r
-/* Required to allow portasm.asm access the configMAX_SYSCALL_INTERRUPT_PRIORITY\r
-setting. */\r
-const uint32_t ulMaxSyscallInterruptPriority = configMAX_SYSCALL_INTERRUPT_PRIORITY;\r
-\r
-/* Each task maintains its own interrupt status in the critical nesting\r
-variable. */\r
-static UBaseType_t uxCriticalNesting = 0xaaaaaaaa;\r
-\r
/*\r
* Setup the timer to generate the tick interrupts. The implementation in this\r
* file is weak to allow application writers to change the timer used to\r
\r
/*-----------------------------------------------------------*/\r
\r
+/* Required to allow portasm.asm access the configMAX_SYSCALL_INTERRUPT_PRIORITY\r
+setting. */\r
+const uint32_t ulMaxSyscallInterruptPriority = configMAX_SYSCALL_INTERRUPT_PRIORITY;\r
+\r
+/* Each task maintains its own interrupt status in the critical nesting\r
+variable. */\r
+static UBaseType_t uxCriticalNesting = 0xaaaaaaaa;\r
+\r
/*\r
* The number of SysTick increments that make up one tick period.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t ulTimerCountsForOneTick = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
* The maximum number of tick periods that can be suppressed is limited by the\r
* 24 bit resolution of the SysTick timer.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t xMaximumPossibleSuppressedTicks = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
* Compensate for the CPU cycles that pass while the SysTick is stopped (low\r
* power functionality only.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t ulStoppedTimerCompensation = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
}\r
/*-----------------------------------------------------------*/\r
\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
\r
#pragma WEAK( vPortSuppressTicksAndSleep )\r
void vPortSuppressTicksAndSleep( TickType_t xExpectedIdleTime )\r
{\r
- uint32_t ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickDecrements, ulSysTickCTRL;\r
+ uint32_t ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickDecrements;\r
TickType_t xModifiableIdleTime;\r
\r
/* Make sure the SysTick reload value does not overflow the counter. */\r
}\r
configPOST_SLEEP_PROCESSING( xExpectedIdleTime );\r
\r
- /* Stop SysTick. Again, the time the SysTick is stopped for is\r
- accounted for as best it can be, but using the tickless mode will\r
- inevitably result in some tiny drift of the time maintained by the\r
- kernel with respect to calendar time. */\r
- ulSysTickCTRL = portNVIC_SYSTICK_CTRL_REG;\r
- portNVIC_SYSTICK_CTRL_REG = ( ulSysTickCTRL & ~portNVIC_SYSTICK_ENABLE_BIT );\r
-\r
- /* Re-enable interrupts - see comments above __disable_interrupt()\r
- call above. */\r
+ /* Re-enable interrupts to allow the interrupt that brought the MCU\r
+ out of sleep mode to execute immediately. see comments above\r
+ __disable_interrupt() call above. */\r
__asm( " cpsie i" );\r
-\r
- if( ( ulSysTickCTRL & portNVIC_SYSTICK_COUNT_FLAG_BIT ) != 0 )\r
+ __asm( " dsb" );\r
+ __asm( " isb" );\r
+\r
+ /* Disable interrupts again because the clock is about to be stopped\r
+ and interrupts that execute while the clock is stopped will increase\r
+ any slippage between the time maintained by the RTOS and calendar\r
+ time. */\r
+ __asm( " cpsid i" );\r
+ __asm( " dsb" );\r
+ __asm( " isb" );\r
+\r
+ /* Disable the SysTick clock without reading the\r
+ portNVIC_SYSTICK_CTRL_REG register to ensure the\r
+ portNVIC_SYSTICK_COUNT_FLAG_BIT is not cleared if it is set. Again,\r
+ the time the SysTick is stopped for is accounted for as best it can\r
+ be, but using the tickless mode will inevitably result in some tiny\r
+ drift of the time maintained by the kernel with respect to calendar\r
+ time*/\r
+ portNVIC_SYSTICK_CTRL_REG = ( portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT );\r
+\r
+ /* Determine if the SysTick clock has already counted to zero and\r
+ been set back to the current reload value (the reload back being\r
+ correct for the entire expected idle time) or if the SysTick is yet\r
+ to count to zero (in which case an interrupt other than the SysTick\r
+ must have brought the system out of sleep mode). */\r
+ if( ( portNVIC_SYSTICK_CTRL_REG & portNVIC_SYSTICK_COUNT_FLAG_BIT ) != 0 )\r
{\r
uint32_t ulCalculatedLoadValue;\r
\r
- /* The tick interrupt has already executed, and the SysTick\r
- count reloaded with ulReloadValue. Reset the\r
+ /* The tick interrupt is already pending, and the SysTick count\r
+ reloaded with ulReloadValue. Reset the\r
portNVIC_SYSTICK_LOAD_REG with whatever remains of this tick\r
period. */\r
ulCalculatedLoadValue = ( ulTimerCountsForOneTick - 1UL ) - ( ulReloadValue - portNVIC_SYSTICK_CURRENT_VALUE_REG );\r
\r
portNVIC_SYSTICK_LOAD_REG = ulCalculatedLoadValue;\r
\r
- /* The tick interrupt handler will already have pended the tick\r
- processing in the kernel. As the pending tick will be\r
- processed as soon as this function exits, the tick value\r
- maintained by the tick is stepped forward by one less than the\r
- time spent waiting. */\r
+ /* As the pending tick will be processed as soon as this\r
+ function exits, the tick value maintained by the tick is stepped\r
+ forward by one less than the time spent waiting. */\r
ulCompleteTickPeriods = xExpectedIdleTime - 1UL;\r
}\r
else\r
\r
/* Restart SysTick so it runs from portNVIC_SYSTICK_LOAD_REG\r
again, then set portNVIC_SYSTICK_LOAD_REG back to its standard\r
- value. The critical section is used to ensure the tick interrupt\r
- can only execute once in the case that the reload register is near\r
- zero. */\r
+ value. */\r
portNVIC_SYSTICK_CURRENT_VALUE_REG = 0UL;\r
- portENTER_CRITICAL();\r
- {\r
- portNVIC_SYSTICK_CTRL_REG |= portNVIC_SYSTICK_ENABLE_BIT;\r
- vTaskStepTick( ulCompleteTickPeriods );\r
- portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;\r
- }\r
- portEXIT_CRITICAL();\r
+ portNVIC_SYSTICK_CTRL_REG |= portNVIC_SYSTICK_ENABLE_BIT;\r
+ vTaskStepTick( ulCompleteTickPeriods );\r
+ portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;\r
+\r
+ /* Exit with interrpts enabled. */\r
+ __asm( " cpsie i" );\r
}\r
}\r
\r
-#endif /* #if configUSE_TICKLESS_IDLE */\r
+#endif /* configUSE_TICKLESS_IDLE */\r
/*-----------------------------------------------------------*/\r
\r
/*\r
void vPortSetupTimerInterrupt( void )\r
{\r
/* Calculate the constants required to configure the tick interrupt. */\r
- #if configUSE_TICKLESS_IDLE == 1\r
+ #if( configUSE_TICKLESS_IDLE == 1 )\r
{\r
ulTimerCountsForOneTick = ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ );\r
xMaximumPossibleSuppressedTicks = portMAX_24_BIT_NUMBER / ulTimerCountsForOneTick;\r
devices by calling NVIC_SetPriorityGrouping( 0 ); before starting the\r
scheduler. Note however that some vendor specific peripheral libraries\r
assume a non-zero priority group setting, in which cases using a value\r
- of zero will result in unpredicable behaviour. */\r
+ of zero will result in unpredictable behaviour. */\r
configASSERT( ( portAIRCR_REG & portPRIORITY_GROUP_MASK ) <= ulMaxPRIGROUPValue );\r
}\r
\r
#define portTASK_RETURN_ADDRESS prvTaskExitError\r
#endif\r
\r
-/* Each task maintains its own interrupt status in the critical nesting\r
-variable. */\r
-static UBaseType_t uxCriticalNesting = 0xaaaaaaaa;\r
-\r
/*\r
* Setup the timer to generate the tick interrupts.\r
*/\r
\r
/*-----------------------------------------------------------*/\r
\r
+/* Each task maintains its own interrupt status in the critical nesting\r
+variable. */\r
+static UBaseType_t uxCriticalNesting = 0xaaaaaaaa;\r
+\r
+/*-----------------------------------------------------------*/\r
+\r
/*\r
* See header file for description.\r
*/\r
/* Should never get here as the tasks will now be executing! Call the task\r
exit error function to prevent compiler warnings about a static function\r
not being called in the case that the application writer overrides this\r
- functionality by defining configTASK_RETURN_ADDRESS. */\r
+ functionality by defining configTASK_RETURN_ADDRESS. Call\r
+ vTaskSwitchContext() so link time optimisation does not remove the\r
+ symbol. */\r
prvTaskExitError();\r
+ vTaskSwitchContext();\r
\r
/* Should not get here! */\r
return 0;\r
#define portTASK_RETURN_ADDRESS prvTaskExitError\r
#endif\r
\r
-/* Each task maintains its own interrupt status in the critical nesting\r
-variable. */\r
-static UBaseType_t uxCriticalNesting = 0xaaaaaaaa;\r
-\r
/*\r
* Setup the timer to generate the tick interrupts. The implementation in this\r
* file is weak to allow application writers to change the timer used to\r
\r
/*-----------------------------------------------------------*/\r
\r
+/* Each task maintains its own interrupt status in the critical nesting\r
+variable. */\r
+static UBaseType_t uxCriticalNesting = 0xaaaaaaaa;\r
+\r
/*\r
* The number of SysTick increments that make up one tick period.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t ulTimerCountsForOneTick = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
* The maximum number of tick periods that can be suppressed is limited by the\r
* 24 bit resolution of the SysTick timer.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t xMaximumPossibleSuppressedTicks = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
* Compensate for the CPU cycles that pass while the SysTick is stopped (low\r
* power functionality only.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t ulStoppedTimerCompensation = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
* FreeRTOS API functions are not called from interrupts that have been assigned\r
* a priority above configMAX_SYSCALL_INTERRUPT_PRIORITY.\r
*/\r
-#if ( configASSERT_DEFINED == 1 )\r
+#if( configASSERT_DEFINED == 1 )\r
static uint8_t ucMaxSysCallPriority = 0;\r
static uint32_t ulMaxPRIGROUPValue = 0;\r
static const volatile uint8_t * const pcInterruptPriorityRegisters = ( const volatile uint8_t * const ) portNVIC_IP_REGISTERS_OFFSET_16;\r
/* Should never get here as the tasks will now be executing! Call the task\r
exit error function to prevent compiler warnings about a static function\r
not being called in the case that the application writer overrides this\r
- functionality by defining configTASK_RETURN_ADDRESS. */\r
+ functionality by defining configTASK_RETURN_ADDRESS. Call\r
+ vTaskSwitchContext() so link time optimisation does not remove the\r
+ symbol. */\r
prvTaskExitError();\r
+ vTaskSwitchContext();\r
\r
/* Should not get here! */\r
return 0;\r
}\r
/*-----------------------------------------------------------*/\r
\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
\r
__attribute__((weak)) void vPortSuppressTicksAndSleep( TickType_t xExpectedIdleTime )\r
{\r
}\r
configPOST_SLEEP_PROCESSING( xExpectedIdleTime );\r
\r
- /* Re-enable interrupts - see comments above the cpsid instruction()\r
- above. */\r
+ /* Re-enable interrupts to allow the interrupt that brought the MCU\r
+ out of sleep mode to execute immediately. see comments above\r
+ __disable_interrupt() call above. */\r
__asm volatile( "cpsie i" ::: "memory" );\r
+ __asm volatile( "dsb" );\r
+ __asm volatile( "isb" );\r
+\r
+ /* Disable interrupts again because the clock is about to be stopped\r
+ and interrupts that execute while the clock is stopped will increase\r
+ any slippage between the time maintained by the RTOS and calendar\r
+ time. */\r
+ __asm volatile( "cpsid i" ::: "memory" );\r
+ __asm volatile( "dsb" );\r
+ __asm volatile( "isb" );\r
\r
/* Disable the SysTick clock without reading the\r
portNVIC_SYSTICK_CTRL_REG register to ensure the\r
- portNVIC_SYSTICK_COUNT_FLAG_BIT is not cleared if it is set. */\r
+ portNVIC_SYSTICK_COUNT_FLAG_BIT is not cleared if it is set. Again,\r
+ the time the SysTick is stopped for is accounted for as best it can\r
+ be, but using the tickless mode will inevitably result in some tiny\r
+ drift of the time maintained by the kernel with respect to calendar\r
+ time*/\r
portNVIC_SYSTICK_CTRL_REG = ( portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT );\r
\r
/* Determine if the SysTick clock has already counted to zero and\r
{\r
uint32_t ulCalculatedLoadValue;\r
\r
- /* The tick interrupt has already executed, and the SysTick\r
- count reloaded with ulReloadValue. Reset the\r
+ /* The tick interrupt is already pending, and the SysTick count\r
+ reloaded with ulReloadValue. Reset the\r
portNVIC_SYSTICK_LOAD_REG with whatever remains of this tick\r
period. */\r
ulCalculatedLoadValue = ( ulTimerCountsForOneTick - 1UL ) - ( ulReloadValue - portNVIC_SYSTICK_CURRENT_VALUE_REG );\r
\r
portNVIC_SYSTICK_LOAD_REG = ulCalculatedLoadValue;\r
\r
- /* The tick interrupt handler will already have pended the tick\r
- processing in the kernel. As the pending tick will be\r
- processed as soon as this function exits, the tick value\r
- maintained by the tick is stepped forward by one less than the\r
- time spent waiting. */\r
+ /* As the pending tick will be processed as soon as this\r
+ function exits, the tick value maintained by the tick is stepped\r
+ forward by one less than the time spent waiting. */\r
ulCompleteTickPeriods = xExpectedIdleTime - 1UL;\r
}\r
else\r
\r
/* Restart SysTick so it runs from portNVIC_SYSTICK_LOAD_REG\r
again, then set portNVIC_SYSTICK_LOAD_REG back to its standard\r
- value. The critical section is used to ensure the tick interrupt\r
- can only execute once in the case that the reload register is near\r
- zero. */\r
+ value. */\r
portNVIC_SYSTICK_CURRENT_VALUE_REG = 0UL;\r
- portENTER_CRITICAL();\r
- {\r
- portNVIC_SYSTICK_CTRL_REG |= portNVIC_SYSTICK_ENABLE_BIT;\r
- vTaskStepTick( ulCompleteTickPeriods );\r
- portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;\r
- }\r
- portEXIT_CRITICAL();\r
+ portNVIC_SYSTICK_CTRL_REG |= portNVIC_SYSTICK_ENABLE_BIT;\r
+ vTaskStepTick( ulCompleteTickPeriods );\r
+ portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;\r
+\r
+ /* Exit with interrpts enabled. */\r
+ __asm volatile( "cpsie i" ::: "memory" );\r
}\r
}\r
\r
-#endif /* #if configUSE_TICKLESS_IDLE */\r
+#endif /* configUSE_TICKLESS_IDLE */\r
/*-----------------------------------------------------------*/\r
\r
/*\r
__attribute__(( weak )) void vPortSetupTimerInterrupt( void )\r
{\r
/* Calculate the constants required to configure the tick interrupt. */\r
- #if configUSE_TICKLESS_IDLE == 1\r
+ #if( configUSE_TICKLESS_IDLE == 1 )\r
{\r
ulTimerCountsForOneTick = ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ );\r
xMaximumPossibleSuppressedTicks = portMAX_24_BIT_NUMBER / ulTimerCountsForOneTick;\r
devices by calling NVIC_SetPriorityGrouping( 0 ); before starting the\r
scheduler. Note however that some vendor specific peripheral libraries\r
assume a non-zero priority group setting, in which cases using a value\r
- of zero will result in unpredicable behaviour. */\r
+ of zero will result in unpredictable behaviour. */\r
configASSERT( ( portAIRCR_REG & portPRIORITY_GROUP_MASK ) <= ulMaxPRIGROUPValue );\r
}\r
\r
#define portTASK_RETURN_ADDRESS prvTaskExitError\r
#endif\r
\r
-/* Each task maintains its own interrupt status in the critical nesting\r
-variable. */\r
-static UBaseType_t uxCriticalNesting = 0xaaaaaaaa;\r
-\r
/*\r
* Setup the timer to generate the tick interrupts. The implementation in this\r
* file is weak to allow application writers to change the timer used to\r
\r
/*-----------------------------------------------------------*/\r
\r
+/* Each task maintains its own interrupt status in the critical nesting\r
+variable. */\r
+static UBaseType_t uxCriticalNesting = 0xaaaaaaaa;\r
+\r
/*\r
* The number of SysTick increments that make up one tick period.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t ulTimerCountsForOneTick = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
* The maximum number of tick periods that can be suppressed is limited by the\r
* 24 bit resolution of the SysTick timer.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t xMaximumPossibleSuppressedTicks = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
* Compensate for the CPU cycles that pass while the SysTick is stopped (low\r
* power functionality only.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t ulStoppedTimerCompensation = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
* FreeRTOS API functions are not called from interrupts that have been assigned\r
* a priority above configMAX_SYSCALL_INTERRUPT_PRIORITY.\r
*/\r
-#if ( configASSERT_DEFINED == 1 )\r
+#if( configASSERT_DEFINED == 1 )\r
static uint8_t ucMaxSysCallPriority = 0;\r
static uint32_t ulMaxPRIGROUPValue = 0;\r
static const volatile uint8_t * const pcInterruptPriorityRegisters = ( const volatile uint8_t * const ) portNVIC_IP_REGISTERS_OFFSET_16;\r
/* Should never get here as the tasks will now be executing! Call the task\r
exit error function to prevent compiler warnings about a static function\r
not being called in the case that the application writer overrides this\r
- functionality by defining configTASK_RETURN_ADDRESS. */\r
+ functionality by defining configTASK_RETURN_ADDRESS. Call\r
+ vTaskSwitchContext() so link time optimisation does not remove the\r
+ symbol. */\r
prvTaskExitError();\r
+ vTaskSwitchContext();\r
\r
/* Should not get here! */\r
return 0;\r
}\r
/*-----------------------------------------------------------*/\r
\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
\r
__attribute__((weak)) void vPortSuppressTicksAndSleep( TickType_t xExpectedIdleTime )\r
{\r
- uint32_t ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickDecrements, ulSysTickCTRL;\r
+ uint32_t ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickDecrements;\r
TickType_t xModifiableIdleTime;\r
\r
/* Make sure the SysTick reload value does not overflow the counter. */\r
}\r
configPOST_SLEEP_PROCESSING( xExpectedIdleTime );\r
\r
- /* Stop SysTick. Again, the time the SysTick is stopped for is\r
- accounted for as best it can be, but using the tickless mode will\r
- inevitably result in some tiny drift of the time maintained by the\r
- kernel with respect to calendar time. */\r
- ulSysTickCTRL = portNVIC_SYSTICK_CTRL_REG;\r
- portNVIC_SYSTICK_CTRL_REG = ( ulSysTickCTRL & ~portNVIC_SYSTICK_ENABLE_BIT );\r
-\r
- /* Re-enable interrupts - see comments above the cpsid instruction()\r
- above. */\r
+ /* Re-enable interrupts to allow the interrupt that brought the MCU\r
+ out of sleep mode to execute immediately. see comments above\r
+ __disable_interrupt() call above. */\r
__asm volatile( "cpsie i" ::: "memory" );\r
-\r
- if( ( ulSysTickCTRL & portNVIC_SYSTICK_COUNT_FLAG_BIT ) != 0 )\r
+ __asm volatile( "dsb" );\r
+ __asm volatile( "isb" );\r
+\r
+ /* Disable interrupts again because the clock is about to be stopped\r
+ and interrupts that execute while the clock is stopped will increase\r
+ any slippage between the time maintained by the RTOS and calendar\r
+ time. */\r
+ __asm volatile( "cpsid i" ::: "memory" );\r
+ __asm volatile( "dsb" );\r
+ __asm volatile( "isb" );\r
+\r
+ /* Disable the SysTick clock without reading the\r
+ portNVIC_SYSTICK_CTRL_REG register to ensure the\r
+ portNVIC_SYSTICK_COUNT_FLAG_BIT is not cleared if it is set. Again,\r
+ the time the SysTick is stopped for is accounted for as best it can\r
+ be, but using the tickless mode will inevitably result in some tiny\r
+ drift of the time maintained by the kernel with respect to calendar\r
+ time*/\r
+ portNVIC_SYSTICK_CTRL_REG = ( portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT );\r
+\r
+ /* Determine if the SysTick clock has already counted to zero and\r
+ been set back to the current reload value (the reload back being\r
+ correct for the entire expected idle time) or if the SysTick is yet\r
+ to count to zero (in which case an interrupt other than the SysTick\r
+ must have brought the system out of sleep mode). */\r
+ if( ( portNVIC_SYSTICK_CTRL_REG & portNVIC_SYSTICK_COUNT_FLAG_BIT ) != 0 )\r
{\r
uint32_t ulCalculatedLoadValue;\r
\r
- /* The tick interrupt has already executed, and the SysTick\r
- count reloaded with ulReloadValue. Reset the\r
+ /* The tick interrupt is already pending, and the SysTick count\r
+ reloaded with ulReloadValue. Reset the\r
portNVIC_SYSTICK_LOAD_REG with whatever remains of this tick\r
period. */\r
ulCalculatedLoadValue = ( ulTimerCountsForOneTick - 1UL ) - ( ulReloadValue - portNVIC_SYSTICK_CURRENT_VALUE_REG );\r
\r
portNVIC_SYSTICK_LOAD_REG = ulCalculatedLoadValue;\r
\r
- /* The tick interrupt handler will already have pended the tick\r
- processing in the kernel. As the pending tick will be\r
- processed as soon as this function exits, the tick value\r
- maintained by the tick is stepped forward by one less than the\r
- time spent waiting. */\r
+ /* As the pending tick will be processed as soon as this\r
+ function exits, the tick value maintained by the tick is stepped\r
+ forward by one less than the time spent waiting. */\r
ulCompleteTickPeriods = xExpectedIdleTime - 1UL;\r
}\r
else\r
\r
/* Restart SysTick so it runs from portNVIC_SYSTICK_LOAD_REG\r
again, then set portNVIC_SYSTICK_LOAD_REG back to its standard\r
- value. The critical section is used to ensure the tick interrupt\r
- can only execute once in the case that the reload register is near\r
- zero. */\r
+ value. */\r
portNVIC_SYSTICK_CURRENT_VALUE_REG = 0UL;\r
- portENTER_CRITICAL();\r
- {\r
- portNVIC_SYSTICK_CTRL_REG |= portNVIC_SYSTICK_ENABLE_BIT;\r
- vTaskStepTick( ulCompleteTickPeriods );\r
- portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;\r
- }\r
- portEXIT_CRITICAL();\r
+ portNVIC_SYSTICK_CTRL_REG |= portNVIC_SYSTICK_ENABLE_BIT;\r
+ vTaskStepTick( ulCompleteTickPeriods );\r
+ portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;\r
+\r
+ /* Exit with interrpts enabled. */\r
+ __asm volatile( "cpsie i" ::: "memory" );\r
}\r
}\r
\r
__attribute__(( weak )) void vPortSetupTimerInterrupt( void )\r
{\r
/* Calculate the constants required to configure the tick interrupt. */\r
- #if configUSE_TICKLESS_IDLE == 1\r
+ #if( configUSE_TICKLESS_IDLE == 1 )\r
{\r
ulTimerCountsForOneTick = ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ );\r
xMaximumPossibleSuppressedTicks = portMAX_24_BIT_NUMBER / ulTimerCountsForOneTick;\r
devices by calling NVIC_SetPriorityGrouping( 0 ); before starting the\r
scheduler. Note however that some vendor specific peripheral libraries\r
assume a non-zero priority group setting, in which cases using a value\r
- of zero will result in unpredicable behaviour. */\r
+ of zero will result in unpredictable behaviour. */\r
configASSERT( ( portAIRCR_REG & portPRIORITY_GROUP_MASK ) <= ulMaxPRIGROUPValue );\r
}\r
\r
#define portVECTACTIVE_MASK ( 0xFFUL )\r
\r
/* Constants required to manipulate the VFP. */\r
-#define portFPCCR ( ( volatile uint32_t * ) 0xe000ef34 ) /* Floating point context control register. */\r
-#define portASPEN_AND_LSPEN_BITS ( 0x3UL << 30UL )\r
+#define portFPCCR ( ( volatile uint32_t * ) 0xe000ef34 ) /* Floating point context control register. */\r
+#define portASPEN_AND_LSPEN_BITS ( 0x3UL << 30UL )\r
\r
/* Constants required to set up the initial stack. */\r
-#define portINITIAL_XPSR ( 0x01000000 )\r
-#define portINITIAL_EXEC_RETURN ( 0xfffffffd )\r
+#define portINITIAL_XPSR ( 0x01000000 )\r
+#define portINITIAL_EXEC_RETURN ( 0xfffffffd )\r
\r
/* The systick is a 24-bit counter. */\r
#define portMAX_24_BIT_NUMBER ( 0xffffffUL )\r
\r
+/* For strict compliance with the Cortex-M spec the task start address should\r
+have bit-0 clear, as it is loaded into the PC on exit from an ISR. */\r
+#define portSTART_ADDRESS_MASK ( ( StackType_t ) 0xfffffffeUL )\r
+\r
/* A fiddle factor to estimate the number of SysTick counts that would have\r
occurred while the SysTick counter is stopped during tickless idle\r
calculations. */\r
#define portMISSED_COUNTS_FACTOR ( 45UL )\r
\r
-/* For strict compliance with the Cortex-M spec the task start address should\r
-have bit-0 clear, as it is loaded into the PC on exit from an ISR. */\r
-#define portSTART_ADDRESS_MASK ( ( StackType_t ) 0xfffffffeUL )\r
-\r
/* Let the user override the pre-loading of the initial LR with the address of\r
prvTaskExitError() in case it messes up unwinding of the stack in the\r
debugger. */\r
#define portTASK_RETURN_ADDRESS prvTaskExitError\r
#endif\r
\r
-/* Each task maintains its own interrupt status in the critical nesting\r
-variable. */\r
-static UBaseType_t uxCriticalNesting = 0xaaaaaaaa;\r
-\r
/*\r
* Setup the timer to generate the tick interrupts. The implementation in this\r
* file is weak to allow application writers to change the timer used to\r
/*\r
* Function to enable the VFP.\r
*/\r
- static void vPortEnableVFP( void ) __attribute__ (( naked ));\r
+static void vPortEnableVFP( void ) __attribute__ (( naked ));\r
\r
/*\r
* Used to catch tasks that attempt to return from their implementing function.\r
\r
/*-----------------------------------------------------------*/\r
\r
+/* Each task maintains its own interrupt status in the critical nesting\r
+variable. */\r
+static UBaseType_t uxCriticalNesting = 0xaaaaaaaa;\r
+\r
/*\r
* The number of SysTick increments that make up one tick period.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t ulTimerCountsForOneTick = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
* The maximum number of tick periods that can be suppressed is limited by the\r
* 24 bit resolution of the SysTick timer.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t xMaximumPossibleSuppressedTicks = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
* Compensate for the CPU cycles that pass while the SysTick is stopped (low\r
* power functionality only.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t ulStoppedTimerCompensation = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
* FreeRTOS API functions are not called from interrupts that have been assigned\r
* a priority above configMAX_SYSCALL_INTERRUPT_PRIORITY.\r
*/\r
-#if ( configASSERT_DEFINED == 1 )\r
+#if( configASSERT_DEFINED == 1 )\r
static uint8_t ucMaxSysCallPriority = 0;\r
static uint32_t ulMaxPRIGROUPValue = 0;\r
static const volatile uint8_t * const pcInterruptPriorityRegisters = ( const volatile uint8_t * const ) portNVIC_IP_REGISTERS_OFFSET_16;\r
/* Should never get here as the tasks will now be executing! Call the task\r
exit error function to prevent compiler warnings about a static function\r
not being called in the case that the application writer overrides this\r
- functionality by defining configTASK_RETURN_ADDRESS. */\r
+ functionality by defining configTASK_RETURN_ADDRESS. Call\r
+ vTaskSwitchContext() so link time optimisation does not remove the\r
+ symbol. */\r
prvTaskExitError();\r
+ vTaskSwitchContext();\r
\r
/* Should not get here! */\r
return 0;\r
}\r
/*-----------------------------------------------------------*/\r
\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
\r
__attribute__((weak)) void vPortSuppressTicksAndSleep( TickType_t xExpectedIdleTime )\r
{\r
- uint32_t ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickDecrements, ulSysTickCTRL;\r
+ uint32_t ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickDecrements;\r
TickType_t xModifiableIdleTime;\r
\r
/* Make sure the SysTick reload value does not overflow the counter. */\r
}\r
configPOST_SLEEP_PROCESSING( xExpectedIdleTime );\r
\r
- /* Stop SysTick. Again, the time the SysTick is stopped for is\r
- accounted for as best it can be, but using the tickless mode will\r
- inevitably result in some tiny drift of the time maintained by the\r
- kernel with respect to calendar time. */\r
- ulSysTickCTRL = portNVIC_SYSTICK_CTRL_REG;\r
- portNVIC_SYSTICK_CTRL_REG = ( ulSysTickCTRL & ~portNVIC_SYSTICK_ENABLE_BIT );\r
-\r
- /* Re-enable interrupts - see comments above the cpsid instruction()\r
- above. */\r
+ /* Re-enable interrupts to allow the interrupt that brought the MCU\r
+ out of sleep mode to execute immediately. see comments above\r
+ __disable_interrupt() call above. */\r
__asm volatile( "cpsie i" ::: "memory" );\r
-\r
- if( ( ulSysTickCTRL & portNVIC_SYSTICK_COUNT_FLAG_BIT ) != 0 )\r
+ __asm volatile( "dsb" );\r
+ __asm volatile( "isb" );\r
+\r
+ /* Disable interrupts again because the clock is about to be stopped\r
+ and interrupts that execute while the clock is stopped will increase\r
+ any slippage between the time maintained by the RTOS and calendar\r
+ time. */\r
+ __asm volatile( "cpsid i" ::: "memory" );\r
+ __asm volatile( "dsb" );\r
+ __asm volatile( "isb" );\r
+\r
+ /* Disable the SysTick clock without reading the\r
+ portNVIC_SYSTICK_CTRL_REG register to ensure the\r
+ portNVIC_SYSTICK_COUNT_FLAG_BIT is not cleared if it is set. Again,\r
+ the time the SysTick is stopped for is accounted for as best it can\r
+ be, but using the tickless mode will inevitably result in some tiny\r
+ drift of the time maintained by the kernel with respect to calendar\r
+ time*/\r
+ portNVIC_SYSTICK_CTRL_REG = ( portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT );\r
+\r
+ /* Determine if the SysTick clock has already counted to zero and\r
+ been set back to the current reload value (the reload back being\r
+ correct for the entire expected idle time) or if the SysTick is yet\r
+ to count to zero (in which case an interrupt other than the SysTick\r
+ must have brought the system out of sleep mode). */\r
+ if( ( portNVIC_SYSTICK_CTRL_REG & portNVIC_SYSTICK_COUNT_FLAG_BIT ) != 0 )\r
{\r
uint32_t ulCalculatedLoadValue;\r
\r
- /* The tick interrupt has already executed, and the SysTick\r
- count reloaded with ulReloadValue. Reset the\r
+ /* The tick interrupt is already pending, and the SysTick count\r
+ reloaded with ulReloadValue. Reset the\r
portNVIC_SYSTICK_LOAD_REG with whatever remains of this tick\r
period. */\r
ulCalculatedLoadValue = ( ulTimerCountsForOneTick - 1UL ) - ( ulReloadValue - portNVIC_SYSTICK_CURRENT_VALUE_REG );\r
\r
portNVIC_SYSTICK_LOAD_REG = ulCalculatedLoadValue;\r
\r
- /* The tick interrupt handler will already have pended the tick\r
- processing in the kernel. As the pending tick will be\r
- processed as soon as this function exits, the tick value\r
- maintained by the tick is stepped forward by one less than the\r
- time spent waiting. */\r
+ /* As the pending tick will be processed as soon as this\r
+ function exits, the tick value maintained by the tick is stepped\r
+ forward by one less than the time spent waiting. */\r
ulCompleteTickPeriods = xExpectedIdleTime - 1UL;\r
}\r
else\r
\r
/* Restart SysTick so it runs from portNVIC_SYSTICK_LOAD_REG\r
again, then set portNVIC_SYSTICK_LOAD_REG back to its standard\r
- value. The critical section is used to ensure the tick interrupt\r
- can only execute once in the case that the reload register is near\r
- zero. */\r
+ value. */\r
portNVIC_SYSTICK_CURRENT_VALUE_REG = 0UL;\r
- portENTER_CRITICAL();\r
- {\r
- portNVIC_SYSTICK_CTRL_REG |= portNVIC_SYSTICK_ENABLE_BIT;\r
- vTaskStepTick( ulCompleteTickPeriods );\r
- portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;\r
- }\r
- portEXIT_CRITICAL();\r
+ portNVIC_SYSTICK_CTRL_REG |= portNVIC_SYSTICK_ENABLE_BIT;\r
+ vTaskStepTick( ulCompleteTickPeriods );\r
+ portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;\r
+\r
+ /* Exit with interrpts enabled. */\r
+ __asm volatile( "cpsie i" ::: "memory" );\r
}\r
}\r
\r
__attribute__(( weak )) void vPortSetupTimerInterrupt( void )\r
{\r
/* Calculate the constants required to configure the tick interrupt. */\r
- #if configUSE_TICKLESS_IDLE == 1\r
+ #if( configUSE_TICKLESS_IDLE == 1 )\r
{\r
ulTimerCountsForOneTick = ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ );\r
xMaximumPossibleSuppressedTicks = portMAX_24_BIT_NUMBER / ulTimerCountsForOneTick;\r
devices by calling NVIC_SetPriorityGrouping( 0 ); before starting the\r
scheduler. Note however that some vendor specific peripheral libraries\r
assume a non-zero priority group setting, in which cases using a value\r
- of zero will result in unpredicable behaviour. */\r
+ of zero will result in unpredictable behaviour. */\r
configASSERT( ( portAIRCR_REG & portPRIORITY_GROUP_MASK ) <= ulMaxPRIGROUPValue );\r
}\r
\r
#include "FreeRTOS.h"\r
#include "task.h"\r
\r
-#if configMAX_SYSCALL_INTERRUPT_PRIORITY == 0\r
+#if( configMAX_SYSCALL_INTERRUPT_PRIORITY == 0 )\r
#error configMAX_SYSCALL_INTERRUPT_PRIORITY must not be set to 0. See http://www.FreeRTOS.org/RTOS-Cortex-M3-M4.html\r
#endif\r
\r
#define configKERNEL_INTERRUPT_PRIORITY 255\r
#endif\r
\r
-/* Each task maintains its own interrupt status in the critical nesting\r
-variable. */\r
-static UBaseType_t uxCriticalNesting = 0xaaaaaaaa;\r
-\r
/*\r
* Setup the timer to generate the tick interrupts. The implementation in this\r
* file is weak to allow application writers to change the timer used to\r
\r
/*-----------------------------------------------------------*/\r
\r
+/* Each task maintains its own interrupt status in the critical nesting\r
+variable. */\r
+static UBaseType_t uxCriticalNesting = 0xaaaaaaaa;\r
+\r
/*\r
* The number of SysTick increments that make up one tick period.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t ulTimerCountsForOneTick = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
* The maximum number of tick periods that can be suppressed is limited by the\r
* 24 bit resolution of the SysTick timer.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t xMaximumPossibleSuppressedTicks = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
* Compensate for the CPU cycles that pass while the SysTick is stopped (low\r
* power functionality only.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t ulStoppedTimerCompensation = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
* FreeRTOS API functions are not called from interrupts that have been assigned\r
* a priority above configMAX_SYSCALL_INTERRUPT_PRIORITY.\r
*/\r
-#if ( configASSERT_DEFINED == 1 )\r
+#if( configASSERT_DEFINED == 1 )\r
static uint8_t ucMaxSysCallPriority = 0;\r
static uint32_t ulMaxPRIGROUPValue = 0;\r
static const volatile uint8_t * const pcInterruptPriorityRegisters = ( const volatile uint8_t * const ) portNVIC_IP_REGISTERS_OFFSET_16;\r
*/\r
BaseType_t xPortStartScheduler( void )\r
{\r
+ /* configMAX_SYSCALL_INTERRUPT_PRIORITY must not be set to 0.\r
+ See http://www.FreeRTOS.org/RTOS-Cortex-M3-M4.html */\r
+ configASSERT( configMAX_SYSCALL_INTERRUPT_PRIORITY );\r
+\r
#if( configASSERT_DEFINED == 1 )\r
{\r
volatile uint32_t ulOriginalPriority;\r
}\r
/*-----------------------------------------------------------*/\r
\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
\r
__weak void vPortSuppressTicksAndSleep( TickType_t xExpectedIdleTime )\r
{\r
- uint32_t ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickDecrements, ulSysTickCTRL;\r
+ uint32_t ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickDecrements;\r
TickType_t xModifiableIdleTime;\r
\r
/* Make sure the SysTick reload value does not overflow the counter. */\r
__DSB();\r
__ISB();\r
\r
-\r
/* If a context switch is pending or a task is waiting for the scheduler\r
to be unsuspended then abandon the low power entry. */\r
if( eTaskConfirmSleepModeStatus() == eAbortSleep )\r
}\r
configPOST_SLEEP_PROCESSING( xExpectedIdleTime );\r
\r
- /* Stop SysTick. Again, the time the SysTick is stopped for is\r
- accounted for as best it can be, but using the tickless mode will\r
- inevitably result in some tiny drift of the time maintained by the\r
- kernel with respect to calendar time. */\r
- ulSysTickCTRL = portNVIC_SYSTICK_CTRL_REG;\r
- portNVIC_SYSTICK_CTRL_REG = ( ulSysTickCTRL & ~portNVIC_SYSTICK_ENABLE_BIT );\r
-\r
- /* Re-enable interrupts - see comments above __disable_interrupt()\r
- call above. */\r
+ /* Re-enable interrupts to allow the interrupt that brought the MCU\r
+ out of sleep mode to execute immediately. see comments above\r
+ __disable_interrupt() call above. */\r
__enable_interrupt();\r
-\r
- if( ( ulSysTickCTRL & portNVIC_SYSTICK_COUNT_FLAG_BIT ) != 0 )\r
+ __DSB();\r
+ __ISB();\r
+\r
+ /* Disable interrupts again because the clock is about to be stopped\r
+ and interrupts that execute while the clock is stopped will increase\r
+ any slippage between the time maintained by the RTOS and calendar\r
+ time. */\r
+ __disable_interrupt();\r
+ __DSB();\r
+ __ISB();\r
+ \r
+ /* Disable the SysTick clock without reading the \r
+ portNVIC_SYSTICK_CTRL_REG register to ensure the\r
+ portNVIC_SYSTICK_COUNT_FLAG_BIT is not cleared if it is set. Again, \r
+ the time the SysTick is stopped for is accounted for as best it can \r
+ be, but using the tickless mode will inevitably result in some tiny \r
+ drift of the time maintained by the kernel with respect to calendar \r
+ time*/\r
+ portNVIC_SYSTICK_CTRL_REG = ( portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT );\r
+\r
+ /* Determine if the SysTick clock has already counted to zero and\r
+ been set back to the current reload value (the reload back being\r
+ correct for the entire expected idle time) or if the SysTick is yet\r
+ to count to zero (in which case an interrupt other than the SysTick\r
+ must have brought the system out of sleep mode). */\r
+ if( ( portNVIC_SYSTICK_CTRL_REG & portNVIC_SYSTICK_COUNT_FLAG_BIT ) != 0 )\r
{\r
uint32_t ulCalculatedLoadValue;\r
\r
- /* The tick interrupt has already executed, and the SysTick\r
- count reloaded with ulReloadValue. Reset the\r
+ /* The tick interrupt is already pending, and the SysTick count\r
+ reloaded with ulReloadValue. Reset the\r
portNVIC_SYSTICK_LOAD_REG with whatever remains of this tick\r
period. */\r
ulCalculatedLoadValue = ( ulTimerCountsForOneTick - 1UL ) - ( ulReloadValue - portNVIC_SYSTICK_CURRENT_VALUE_REG );\r
\r
portNVIC_SYSTICK_LOAD_REG = ulCalculatedLoadValue;\r
\r
- /* The tick interrupt handler will already have pended the tick\r
- processing in the kernel. As the pending tick will be\r
- processed as soon as this function exits, the tick value\r
- maintained by the tick is stepped forward by one less than the\r
- time spent waiting. */\r
+ /* As the pending tick will be processed as soon as this\r
+ function exits, the tick value maintained by the tick is stepped\r
+ forward by one less than the time spent waiting. */\r
ulCompleteTickPeriods = xExpectedIdleTime - 1UL;\r
}\r
else\r
\r
/* Restart SysTick so it runs from portNVIC_SYSTICK_LOAD_REG\r
again, then set portNVIC_SYSTICK_LOAD_REG back to its standard\r
- value. The critical section is used to ensure the tick interrupt\r
- can only execute once in the case that the reload register is near\r
- zero. */\r
+ value. */\r
portNVIC_SYSTICK_CURRENT_VALUE_REG = 0UL;\r
- portENTER_CRITICAL();\r
- {\r
- portNVIC_SYSTICK_CTRL_REG |= portNVIC_SYSTICK_ENABLE_BIT;\r
- vTaskStepTick( ulCompleteTickPeriods );\r
- portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;\r
- }\r
- portEXIT_CRITICAL();\r
+ portNVIC_SYSTICK_CTRL_REG |= portNVIC_SYSTICK_ENABLE_BIT;\r
+ vTaskStepTick( ulCompleteTickPeriods );\r
+ portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;\r
+\r
+ /* Exit with interrpts enabled. */\r
+ __enable_interrupt();\r
}\r
}\r
\r
-#endif /* #if configUSE_TICKLESS_IDLE */\r
+#endif /* configUSE_TICKLESS_IDLE */\r
/*-----------------------------------------------------------*/\r
\r
/*\r
uint8_t ucCurrentPriority;\r
\r
/* Obtain the number of the currently executing interrupt. */\r
- __asm volatile( "mrs %0, ipsr" : "=r"( ulCurrentInterrupt ) );\r
+ __asm volatile( "mrs %0, ipsr" : "=r"( ulCurrentInterrupt ) :: "memory" );\r
\r
/* Is the interrupt number a user defined interrupt? */\r
if( ulCurrentInterrupt >= portFIRST_USER_INTERRUPT_NUMBER )\r
devices by calling NVIC_SetPriorityGrouping( 0 ); before starting the\r
scheduler. Note however that some vendor specific peripheral libraries\r
assume a non-zero priority group setting, in which cases using a value\r
- of zero will result in unpredicable behaviour. */\r
+ of zero will result in unpredictable behaviour. */\r
configASSERT( ( portAIRCR_REG & portPRIORITY_GROUP_MASK ) <= ulMaxPRIGROUPValue );\r
}\r
\r
*-----------------------------------------------------------\r
*/\r
\r
+/* IAR includes. */\r
+#include <intrinsics.h>\r
+\r
/* Type definitions. */\r
#define portCHAR char\r
#define portFLOAT float\r
#define configUSE_PORT_OPTIMISED_TASK_SELECTION 1\r
#endif\r
\r
-#if configUSE_PORT_OPTIMISED_TASK_SELECTION == 1\r
+#if( configUSE_PORT_OPTIMISED_TASK_SELECTION == 1 )\r
\r
/* Check the configuration. */\r
#if( configMAX_PRIORITIES > 32 )\r
\r
/*-----------------------------------------------------------*/\r
\r
- #include <intrinsics.h>\r
#define portGET_HIGHEST_PRIORITY( uxTopPriority, uxReadyPriorities ) uxTopPriority = ( 31UL - ( ( uint32_t ) __CLZ( ( uxReadyPriorities ) ) ) )\r
\r
#endif /* configUSE_PORT_OPTIMISED_TASK_SELECTION */\r
* Implementation of functions defined in portable.h for the ARM CM4F port.\r
*----------------------------------------------------------*/\r
\r
-/* Compiler includes. */\r
+/* IAR includes. */\r
#include <intrinsics.h>\r
\r
/* Scheduler includes. */\r
#error This port can only be used when the project options are configured to enable hardware floating point support.\r
#endif\r
\r
-#if configMAX_SYSCALL_INTERRUPT_PRIORITY == 0\r
+#if( configMAX_SYSCALL_INTERRUPT_PRIORITY == 0 )\r
#error configMAX_SYSCALL_INTERRUPT_PRIORITY must not be set to 0. See http://www.FreeRTOS.org/RTOS-Cortex-M3-M4.html\r
#endif\r
\r
have bit-0 clear, as it is loaded into the PC on exit from an ISR. */\r
#define portSTART_ADDRESS_MASK ( ( StackType_t ) 0xfffffffeUL )\r
\r
-/* Each task maintains its own interrupt status in the critical nesting\r
-variable. */\r
-static UBaseType_t uxCriticalNesting = 0xaaaaaaaa;\r
-\r
/*\r
* Setup the timer to generate the tick interrupts. The implementation in this\r
* file is weak to allow application writers to change the timer used to\r
\r
/*-----------------------------------------------------------*/\r
\r
+/* Each task maintains its own interrupt status in the critical nesting\r
+variable. */\r
+static UBaseType_t uxCriticalNesting = 0xaaaaaaaa;\r
+\r
/*\r
* The number of SysTick increments that make up one tick period.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t ulTimerCountsForOneTick = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
* The maximum number of tick periods that can be suppressed is limited by the\r
* 24 bit resolution of the SysTick timer.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t xMaximumPossibleSuppressedTicks = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
* Compensate for the CPU cycles that pass while the SysTick is stopped (low\r
* power functionality only.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t ulStoppedTimerCompensation = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
* FreeRTOS API functions are not called from interrupts that have been assigned\r
* a priority above configMAX_SYSCALL_INTERRUPT_PRIORITY.\r
*/\r
-#if ( configASSERT_DEFINED == 1 )\r
+#if( configASSERT_DEFINED == 1 )\r
static uint8_t ucMaxSysCallPriority = 0;\r
static uint32_t ulMaxPRIGROUPValue = 0;\r
static const volatile uint8_t * const pcInterruptPriorityRegisters = ( const volatile uint8_t * const ) portNVIC_IP_REGISTERS_OFFSET_16;\r
}\r
/*-----------------------------------------------------------*/\r
\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
\r
__weak void vPortSuppressTicksAndSleep( TickType_t xExpectedIdleTime )\r
{\r
- uint32_t ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickDecrements, ulSysTickCTRL;\r
+ uint32_t ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickDecrements;\r
TickType_t xModifiableIdleTime;\r
\r
/* Make sure the SysTick reload value does not overflow the counter. */\r
__DSB();\r
__ISB();\r
\r
-\r
/* If a context switch is pending or a task is waiting for the scheduler\r
to be unsuspended then abandon the low power entry. */\r
if( eTaskConfirmSleepModeStatus() == eAbortSleep )\r
}\r
configPOST_SLEEP_PROCESSING( xExpectedIdleTime );\r
\r
- /* Stop SysTick. Again, the time the SysTick is stopped for is\r
- accounted for as best it can be, but using the tickless mode will\r
- inevitably result in some tiny drift of the time maintained by the\r
- kernel with respect to calendar time. */\r
- ulSysTickCTRL = portNVIC_SYSTICK_CTRL_REG;\r
- portNVIC_SYSTICK_CTRL_REG = ( ulSysTickCTRL & ~portNVIC_SYSTICK_ENABLE_BIT );\r
-\r
- /* Re-enable interrupts - see comments above __disable_interrupt()\r
- call above. */\r
+ /* Re-enable interrupts to allow the interrupt that brought the MCU\r
+ out of sleep mode to execute immediately. see comments above\r
+ __disable_interrupt() call above. */\r
__enable_interrupt();\r
-\r
- if( ( ulSysTickCTRL & portNVIC_SYSTICK_COUNT_FLAG_BIT ) != 0 )\r
+ __DSB();\r
+ __ISB();\r
+\r
+ /* Disable interrupts again because the clock is about to be stopped\r
+ and interrupts that execute while the clock is stopped will increase\r
+ any slippage between the time maintained by the RTOS and calendar\r
+ time. */\r
+ __disable_interrupt();\r
+ __DSB();\r
+ __ISB();\r
+ \r
+ /* Disable the SysTick clock without reading the \r
+ portNVIC_SYSTICK_CTRL_REG register to ensure the\r
+ portNVIC_SYSTICK_COUNT_FLAG_BIT is not cleared if it is set. Again, \r
+ the time the SysTick is stopped for is accounted for as best it can \r
+ be, but using the tickless mode will inevitably result in some tiny \r
+ drift of the time maintained by the kernel with respect to calendar \r
+ time*/\r
+ portNVIC_SYSTICK_CTRL_REG = ( portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT );\r
+\r
+ /* Determine if the SysTick clock has already counted to zero and\r
+ been set back to the current reload value (the reload back being\r
+ correct for the entire expected idle time) or if the SysTick is yet\r
+ to count to zero (in which case an interrupt other than the SysTick\r
+ must have brought the system out of sleep mode). */\r
+ if( ( portNVIC_SYSTICK_CTRL_REG & portNVIC_SYSTICK_COUNT_FLAG_BIT ) != 0 )\r
{\r
uint32_t ulCalculatedLoadValue;\r
\r
- /* The tick interrupt has already executed, and the SysTick\r
- count reloaded with ulReloadValue. Reset the\r
+ /* The tick interrupt is already pending, and the SysTick count\r
+ reloaded with ulReloadValue. Reset the\r
portNVIC_SYSTICK_LOAD_REG with whatever remains of this tick\r
period. */\r
ulCalculatedLoadValue = ( ulTimerCountsForOneTick - 1UL ) - ( ulReloadValue - portNVIC_SYSTICK_CURRENT_VALUE_REG );\r
\r
portNVIC_SYSTICK_LOAD_REG = ulCalculatedLoadValue;\r
\r
- /* The tick interrupt handler will already have pended the tick\r
- processing in the kernel. As the pending tick will be\r
- processed as soon as this function exits, the tick value\r
- maintained by the tick is stepped forward by one less than the\r
- time spent waiting. */\r
+ /* As the pending tick will be processed as soon as this\r
+ function exits, the tick value maintained by the tick is stepped\r
+ forward by one less than the time spent waiting. */\r
ulCompleteTickPeriods = xExpectedIdleTime - 1UL;\r
}\r
else\r
\r
/* Restart SysTick so it runs from portNVIC_SYSTICK_LOAD_REG\r
again, then set portNVIC_SYSTICK_LOAD_REG back to its standard\r
- value. The critical section is used to ensure the tick interrupt\r
- can only execute once in the case that the reload register is near\r
- zero. */\r
+ value. */\r
portNVIC_SYSTICK_CURRENT_VALUE_REG = 0UL;\r
- portENTER_CRITICAL();\r
- {\r
- portNVIC_SYSTICK_CTRL_REG |= portNVIC_SYSTICK_ENABLE_BIT;\r
- vTaskStepTick( ulCompleteTickPeriods );\r
- portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;\r
- }\r
- portEXIT_CRITICAL();\r
+ portNVIC_SYSTICK_CTRL_REG |= portNVIC_SYSTICK_ENABLE_BIT;\r
+ vTaskStepTick( ulCompleteTickPeriods );\r
+ portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;\r
+\r
+ /* Exit with interrpts enabled. */\r
+ __enable_interrupt();\r
}\r
}\r
\r
-#endif /* #if configUSE_TICKLESS_IDLE */\r
+#endif /* configUSE_TICKLESS_IDLE */\r
/*-----------------------------------------------------------*/\r
\r
/*\r
uint8_t ucCurrentPriority;\r
\r
/* Obtain the number of the currently executing interrupt. */\r
- __asm volatile( "mrs %0, ipsr" : "=r"( ulCurrentInterrupt ) );\r
+ __asm volatile( "mrs %0, ipsr" : "=r"( ulCurrentInterrupt ) :: "memory" );\r
\r
/* Is the interrupt number a user defined interrupt? */\r
if( ulCurrentInterrupt >= portFIRST_USER_INTERRUPT_NUMBER )\r
devices by calling NVIC_SetPriorityGrouping( 0 ); before starting the\r
scheduler. Note however that some vendor specific peripheral libraries\r
assume a non-zero priority group setting, in which cases using a value\r
- of zero will result in unpredicable behaviour. */\r
+ of zero will result in unpredictable behaviour. */\r
configASSERT( ( portAIRCR_REG & portPRIORITY_GROUP_MASK ) <= ulMaxPRIGROUPValue );\r
}\r
\r
*-----------------------------------------------------------\r
*/\r
\r
+/* IAR includes. */\r
+#include <intrinsics.h>\r
+\r
/* Type definitions. */\r
#define portCHAR char\r
#define portFLOAT float\r
#define configUSE_PORT_OPTIMISED_TASK_SELECTION 1\r
#endif\r
\r
-#if configUSE_PORT_OPTIMISED_TASK_SELECTION == 1\r
+#if( configUSE_PORT_OPTIMISED_TASK_SELECTION == 1 )\r
\r
/* Check the configuration. */\r
#if( configMAX_PRIORITIES > 32 )\r
\r
/*-----------------------------------------------------------*/\r
\r
- #include <intrinsics.h>\r
#define portGET_HIGHEST_PRIORITY( uxTopPriority, uxReadyPriorities ) uxTopPriority = ( 31UL - ( ( uint32_t ) __CLZ( ( uxReadyPriorities ) ) ) )\r
\r
#endif /* configUSE_PORT_OPTIMISED_TASK_SELECTION */\r
* Implementation of functions defined in portable.h for the ARM CM4F port.\r
*----------------------------------------------------------*/\r
\r
-/* Compiler includes. */\r
+/* IAR includes. */\r
#include <intrinsics.h>\r
\r
/* Scheduler includes. */\r
#error This port can only be used when the project options are configured to enable hardware floating point support.\r
#endif\r
\r
-#if configMAX_SYSCALL_INTERRUPT_PRIORITY == 0\r
+#if( configMAX_SYSCALL_INTERRUPT_PRIORITY == 0 )\r
#error configMAX_SYSCALL_INTERRUPT_PRIORITY must not be set to 0. See http://www.FreeRTOS.org/RTOS-Cortex-M3-M4.html\r
#endif\r
\r
have bit-0 clear, as it is loaded into the PC on exit from an ISR. */\r
#define portSTART_ADDRESS_MASK ( ( StackType_t ) 0xfffffffeUL )\r
\r
-/* Each task maintains its own interrupt status in the critical nesting\r
-variable. */\r
-static UBaseType_t uxCriticalNesting = 0xaaaaaaaa;\r
-\r
/*\r
* Setup the timer to generate the tick interrupts. The implementation in this\r
* file is weak to allow application writers to change the timer used to\r
\r
/*-----------------------------------------------------------*/\r
\r
+/* Each task maintains its own interrupt status in the critical nesting\r
+variable. */\r
+static UBaseType_t uxCriticalNesting = 0xaaaaaaaa;\r
+\r
/*\r
* The number of SysTick increments that make up one tick period.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t ulTimerCountsForOneTick = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
* The maximum number of tick periods that can be suppressed is limited by the\r
* 24 bit resolution of the SysTick timer.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t xMaximumPossibleSuppressedTicks = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
* Compensate for the CPU cycles that pass while the SysTick is stopped (low\r
* power functionality only.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t ulStoppedTimerCompensation = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
* FreeRTOS API functions are not called from interrupts that have been assigned\r
* a priority above configMAX_SYSCALL_INTERRUPT_PRIORITY.\r
*/\r
-#if ( configASSERT_DEFINED == 1 )\r
+#if( configASSERT_DEFINED == 1 )\r
static uint8_t ucMaxSysCallPriority = 0;\r
static uint32_t ulMaxPRIGROUPValue = 0;\r
static const volatile uint8_t * const pcInterruptPriorityRegisters = ( const volatile uint8_t * const ) portNVIC_IP_REGISTERS_OFFSET_16;\r
*/\r
BaseType_t xPortStartScheduler( void )\r
{\r
+ /* configMAX_SYSCALL_INTERRUPT_PRIORITY must not be set to 0.\r
+ See http://www.FreeRTOS.org/RTOS-Cortex-M3-M4.html */\r
+ configASSERT( configMAX_SYSCALL_INTERRUPT_PRIORITY );\r
+\r
#if( configASSERT_DEFINED == 1 )\r
{\r
volatile uint32_t ulOriginalPriority;\r
}\r
/*-----------------------------------------------------------*/\r
\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
\r
__weak void vPortSuppressTicksAndSleep( TickType_t xExpectedIdleTime )\r
{\r
- uint32_t ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickDecrements, ulSysTickCTRL;\r
+ uint32_t ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickDecrements;\r
TickType_t xModifiableIdleTime;\r
\r
/* Make sure the SysTick reload value does not overflow the counter. */\r
}\r
configPOST_SLEEP_PROCESSING( xExpectedIdleTime );\r
\r
- /* Stop SysTick. Again, the time the SysTick is stopped for is\r
- accounted for as best it can be, but using the tickless mode will\r
- inevitably result in some tiny drift of the time maintained by the\r
- kernel with respect to calendar time. */\r
- ulSysTickCTRL = portNVIC_SYSTICK_CTRL_REG;\r
- portNVIC_SYSTICK_CTRL_REG = ( ulSysTickCTRL & ~portNVIC_SYSTICK_ENABLE_BIT );\r
-\r
- /* Re-enable interrupts - see comments above __disable_interrupt()\r
- call above. */\r
+ /* Re-enable interrupts to allow the interrupt that brought the MCU\r
+ out of sleep mode to execute immediately. see comments above\r
+ __disable_interrupt() call above. */\r
__enable_interrupt();\r
-\r
- if( ( ulSysTickCTRL & portNVIC_SYSTICK_COUNT_FLAG_BIT ) != 0 )\r
+ __DSB();\r
+ __ISB();\r
+\r
+ /* Disable interrupts again because the clock is about to be stopped\r
+ and interrupts that execute while the clock is stopped will increase\r
+ any slippage between the time maintained by the RTOS and calendar\r
+ time. */\r
+ __disable_interrupt();\r
+ __DSB();\r
+ __ISB();\r
+ \r
+ /* Disable the SysTick clock without reading the \r
+ portNVIC_SYSTICK_CTRL_REG register to ensure the\r
+ portNVIC_SYSTICK_COUNT_FLAG_BIT is not cleared if it is set. Again, \r
+ the time the SysTick is stopped for is accounted for as best it can \r
+ be, but using the tickless mode will inevitably result in some tiny \r
+ drift of the time maintained by the kernel with respect to calendar \r
+ time*/\r
+ portNVIC_SYSTICK_CTRL_REG = ( portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT );\r
+\r
+ /* Determine if the SysTick clock has already counted to zero and\r
+ been set back to the current reload value (the reload back being\r
+ correct for the entire expected idle time) or if the SysTick is yet\r
+ to count to zero (in which case an interrupt other than the SysTick\r
+ must have brought the system out of sleep mode). */\r
+ if( ( portNVIC_SYSTICK_CTRL_REG & portNVIC_SYSTICK_COUNT_FLAG_BIT ) != 0 )\r
{\r
uint32_t ulCalculatedLoadValue;\r
\r
- /* The tick interrupt has already executed, and the SysTick\r
- count reloaded with ulReloadValue. Reset the\r
+ /* The tick interrupt is already pending, and the SysTick count\r
+ reloaded with ulReloadValue. Reset the\r
portNVIC_SYSTICK_LOAD_REG with whatever remains of this tick\r
period. */\r
ulCalculatedLoadValue = ( ulTimerCountsForOneTick - 1UL ) - ( ulReloadValue - portNVIC_SYSTICK_CURRENT_VALUE_REG );\r
\r
portNVIC_SYSTICK_LOAD_REG = ulCalculatedLoadValue;\r
\r
- /* The tick interrupt handler will already have pended the tick\r
- processing in the kernel. As the pending tick will be\r
- processed as soon as this function exits, the tick value\r
- maintained by the tick is stepped forward by one less than the\r
- time spent waiting. */\r
+ /* As the pending tick will be processed as soon as this\r
+ function exits, the tick value maintained by the tick is stepped\r
+ forward by one less than the time spent waiting. */\r
ulCompleteTickPeriods = xExpectedIdleTime - 1UL;\r
}\r
else\r
\r
/* Restart SysTick so it runs from portNVIC_SYSTICK_LOAD_REG\r
again, then set portNVIC_SYSTICK_LOAD_REG back to its standard\r
- value. The critical section is used to ensure the tick interrupt\r
- can only execute once in the case that the reload register is near\r
- zero. */\r
+ value. */\r
portNVIC_SYSTICK_CURRENT_VALUE_REG = 0UL;\r
- portENTER_CRITICAL();\r
- {\r
- portNVIC_SYSTICK_CTRL_REG |= portNVIC_SYSTICK_ENABLE_BIT;\r
- vTaskStepTick( ulCompleteTickPeriods );\r
- portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;\r
- }\r
- portEXIT_CRITICAL();\r
+ portNVIC_SYSTICK_CTRL_REG |= portNVIC_SYSTICK_ENABLE_BIT;\r
+ vTaskStepTick( ulCompleteTickPeriods );\r
+ portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;\r
+\r
+ /* Exit with interrpts enabled. */\r
+ __enable_interrupt();\r
}\r
}\r
\r
-#endif /* #if configUSE_TICKLESS_IDLE */\r
+#endif /* configUSE_TICKLESS_IDLE */\r
/*-----------------------------------------------------------*/\r
\r
/*\r
uint8_t ucCurrentPriority;\r
\r
/* Obtain the number of the currently executing interrupt. */\r
- __asm volatile( "mrs %0, ipsr" : "=r"( ulCurrentInterrupt ) );\r
+ __asm volatile( "mrs %0, ipsr" : "=r"( ulCurrentInterrupt ) :: "memory" );\r
\r
/* Is the interrupt number a user defined interrupt? */\r
if( ulCurrentInterrupt >= portFIRST_USER_INTERRUPT_NUMBER )\r
devices by calling NVIC_SetPriorityGrouping( 0 ); before starting the\r
scheduler. Note however that some vendor specific peripheral libraries\r
assume a non-zero priority group setting, in which cases using a value\r
- of zero will result in unpredicable behaviour. */\r
+ of zero will result in unpredictable behaviour. */\r
configASSERT( ( portAIRCR_REG & portPRIORITY_GROUP_MASK ) <= ulMaxPRIGROUPValue );\r
}\r
\r
*-----------------------------------------------------------\r
*/\r
\r
+/* IAR includes. */\r
+#include <intrinsics.h>\r
+\r
/* Type definitions. */\r
#define portCHAR char\r
#define portFLOAT float\r
#define configUSE_PORT_OPTIMISED_TASK_SELECTION 1\r
#endif\r
\r
-#if configUSE_PORT_OPTIMISED_TASK_SELECTION == 1\r
+#if( configUSE_PORT_OPTIMISED_TASK_SELECTION == 1 )\r
\r
/* Check the configuration. */\r
#if( configMAX_PRIORITIES > 32 )\r
\r
/*-----------------------------------------------------------*/\r
\r
- #include <intrinsics.h>\r
#define portGET_HIGHEST_PRIORITY( uxTopPriority, uxReadyPriorities ) uxTopPriority = ( 31UL - ( ( uint32_t ) __CLZ( ( uxReadyPriorities ) ) ) )\r
\r
#endif /* configUSE_PORT_OPTIMISED_TASK_SELECTION */\r
/*\r
* The number of SysTick increments that make up one tick period.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t ulTimerCountsForOneTick = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
* The maximum number of tick periods that can be suppressed is limited by the\r
* 24 bit resolution of the SysTick timer.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t xMaximumPossibleSuppressedTicks = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
* Compensate for the CPU cycles that pass while the SysTick is stopped (low\r
* power functionality only.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t ulStoppedTimerCompensation = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
\r
void vPortSuppressTicksAndSleep( TickType_t xExpectedIdleTime )\r
{\r
- uint32_t ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickDecrements, ulSysTickCTRL;\r
+ uint32_t ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickDecrements;\r
TickType_t xModifiableIdleTime;\r
\r
/* Make sure the SysTick reload value does not overflow the counter. */\r
}\r
configPOST_SLEEP_PROCESSING( xExpectedIdleTime );\r
\r
- /* Stop SysTick. Again, the time the SysTick is stopped for is\r
- accounted for as best it can be, but using the tickless mode will\r
- inevitably result in some tiny drift of the time maintained by the\r
- kernel with respect to calendar time. */\r
- ulSysTickCTRL = portNVIC_SYSTICK_CTRL_REG;\r
- portNVIC_SYSTICK_CTRL_REG = ( ulSysTickCTRL & ~portNVIC_SYSTICK_ENABLE_BIT );\r
-\r
- /* Re-enable interrupts - see comments above the cpsid instruction()\r
- above. */\r
+ /* Re-enable interrupts to allow the interrupt that brought the MCU\r
+ out of sleep mode to execute immediately. see comments above\r
+ __disable_interrupt() call above. */\r
__asm { "cpsie i" };\r
- __asm { "wfi" };\r
- __asm { "isb" };\r
-\r
- if( ( ulSysTickCTRL & portNVIC_SYSTICK_COUNT_FLAG_BIT ) != 0 )\r
+ __asm { "dsb" };\r
+ __asm { "isb" };\r
+\r
+ /* Disable interrupts again because the clock is about to be stopped\r
+ and interrupts that execute while the clock is stopped will increase\r
+ any slippage between the time maintained by the RTOS and calendar\r
+ time. */\r
+ __asm { "cpsid i" };\r
+ __asm { "dsb" };\r
+ __asm { "isb" };\r
+ \r
+ /* Disable the SysTick clock without reading the \r
+ portNVIC_SYSTICK_CTRL_REG register to ensure the\r
+ portNVIC_SYSTICK_COUNT_FLAG_BIT is not cleared if it is set. Again, \r
+ the time the SysTick is stopped for is accounted for as best it can \r
+ be, but using the tickless mode will inevitably result in some tiny \r
+ drift of the time maintained by the kernel with respect to calendar \r
+ time*/\r
+ portNVIC_SYSTICK_CTRL_REG = ( portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT );\r
+\r
+ /* Determine if the SysTick clock has already counted to zero and\r
+ been set back to the current reload value (the reload back being\r
+ correct for the entire expected idle time) or if the SysTick is yet\r
+ to count to zero (in which case an interrupt other than the SysTick\r
+ must have brought the system out of sleep mode). */\r
+ if( ( portNVIC_SYSTICK_CTRL_REG & portNVIC_SYSTICK_COUNT_FLAG_BIT ) != 0 )\r
{\r
uint32_t ulCalculatedLoadValue;\r
\r
- /* The tick interrupt has already executed, and the SysTick\r
- count reloaded with ulReloadValue. Reset the\r
+ /* The tick interrupt is already pending, and the SysTick count\r
+ reloaded with ulReloadValue. Reset the\r
portNVIC_SYSTICK_LOAD_REG with whatever remains of this tick\r
period. */\r
ulCalculatedLoadValue = ( ulTimerCountsForOneTick - 1UL ) - ( ulReloadValue - portNVIC_SYSTICK_CURRENT_VALUE_REG );\r
\r
portNVIC_SYSTICK_LOAD_REG = ulCalculatedLoadValue;\r
\r
- /* The tick interrupt handler will already have pended the tick\r
- processing in the kernel. As the pending tick will be\r
- processed as soon as this function exits, the tick value\r
- maintained by the tick is stepped forward by one less than the\r
- time spent waiting. */\r
+ /* As the pending tick will be processed as soon as this\r
+ function exits, the tick value maintained by the tick is stepped\r
+ forward by one less than the time spent waiting. */\r
ulCompleteTickPeriods = xExpectedIdleTime - 1UL;\r
}\r
else\r
\r
/* The reload value is set to whatever fraction of a single tick\r
period remains. */\r
- portNVIC_SYSTICK_LOAD_REG = ( ( ulCompleteTickPeriods + 1 ) * ulTimerCountsForOneTick ) - ulCompletedSysTickDecrements;\r
+ portNVIC_SYSTICK_LOAD_REG = ( ( ulCompleteTickPeriods + 1UL ) * ulTimerCountsForOneTick ) - ulCompletedSysTickDecrements;\r
}\r
\r
/* Restart SysTick so it runs from portNVIC_SYSTICK_LOAD_REG\r
again, then set portNVIC_SYSTICK_LOAD_REG back to its standard\r
- value. The critical section is used to ensure the tick interrupt\r
- can only execute once in the case that the reload register is near\r
- zero. */\r
+ value. */\r
portNVIC_SYSTICK_CURRENT_VALUE_REG = 0UL;\r
- portENTER_CRITICAL();\r
- {\r
- portNVIC_SYSTICK_CTRL_REG |= portNVIC_SYSTICK_ENABLE_BIT;\r
- vTaskStepTick( ulCompleteTickPeriods );\r
- portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;\r
- }\r
- portEXIT_CRITICAL();\r
+ portNVIC_SYSTICK_CTRL_REG |= portNVIC_SYSTICK_ENABLE_BIT;\r
+ vTaskStepTick( ulCompleteTickPeriods );\r
+ portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;\r
+\r
+ /* Exit with interrpts enabled. */\r
+ __asm { "cpsie i" };\r
}\r
}\r
\r
void vPortSetupTimerInterrupt( void )\r
{\r
/* Calculate the constants required to configure the tick interrupt. */\r
- #if configUSE_TICKLESS_IDLE == 1\r
+ #if( configUSE_TICKLESS_IDLE == 1 )\r
{\r
ulTimerCountsForOneTick = ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ );\r
xMaximumPossibleSuppressedTicks = portMAX_24_BIT_NUMBER / ulTimerCountsForOneTick;\r
devices by calling NVIC_SetPriorityGrouping( 0 ); before starting the\r
scheduler. Note however that some vendor specific peripheral libraries\r
assume a non-zero priority group setting, in which cases using a value\r
- of zero will result in unpredicable behaviour. */\r
+ of zero will result in unpredictable behaviour. */\r
configASSERT( ( portAIRCR_REG & portPRIORITY_GROUP_MASK ) <= ulMaxPRIGROUPValue );\r
}\r
\r
#define portNVIC_PENDSVCLEAR_BIT ( 1UL << 27UL )\r
#define portNVIC_PEND_SYSTICK_CLEAR_BIT ( 1UL << 25UL )\r
\r
-/* Masks off all bits but the VECTACTIVE bits in the ICSR register. */\r
-#define portVECTACTIVE_MASK ( 0xFFUL )\r
-\r
#define portNVIC_PENDSV_PRI ( ( ( uint32_t ) configKERNEL_INTERRUPT_PRIORITY ) << 16UL )\r
#define portNVIC_SYSTICK_PRI ( ( ( uint32_t ) configKERNEL_INTERRUPT_PRIORITY ) << 24UL )\r
\r
#define portPRIORITY_GROUP_MASK ( 0x07UL << 8UL )\r
#define portPRIGROUP_SHIFT ( 8UL )\r
\r
+/* Masks off all bits but the VECTACTIVE bits in the ICSR register. */\r
+#define portVECTACTIVE_MASK ( 0xFFUL )\r
+\r
/* Constants required to set up the initial stack. */\r
#define portINITIAL_XPSR ( 0x01000000 )\r
\r
have bit-0 clear, as it is loaded into the PC on exit from an ISR. */\r
#define portSTART_ADDRESS_MASK ( ( StackType_t ) 0xfffffffeUL )\r
\r
-/* Each task maintains its own interrupt status in the critical nesting\r
-variable. */\r
-static UBaseType_t uxCriticalNesting = 0xaaaaaaaa;\r
-\r
/*\r
* Setup the timer to generate the tick interrupts. The implementation in this\r
* file is weak to allow application writers to change the timer used to\r
\r
/*-----------------------------------------------------------*/\r
\r
+/* Each task maintains its own interrupt status in the critical nesting\r
+variable. */\r
+static UBaseType_t uxCriticalNesting = 0xaaaaaaaa;\r
+\r
/*\r
* The number of SysTick increments that make up one tick period.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t ulTimerCountsForOneTick = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
* The maximum number of tick periods that can be suppressed is limited by the\r
* 24 bit resolution of the SysTick timer.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t xMaximumPossibleSuppressedTicks = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
* Compensate for the CPU cycles that pass while the SysTick is stopped (low\r
* power functionality only.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t ulStoppedTimerCompensation = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
/* Read the value back to see how many bits stuck. */\r
ucMaxPriorityValue = *pucFirstUserPriorityRegister;\r
\r
+ /* The kernel interrupt priority should be set to the lowest\r
+ priority. */\r
+ configASSERT( ucMaxPriorityValue == ( configKERNEL_INTERRUPT_PRIORITY & ucMaxPriorityValue ) );\r
+\r
/* Use the same mask on the maximum system call priority. */\r
ucMaxSysCallPriority = configMAX_SYSCALL_INTERRUPT_PRIORITY & ucMaxPriorityValue;\r
\r
}\r
/*-----------------------------------------------------------*/\r
\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
\r
__weak void vPortSuppressTicksAndSleep( TickType_t xExpectedIdleTime )\r
{\r
- uint32_t ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickDecrements, ulSysTickCTRL;\r
+ uint32_t ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickDecrements;\r
TickType_t xModifiableIdleTime;\r
\r
/* Make sure the SysTick reload value does not overflow the counter. */\r
}\r
configPOST_SLEEP_PROCESSING( xExpectedIdleTime );\r
\r
- /* Stop SysTick. Again, the time the SysTick is stopped for is\r
- accounted for as best it can be, but using the tickless mode will\r
- inevitably result in some tiny drift of the time maintained by the\r
- kernel with respect to calendar time. */\r
- ulSysTickCTRL = portNVIC_SYSTICK_CTRL_REG;\r
- portNVIC_SYSTICK_CTRL_REG = ( ulSysTickCTRL & ~portNVIC_SYSTICK_ENABLE_BIT );\r
-\r
- /* Re-enable interrupts - see comments above __disable_irq() call\r
- above. */\r
+ /* Re-enable interrupts to allow the interrupt that brought the MCU\r
+ out of sleep mode to execute immediately. see comments above\r
+ __disable_interrupt() call above. */\r
__enable_irq();\r
-\r
- if( ( ulSysTickCTRL & portNVIC_SYSTICK_COUNT_FLAG_BIT ) != 0 )\r
+ __dsb( portSY_FULL_READ_WRITE );\r
+ __isb( portSY_FULL_READ_WRITE );\r
+\r
+ /* Disable interrupts again because the clock is about to be stopped\r
+ and interrupts that execute while the clock is stopped will increase\r
+ any slippage between the time maintained by the RTOS and calendar\r
+ time. */\r
+ __disable_irq();\r
+ __dsb( portSY_FULL_READ_WRITE );\r
+ __isb( portSY_FULL_READ_WRITE );\r
+ \r
+ /* Disable the SysTick clock without reading the \r
+ portNVIC_SYSTICK_CTRL_REG register to ensure the\r
+ portNVIC_SYSTICK_COUNT_FLAG_BIT is not cleared if it is set. Again, \r
+ the time the SysTick is stopped for is accounted for as best it can \r
+ be, but using the tickless mode will inevitably result in some tiny \r
+ drift of the time maintained by the kernel with respect to calendar \r
+ time*/\r
+ portNVIC_SYSTICK_CTRL_REG = ( portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT );\r
+\r
+ /* Determine if the SysTick clock has already counted to zero and\r
+ been set back to the current reload value (the reload back being\r
+ correct for the entire expected idle time) or if the SysTick is yet\r
+ to count to zero (in which case an interrupt other than the SysTick\r
+ must have brought the system out of sleep mode). */\r
+ if( ( portNVIC_SYSTICK_CTRL_REG & portNVIC_SYSTICK_COUNT_FLAG_BIT ) != 0 )\r
{\r
uint32_t ulCalculatedLoadValue;\r
\r
- /* The tick interrupt has already executed, and the SysTick\r
- count reloaded with ulReloadValue. Reset the\r
+ /* The tick interrupt is already pending, and the SysTick count\r
+ reloaded with ulReloadValue. Reset the\r
portNVIC_SYSTICK_LOAD_REG with whatever remains of this tick\r
period. */\r
ulCalculatedLoadValue = ( ulTimerCountsForOneTick - 1UL ) - ( ulReloadValue - portNVIC_SYSTICK_CURRENT_VALUE_REG );\r
\r
portNVIC_SYSTICK_LOAD_REG = ulCalculatedLoadValue;\r
\r
- /* The tick interrupt handler will already have pended the tick\r
- processing in the kernel. As the pending tick will be\r
- processed as soon as this function exits, the tick value\r
- maintained by the tick is stepped forward by one less than the\r
- time spent waiting. */\r
+ /* As the pending tick will be processed as soon as this\r
+ function exits, the tick value maintained by the tick is stepped\r
+ forward by one less than the time spent waiting. */\r
ulCompleteTickPeriods = xExpectedIdleTime - 1UL;\r
}\r
else\r
\r
/* Restart SysTick so it runs from portNVIC_SYSTICK_LOAD_REG\r
again, then set portNVIC_SYSTICK_LOAD_REG back to its standard\r
- value. The critical section is used to ensure the tick interrupt\r
- can only execute once in the case that the reload register is near\r
- zero. */\r
+ value. */\r
portNVIC_SYSTICK_CURRENT_VALUE_REG = 0UL;\r
- portENTER_CRITICAL();\r
- {\r
- portNVIC_SYSTICK_CTRL_REG |= portNVIC_SYSTICK_ENABLE_BIT;\r
- vTaskStepTick( ulCompleteTickPeriods );\r
- portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;\r
- }\r
- portEXIT_CRITICAL();\r
+ portNVIC_SYSTICK_CTRL_REG |= portNVIC_SYSTICK_ENABLE_BIT;\r
+ vTaskStepTick( ulCompleteTickPeriods );\r
+ portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;\r
+\r
+ /* Exit with interrpts enabled. */\r
+ __enable_irq();\r
}\r
}\r
\r
* Setup the SysTick timer to generate the tick interrupts at the required\r
* frequency.\r
*/\r
-#if configOVERRIDE_DEFAULT_TICK_CONFIGURATION == 0\r
+#if( configOVERRIDE_DEFAULT_TICK_CONFIGURATION == 0 )\r
\r
void vPortSetupTimerInterrupt( void )\r
{\r
/* Calculate the constants required to configure the tick interrupt. */\r
- #if configUSE_TICKLESS_IDLE == 1\r
+ #if( configUSE_TICKLESS_IDLE == 1 )\r
{\r
ulTimerCountsForOneTick = ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ );\r
xMaximumPossibleSuppressedTicks = portMAX_24_BIT_NUMBER / ulTimerCountsForOneTick;\r
devices by calling NVIC_SetPriorityGrouping( 0 ); before starting the\r
scheduler. Note however that some vendor specific peripheral libraries\r
assume a non-zero priority group setting, in which cases using a value\r
- of zero will result in unpredicable behaviour. */\r
+ of zero will result in unpredictable behaviour. */\r
configASSERT( ( portAIRCR_REG & portPRIORITY_GROUP_MASK ) <= ulMaxPRIGROUPValue );\r
}\r
\r
have bit-0 clear, as it is loaded into the PC on exit from an ISR. */\r
#define portSTART_ADDRESS_MASK ( ( StackType_t ) 0xfffffffeUL )\r
\r
-/* Each task maintains its own interrupt status in the critical nesting\r
-variable. */\r
-static UBaseType_t uxCriticalNesting = 0xaaaaaaaa;\r
-\r
/*\r
* Setup the timer to generate the tick interrupts. The implementation in this\r
* file is weak to allow application writers to change the timer used to\r
\r
/*-----------------------------------------------------------*/\r
\r
+/* Each task maintains its own interrupt status in the critical nesting\r
+variable. */\r
+static UBaseType_t uxCriticalNesting = 0xaaaaaaaa;\r
+\r
/*\r
* The number of SysTick increments that make up one tick period.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t ulTimerCountsForOneTick = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
* The maximum number of tick periods that can be suppressed is limited by the\r
* 24 bit resolution of the SysTick timer.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t xMaximumPossibleSuppressedTicks = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
* Compensate for the CPU cycles that pass while the SysTick is stopped (low\r
* power functionality only.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t ulStoppedTimerCompensation = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
}\r
/*-----------------------------------------------------------*/\r
\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
\r
__weak void vPortSuppressTicksAndSleep( TickType_t xExpectedIdleTime )\r
{\r
- uint32_t ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickDecrements, ulSysTickCTRL;\r
+ uint32_t ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickDecrements;\r
TickType_t xModifiableIdleTime;\r
\r
/* Make sure the SysTick reload value does not overflow the counter. */\r
}\r
configPOST_SLEEP_PROCESSING( xExpectedIdleTime );\r
\r
- /* Stop SysTick. Again, the time the SysTick is stopped for is\r
- accounted for as best it can be, but using the tickless mode will\r
- inevitably result in some tiny drift of the time maintained by the\r
- kernel with respect to calendar time. */\r
- ulSysTickCTRL = portNVIC_SYSTICK_CTRL_REG;\r
- portNVIC_SYSTICK_CTRL_REG = ( ulSysTickCTRL & ~portNVIC_SYSTICK_ENABLE_BIT );\r
-\r
- /* Re-enable interrupts - see comments above __disable_irq() call\r
- above. */\r
+ /* Re-enable interrupts to allow the interrupt that brought the MCU\r
+ out of sleep mode to execute immediately. see comments above\r
+ __disable_interrupt() call above. */\r
__enable_irq();\r
-\r
- if( ( ulSysTickCTRL & portNVIC_SYSTICK_COUNT_FLAG_BIT ) != 0 )\r
+ __dsb( portSY_FULL_READ_WRITE );\r
+ __isb( portSY_FULL_READ_WRITE );\r
+\r
+ /* Disable interrupts again because the clock is about to be stopped\r
+ and interrupts that execute while the clock is stopped will increase\r
+ any slippage between the time maintained by the RTOS and calendar\r
+ time. */\r
+ __disable_irq();\r
+ __dsb( portSY_FULL_READ_WRITE );\r
+ __isb( portSY_FULL_READ_WRITE );\r
+ \r
+ /* Disable the SysTick clock without reading the \r
+ portNVIC_SYSTICK_CTRL_REG register to ensure the\r
+ portNVIC_SYSTICK_COUNT_FLAG_BIT is not cleared if it is set. Again, \r
+ the time the SysTick is stopped for is accounted for as best it can \r
+ be, but using the tickless mode will inevitably result in some tiny \r
+ drift of the time maintained by the kernel with respect to calendar \r
+ time*/\r
+ portNVIC_SYSTICK_CTRL_REG = ( portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT );\r
+\r
+ /* Determine if the SysTick clock has already counted to zero and\r
+ been set back to the current reload value (the reload back being\r
+ correct for the entire expected idle time) or if the SysTick is yet\r
+ to count to zero (in which case an interrupt other than the SysTick\r
+ must have brought the system out of sleep mode). */\r
+ if( ( portNVIC_SYSTICK_CTRL_REG & portNVIC_SYSTICK_COUNT_FLAG_BIT ) != 0 )\r
{\r
uint32_t ulCalculatedLoadValue;\r
\r
- /* The tick interrupt has already executed, and the SysTick\r
- count reloaded with ulReloadValue. Reset the\r
+ /* The tick interrupt is already pending, and the SysTick count\r
+ reloaded with ulReloadValue. Reset the\r
portNVIC_SYSTICK_LOAD_REG with whatever remains of this tick\r
period. */\r
ulCalculatedLoadValue = ( ulTimerCountsForOneTick - 1UL ) - ( ulReloadValue - portNVIC_SYSTICK_CURRENT_VALUE_REG );\r
\r
portNVIC_SYSTICK_LOAD_REG = ulCalculatedLoadValue;\r
\r
- /* The tick interrupt handler will already have pended the tick\r
- processing in the kernel. As the pending tick will be\r
- processed as soon as this function exits, the tick value\r
- maintained by the tick is stepped forward by one less than the\r
- time spent waiting. */\r
+ /* As the pending tick will be processed as soon as this\r
+ function exits, the tick value maintained by the tick is stepped\r
+ forward by one less than the time spent waiting. */\r
ulCompleteTickPeriods = xExpectedIdleTime - 1UL;\r
}\r
else\r
\r
/* Restart SysTick so it runs from portNVIC_SYSTICK_LOAD_REG\r
again, then set portNVIC_SYSTICK_LOAD_REG back to its standard\r
- value. The critical section is used to ensure the tick interrupt\r
- can only execute once in the case that the reload register is near\r
- zero. */\r
+ value. */\r
portNVIC_SYSTICK_CURRENT_VALUE_REG = 0UL;\r
- portENTER_CRITICAL();\r
- {\r
- portNVIC_SYSTICK_CTRL_REG |= portNVIC_SYSTICK_ENABLE_BIT;\r
- vTaskStepTick( ulCompleteTickPeriods );\r
- portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;\r
- }\r
- portEXIT_CRITICAL();\r
+ portNVIC_SYSTICK_CTRL_REG |= portNVIC_SYSTICK_ENABLE_BIT;\r
+ vTaskStepTick( ulCompleteTickPeriods );\r
+ portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;\r
+\r
+ /* Exit with interrpts enabled. */\r
+ __enable_irq();\r
}\r
}\r
\r
void vPortSetupTimerInterrupt( void )\r
{\r
/* Calculate the constants required to configure the tick interrupt. */\r
- #if configUSE_TICKLESS_IDLE == 1\r
+ #if( configUSE_TICKLESS_IDLE == 1 )\r
{\r
ulTimerCountsForOneTick = ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ );\r
xMaximumPossibleSuppressedTicks = portMAX_24_BIT_NUMBER / ulTimerCountsForOneTick;\r
devices by calling NVIC_SetPriorityGrouping( 0 ); before starting the\r
scheduler. Note however that some vendor specific peripheral libraries\r
assume a non-zero priority group setting, in which cases using a value\r
- of zero will result in unpredicable behaviour. */\r
+ of zero will result in unpredictable behaviour. */\r
configASSERT( ( portAIRCR_REG & portPRIORITY_GROUP_MASK ) <= ulMaxPRIGROUPValue );\r
}\r
\r
#define portINITIAL_EXEC_RETURN ( 0xfffffffd )\r
\r
/* The systick is a 24-bit counter. */\r
-#define portMAX_24_BIT_NUMBER ( 0xffffffUL )\r
+#define portMAX_24_BIT_NUMBER ( 0xffffffUL )\r
\r
/* A fiddle factor to estimate the number of SysTick counts that would have\r
occurred while the SysTick counter is stopped during tickless idle\r
calculations. */\r
-#define portMISSED_COUNTS_FACTOR ( 45UL )\r
+#define portMISSED_COUNTS_FACTOR ( 45UL )\r
\r
/* For strict compliance with the Cortex-M spec the task start address should\r
have bit-0 clear, as it is loaded into the PC on exit from an ISR. */\r
-#define portSTART_ADDRESS_MASK ( ( StackType_t ) 0xfffffffeUL )\r
-\r
-/* Each task maintains its own interrupt status in the critical nesting\r
-variable. */\r
-static UBaseType_t uxCriticalNesting = 0xaaaaaaaa;\r
+#define portSTART_ADDRESS_MASK ( ( StackType_t ) 0xfffffffeUL )\r
\r
/*\r
* Setup the timer to generate the tick interrupts. The implementation in this\r
\r
/*-----------------------------------------------------------*/\r
\r
+/* Each task maintains its own interrupt status in the critical nesting\r
+variable. */\r
+static UBaseType_t uxCriticalNesting = 0xaaaaaaaa;\r
+\r
/*\r
* The number of SysTick increments that make up one tick period.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t ulTimerCountsForOneTick = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
* The maximum number of tick periods that can be suppressed is limited by the\r
* 24 bit resolution of the SysTick timer.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t xMaximumPossibleSuppressedTicks = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
* Compensate for the CPU cycles that pass while the SysTick is stopped (low\r
* power functionality only.\r
*/\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
static uint32_t ulStoppedTimerCompensation = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
}\r
/*-----------------------------------------------------------*/\r
\r
-#if configUSE_TICKLESS_IDLE == 1\r
+#if( configUSE_TICKLESS_IDLE == 1 )\r
\r
__weak void vPortSuppressTicksAndSleep( TickType_t xExpectedIdleTime )\r
{\r
- uint32_t ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickDecrements, ulSysTickCTRL;\r
+ uint32_t ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickDecrements;\r
TickType_t xModifiableIdleTime;\r
\r
/* Make sure the SysTick reload value does not overflow the counter. */\r
}\r
configPOST_SLEEP_PROCESSING( xExpectedIdleTime );\r
\r
- /* Stop SysTick. Again, the time the SysTick is stopped for is\r
- accounted for as best it can be, but using the tickless mode will\r
- inevitably result in some tiny drift of the time maintained by the\r
- kernel with respect to calendar time. */\r
- ulSysTickCTRL = portNVIC_SYSTICK_CTRL_REG;\r
- portNVIC_SYSTICK_CTRL_REG = ( ulSysTickCTRL & ~portNVIC_SYSTICK_ENABLE_BIT );\r
-\r
- /* Re-enable interrupts - see comments above __disable_irq() call\r
- above. */\r
+ /* Re-enable interrupts to allow the interrupt that brought the MCU\r
+ out of sleep mode to execute immediately. see comments above\r
+ __disable_interrupt() call above. */\r
__enable_irq();\r
-\r
- if( ( ulSysTickCTRL & portNVIC_SYSTICK_COUNT_FLAG_BIT ) != 0 )\r
+ __dsb( portSY_FULL_READ_WRITE );\r
+ __isb( portSY_FULL_READ_WRITE );\r
+\r
+ /* Disable interrupts again because the clock is about to be stopped\r
+ and interrupts that execute while the clock is stopped will increase\r
+ any slippage between the time maintained by the RTOS and calendar\r
+ time. */\r
+ __disable_irq();\r
+ __dsb( portSY_FULL_READ_WRITE );\r
+ __isb( portSY_FULL_READ_WRITE );\r
+ \r
+ /* Disable the SysTick clock without reading the \r
+ portNVIC_SYSTICK_CTRL_REG register to ensure the\r
+ portNVIC_SYSTICK_COUNT_FLAG_BIT is not cleared if it is set. Again, \r
+ the time the SysTick is stopped for is accounted for as best it can \r
+ be, but using the tickless mode will inevitably result in some tiny \r
+ drift of the time maintained by the kernel with respect to calendar \r
+ time*/\r
+ portNVIC_SYSTICK_CTRL_REG = ( portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT );\r
+\r
+ /* Determine if the SysTick clock has already counted to zero and\r
+ been set back to the current reload value (the reload back being\r
+ correct for the entire expected idle time) or if the SysTick is yet\r
+ to count to zero (in which case an interrupt other than the SysTick\r
+ must have brought the system out of sleep mode). */\r
+ if( ( portNVIC_SYSTICK_CTRL_REG & portNVIC_SYSTICK_COUNT_FLAG_BIT ) != 0 )\r
{\r
uint32_t ulCalculatedLoadValue;\r
\r
- /* The tick interrupt has already executed, and the SysTick\r
- count reloaded with ulReloadValue. Reset the\r
+ /* The tick interrupt is already pending, and the SysTick count\r
+ reloaded with ulReloadValue. Reset the\r
portNVIC_SYSTICK_LOAD_REG with whatever remains of this tick\r
period. */\r
ulCalculatedLoadValue = ( ulTimerCountsForOneTick - 1UL ) - ( ulReloadValue - portNVIC_SYSTICK_CURRENT_VALUE_REG );\r
\r
portNVIC_SYSTICK_LOAD_REG = ulCalculatedLoadValue;\r
\r
- /* The tick interrupt handler will already have pended the tick\r
- processing in the kernel. As the pending tick will be\r
- processed as soon as this function exits, the tick value\r
- maintained by the tick is stepped forward by one less than the\r
- time spent waiting. */\r
+ /* As the pending tick will be processed as soon as this\r
+ function exits, the tick value maintained by the tick is stepped\r
+ forward by one less than the time spent waiting. */\r
ulCompleteTickPeriods = xExpectedIdleTime - 1UL;\r
}\r
else\r
\r
/* Restart SysTick so it runs from portNVIC_SYSTICK_LOAD_REG\r
again, then set portNVIC_SYSTICK_LOAD_REG back to its standard\r
- value. The critical section is used to ensure the tick interrupt\r
- can only execute once in the case that the reload register is near\r
- zero. */\r
+ value. */\r
portNVIC_SYSTICK_CURRENT_VALUE_REG = 0UL;\r
- portENTER_CRITICAL();\r
- {\r
- portNVIC_SYSTICK_CTRL_REG |= portNVIC_SYSTICK_ENABLE_BIT;\r
- vTaskStepTick( ulCompleteTickPeriods );\r
- portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;\r
- }\r
- portEXIT_CRITICAL();\r
+ portNVIC_SYSTICK_CTRL_REG |= portNVIC_SYSTICK_ENABLE_BIT;\r
+ vTaskStepTick( ulCompleteTickPeriods );\r
+ portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;\r
+\r
+ /* Exit with interrpts enabled. */\r
+ __enable_irq();\r
}\r
}\r
\r
* Setup the SysTick timer to generate the tick interrupts at the required\r
* frequency.\r
*/\r
-#if configOVERRIDE_DEFAULT_TICK_CONFIGURATION == 0\r
+#if( configOVERRIDE_DEFAULT_TICK_CONFIGURATION == 0 )\r
\r
void vPortSetupTimerInterrupt( void )\r
{\r
/* Calculate the constants required to configure the tick interrupt. */\r
- #if configUSE_TICKLESS_IDLE == 1\r
+ #if( configUSE_TICKLESS_IDLE == 1 )\r
{\r
ulTimerCountsForOneTick = ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ );\r
xMaximumPossibleSuppressedTicks = portMAX_24_BIT_NUMBER / ulTimerCountsForOneTick;\r
devices by calling NVIC_SetPriorityGrouping( 0 ); before starting the\r
scheduler. Note however that some vendor specific peripheral libraries\r
assume a non-zero priority group setting, in which cases using a value\r
- of zero will result in unpredicable behaviour. */\r
+ of zero will result in unpredictable behaviour. */\r
configASSERT( ( portAIRCR_REG & portPRIORITY_GROUP_MASK ) <= ulMaxPRIGROUPValue );\r
}\r
\r
projects / freertos / commitdiff