/*\r
- FreeRTOS V7.3.0 - Copyright (C) 2012 Real Time Engineers Ltd.\r
+ FreeRTOS V7.5.2 - Copyright (C) 2013 Real Time Engineers Ltd.\r
\r
- FEATURES AND PORTS ARE ADDED TO FREERTOS ALL THE TIME. PLEASE VISIT \r
- http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.\r
+ VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.\r
\r
***************************************************************************\r
* *\r
- * FreeRTOS tutorial books are available in pdf and paperback. *\r
- * Complete, revised, and edited pdf reference manuals are also *\r
- * available. *\r
+ * FreeRTOS provides completely free yet professionally developed, *\r
+ * robust, strictly quality controlled, supported, and cross *\r
+ * platform software that has become a de facto standard. *\r
* *\r
- * Purchasing FreeRTOS documentation will not only help you, by *\r
- * ensuring you get running as quickly as possible and with an *\r
- * in-depth knowledge of how to use FreeRTOS, it will also help *\r
- * the FreeRTOS project to continue with its mission of providing *\r
- * professional grade, cross platform, de facto standard solutions *\r
- * for microcontrollers - completely free of charge! *\r
+ * Help yourself get started quickly and support the FreeRTOS *\r
+ * project by purchasing a FreeRTOS tutorial book, reference *\r
+ * manual, or both from: http://www.FreeRTOS.org/Documentation *\r
* *\r
- * >>> See http://www.FreeRTOS.org/Documentation for details. <<< *\r
- * *\r
- * Thank you for using FreeRTOS, and thank you for your support! *\r
+ * Thank you! *\r
* *\r
***************************************************************************\r
\r
-\r
This file is part of the FreeRTOS distribution.\r
\r
FreeRTOS is free software; you can redistribute it and/or modify it under\r
the terms of the GNU General Public License (version 2) as published by the\r
- Free Software Foundation AND MODIFIED BY the FreeRTOS exception.\r
- >>>NOTE<<< The modification to the GPL is included to allow you to\r
- distribute a combined work that includes FreeRTOS without being obliged to\r
- provide the source code for proprietary components outside of the FreeRTOS\r
- kernel. FreeRTOS is distributed in the hope that it will be useful, but\r
- WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY\r
- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for\r
- more details. You should have received a copy of the GNU General Public\r
- License and the FreeRTOS license exception along with FreeRTOS; if not it\r
- can be viewed here: http://www.freertos.org/a00114.html and also obtained\r
- by writing to Richard Barry, contact details for whom are available on the\r
- FreeRTOS WEB site.\r
+ Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.\r
+\r
+ >>! NOTE: The modification to the GPL is included to allow you to distribute\r
+ >>! a combined work that includes FreeRTOS without being obliged to provide\r
+ >>! the source code for proprietary components outside of the FreeRTOS\r
+ >>! kernel.\r
+\r
+ FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY\r
+ WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS\r
+ FOR A PARTICULAR PURPOSE. Full license text is available from the following\r
+ link: http://www.freertos.org/a00114.html\r
\r
1 tab == 4 spaces!\r
- \r
+\r
***************************************************************************\r
* *\r
* Having a problem? Start by reading the FAQ "My application does *\r
* *\r
***************************************************************************\r
\r
- \r
- http://www.FreeRTOS.org - Documentation, training, latest versions, license \r
- and contact details. \r
- \r
+ http://www.FreeRTOS.org - Documentation, books, training, latest versions,\r
+ license and Real Time Engineers Ltd. contact details.\r
+\r
http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,\r
- including FreeRTOS+Trace - an indispensable productivity tool.\r
+ including FreeRTOS+Trace - an indispensable productivity tool, a DOS\r
+ compatible FAT file system, and our tiny thread aware UDP/IP stack.\r
+\r
+ http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High\r
+ Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS\r
+ licenses offer ticketed support, indemnification and middleware.\r
+\r
+ http://www.SafeRTOS.com - High Integrity Systems also provide a safety\r
+ engineered and independently SIL3 certified version for use in safety and\r
+ mission critical applications that require provable dependability.\r
\r
- Real Time Engineers ltd license FreeRTOS to High Integrity Systems, who sell \r
- the code with commercial support, indemnification, and middleware, under \r
- the OpenRTOS brand: http://www.OpenRTOS.com. High Integrity Systems also\r
- provide a safety engineered and independently SIL3 certified version under \r
- the SafeRTOS brand: http://www.SafeRTOS.com.\r
+ 1 tab == 4 spaces!\r
*/\r
\r
/*-----------------------------------------------------------\r
\r
#ifndef configSYSTICK_CLOCK_HZ\r
#define configSYSTICK_CLOCK_HZ configCPU_CLOCK_HZ\r
- #if configUSE_TICKLESS_IDLE == 1\r
- static const unsigned long ulStoppedTimerCompensation = 45UL;\r
- #endif\r
-#else /* configSYSTICK_CLOCK_HZ */\r
- #if configUSE_TICKLESS_IDLE == 1\r
- /* Assumes the SysTick clock is slower than the CPU clock. */\r
- static const unsigned long ulStoppedTimerCompensation = 45UL / ( configCPU_CLOCK_HZ / configSYSTICK_CLOCK_HZ );\r
- #endif\r
-#endif /* configSYSTICK_CLOCK_HZ */\r
+#endif\r
\r
/* Constants required to manipulate the core. Registers first... */\r
#define portNVIC_SYSTICK_CTRL_REG ( * ( ( volatile unsigned long * ) 0xe000e010 ) )\r
#define portNVIC_SYSTICK_LOAD_REG ( * ( ( volatile unsigned long * ) 0xe000e014 ) )\r
#define portNVIC_SYSTICK_CURRENT_VALUE_REG ( * ( ( volatile unsigned long * ) 0xe000e018 ) )\r
-#define portNVIC_INT_CTRL_REG ( * ( ( volatile unsigned long * ) 0xe000ed04 ) )\r
#define portNVIC_SYSPRI2_REG ( * ( ( volatile unsigned long * ) 0xe000ed20 ) )\r
/* ...then bits in the registers. */\r
#define portNVIC_SYSTICK_CLK_BIT ( 1UL << 2UL )\r
#define portNVIC_SYSTICK_INT_BIT ( 1UL << 1UL )\r
#define portNVIC_SYSTICK_ENABLE_BIT ( 1UL << 0UL )\r
#define portNVIC_SYSTICK_COUNT_FLAG_BIT ( 1UL << 16UL )\r
-#define portNVIC_PENDSVSET_BIT ( 1UL << 28UL )\r
#define portNVIC_PENDSVCLEAR_BIT ( 1UL << 27UL )\r
#define portNVIC_PEND_SYSTICK_CLEAR_BIT ( 1UL << 25UL )\r
\r
-#define portNVIC_PENDSV_PRI ( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 16UL )\r
-#define portNVIC_SYSTICK_PRI ( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 24UL )\r
+#define portNVIC_PENDSV_PRI ( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 16UL )\r
+#define portNVIC_SYSTICK_PRI ( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 24UL )\r
+\r
+/* Constants required to check the validity of an interrupt priority. */\r
+#define portFIRST_USER_INTERRUPT_NUMBER ( 16 )\r
+#define portNVIC_IP_REGISTERS_OFFSET_16 ( 0xE000E3F0 )\r
+#define portAIRCR_REG ( * ( ( volatile unsigned long * ) 0xE000ED0C ) )\r
+#define portMAX_8_BIT_VALUE ( ( unsigned char ) 0xff )\r
+#define portTOP_BIT_OF_BYTE ( ( unsigned char ) 0x80 )\r
+#define portMAX_PRIGROUP_BITS ( ( unsigned char ) 7 )\r
+#define portPRIORITY_GROUP_MASK ( 0x07UL << 8UL )\r
+#define portPRIGROUP_SHIFT ( 8UL )\r
\r
/* Constants required to manipulate the VFP. */\r
#define portFPCCR ( ( volatile unsigned long * ) 0xe000ef34 ) /* Floating point context control register. */\r
#define portINITIAL_XPSR ( 0x01000000 )\r
#define portINITIAL_EXEC_RETURN ( 0xfffffffd )\r
\r
-/* The priority used by the kernel is assigned to a variable to make access\r
-from inline assembler easier. */\r
-const unsigned long ulKernelPriority = configKERNEL_INTERRUPT_PRIORITY;\r
+/* The systick is a 24-bit counter. */\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
\r
/* Each task maintains its own interrupt status in the critical nesting\r
variable. */\r
static unsigned portBASE_TYPE uxCriticalNesting = 0xaaaaaaaa;\r
\r
/*\r
- * Setup the timer to generate the tick interrupts.\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
+ * generate the tick interrupt.\r
*/\r
-static void prvSetupTimerInterrupt( void );\r
+void vPortSetupTimerInterrupt( void );\r
\r
/*\r
* Exception handlers.\r
/*\r
* The number of SysTick increments that make up one tick period.\r
*/\r
-static unsigned long ulTimerReloadValueForOneTick = 0;\r
+#if configUSE_TICKLESS_IDLE == 1\r
+ static unsigned long ulTimerCountsForOneTick = 0;\r
+#endif /* configUSE_TICKLESS_IDLE */\r
\r
/*\r
* The maximum number of tick periods that can be suppressed is limited by the\r
static unsigned long xMaximumPossibleSuppressedTicks = 0;\r
#endif /* configUSE_TICKLESS_IDLE */\r
\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
+ static unsigned long ulStoppedTimerCompensation = 0;\r
+#endif /* configUSE_TICKLESS_IDLE */\r
+\r
+/*\r
+ * Used by the portASSERT_IF_INTERRUPT_PRIORITY_INVALID() macro to ensure \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
+ static unsigned char ucMaxSysCallPriority = 0;\r
+ static unsigned long ulMaxPRIGROUPValue = 0;\r
+ static const volatile unsigned char * const pcInterruptPriorityRegisters = ( const volatile unsigned char * const ) portNVIC_IP_REGISTERS_OFFSET_16;\r
+#endif /* configASSERT_DEFINED */\r
\r
/*-----------------------------------------------------------*/\r
\r
See http://www.FreeRTOS.org/RTOS-Cortex-M3-M4.html */\r
configASSERT( configMAX_SYSCALL_INTERRUPT_PRIORITY );\r
\r
- /* Make PendSV, CallSV and SysTick the same priroity as the kernel. */\r
+ #if( configASSERT_DEFINED == 1 )\r
+ {\r
+ volatile unsigned long ulOriginalPriority;\r
+ volatile char * const pcFirstUserPriorityRegister = ( volatile char * const ) ( portNVIC_IP_REGISTERS_OFFSET_16 + portFIRST_USER_INTERRUPT_NUMBER );\r
+ volatile unsigned char ucMaxPriorityValue;\r
+\r
+ /* Determine the maximum priority from which ISR safe FreeRTOS API\r
+ functions can be called. ISR safe functions are those that end in\r
+ "FromISR". FreeRTOS maintains separate thread and ISR API functions to\r
+ ensure interrupt entry is as fast and simple as possible.\r
+\r
+ Save the interrupt priority value that is about to be clobbered. */\r
+ ulOriginalPriority = *pcFirstUserPriorityRegister;\r
+\r
+ /* Determine the number of priority bits available. First write to all\r
+ possible bits. */\r
+ *pcFirstUserPriorityRegister = portMAX_8_BIT_VALUE;\r
+\r
+ /* Read the value back to see how many bits stuck. */\r
+ ucMaxPriorityValue = *pcFirstUserPriorityRegister;\r
+\r
+ /* Use the same mask on the maximum system call priority. */\r
+ ucMaxSysCallPriority = configMAX_SYSCALL_INTERRUPT_PRIORITY & ucMaxPriorityValue;\r
+\r
+ /* Calculate the maximum acceptable priority group value for the number\r
+ of bits read back. */\r
+ ulMaxPRIGROUPValue = portMAX_PRIGROUP_BITS;\r
+ while( ( ucMaxPriorityValue & portTOP_BIT_OF_BYTE ) == portTOP_BIT_OF_BYTE )\r
+ {\r
+ ulMaxPRIGROUPValue--;\r
+ ucMaxPriorityValue <<= ( unsigned char ) 0x01;\r
+ }\r
+\r
+ /* Shift the priority group value back to its position within the AIRCR\r
+ register. */\r
+ ulMaxPRIGROUPValue <<= portPRIGROUP_SHIFT;\r
+ ulMaxPRIGROUPValue &= portPRIORITY_GROUP_MASK;\r
+\r
+ /* Restore the clobbered interrupt priority register to its original\r
+ value. */\r
+ *pcFirstUserPriorityRegister = ulOriginalPriority;\r
+ }\r
+ #endif /* conifgASSERT_DEFINED */\r
+\r
+ /* Make PendSV and SysTick the lowest priority interrupts. */\r
portNVIC_SYSPRI2_REG |= portNVIC_PENDSV_PRI;\r
portNVIC_SYSPRI2_REG |= portNVIC_SYSTICK_PRI;\r
\r
/* Start the timer that generates the tick ISR. Interrupts are disabled\r
here already. */\r
- prvSetupTimerInterrupt();\r
+ vPortSetupTimerInterrupt();\r
\r
/* Initialise the critical nesting count ready for the first task. */\r
uxCriticalNesting = 0;\r
}\r
/*-----------------------------------------------------------*/\r
\r
-void vPortYieldFromISR( void )\r
+void vPortYield( void )\r
{\r
/* Set a PendSV to request a context switch. */\r
portNVIC_INT_CTRL_REG = portNVIC_PENDSVSET_BIT;\r
+\r
+ /* Barriers are normally not required but do ensure the code is completely\r
+ within the specified behaviour for the architecture. */\r
+ __asm volatile( "dsb" );\r
+ __asm volatile( "isb" );\r
}\r
/*-----------------------------------------------------------*/\r
\r
{\r
portDISABLE_INTERRUPTS();\r
uxCriticalNesting++;\r
+ __asm volatile( "dsb" );\r
+ __asm volatile( "isb" );\r
}\r
/*-----------------------------------------------------------*/\r
\r
" bx lr \n" \\r
:::"r0" \\r
);\r
+\r
+ /* Just to avoid compiler warnings. */\r
+ ( void ) ulNewMaskValue;\r
}\r
/*-----------------------------------------------------------*/\r
\r
\r
void xPortSysTickHandler( void )\r
{\r
- /* If using preemption, also force a context switch. */\r
- #if configUSE_PREEMPTION == 1\r
- portNVIC_INT_CTRL_REG = portNVIC_PENDSVSET_BIT;\r
- #endif\r
-\r
- #if configUSE_TICKLESS_IDLE == 1\r
- portNVIC_SYSTICK_LOAD_REG = ulTimerReloadValueForOneTick;\r
- #endif\r
-\r
+ /* The SysTick runs at the lowest interrupt priority, so when this interrupt\r
+ executes all interrupts must be unmasked. There is therefore no need to\r
+ save and then restore the interrupt mask value as its value is already\r
+ known. */\r
( void ) portSET_INTERRUPT_MASK_FROM_ISR();\r
{\r
- vTaskIncrementTick();\r
+ /* Increment the RTOS tick. */\r
+ if( xTaskIncrementTick() != pdFALSE )\r
+ {\r
+ /* A context switch is required. Context switching is performed in\r
+ the PendSV interrupt. Pend the PendSV interrupt. */\r
+ portNVIC_INT_CTRL_REG = portNVIC_PENDSVSET_BIT;\r
+ }\r
}\r
portCLEAR_INTERRUPT_MASK_FROM_ISR( 0 );\r
}\r
\r
__attribute__((weak)) void vPortSuppressTicksAndSleep( portTickType xExpectedIdleTime )\r
{\r
- unsigned long ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickIncrements;\r
+ unsigned long ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickDecrements;\r
+ portTickType xModifiableIdleTime;\r
\r
/* Make sure the SysTick reload value does not overflow the counter. */\r
if( xExpectedIdleTime > xMaximumPossibleSuppressedTicks )\r
xExpectedIdleTime = xMaximumPossibleSuppressedTicks;\r
}\r
\r
+ /* Stop the SysTick momentarily. The time the SysTick is stopped for\r
+ is 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
+ portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT;\r
+\r
/* Calculate the reload value required to wait xExpectedIdleTime\r
tick periods. -1 is used because this code will execute part way\r
- through one of the tick periods, and the fraction of a tick period is\r
- accounted for later. */\r
- ulReloadValue = ( ulTimerReloadValueForOneTick * ( xExpectedIdleTime - 1UL ) );\r
+ through one of the tick periods. */\r
+ ulReloadValue = portNVIC_SYSTICK_CURRENT_VALUE_REG + ( ulTimerCountsForOneTick * ( xExpectedIdleTime - 1UL ) );\r
if( ulReloadValue > ulStoppedTimerCompensation )\r
{\r
ulReloadValue -= ulStoppedTimerCompensation;\r
}\r
\r
- /* Stop the SysTick momentarily. The time the SysTick is stopped for\r
- is 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
- portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT;\r
+ /* Enter a critical section but don't use the taskENTER_CRITICAL()\r
+ method as that will mask interrupts that should exit sleep mode. */\r
+ __asm volatile( "cpsid i" );\r
\r
- /* If a context switch is pending then abandon the low power entry as\r
- the context switch might have been pended by an external interrupt that\r
- requires processing. */\r
- if( ( portNVIC_INT_CTRL_REG & portNVIC_PENDSVSET_BIT ) != 0 )\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
/* Restart SysTick. */\r
portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT | portNVIC_SYSTICK_ENABLE_BIT;\r
+\r
+ /* Re-enable interrupts - see comments above the cpsid instruction()\r
+ above. */\r
+ __asm volatile( "cpsie i" );\r
}\r
else\r
{\r
- /* Adjust the reload value to take into account that the current\r
- time slice is already partially complete. */\r
- ulReloadValue += ( portNVIC_SYSTICK_LOAD_REG - ( portNVIC_SYSTICK_LOAD_REG - portNVIC_SYSTICK_CURRENT_VALUE_REG ) );\r
+ /* Set the new reload value. */\r
portNVIC_SYSTICK_LOAD_REG = ulReloadValue;\r
\r
/* Clear the SysTick count flag and set the count value back to\r
/* Restart SysTick. */\r
portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT | portNVIC_SYSTICK_ENABLE_BIT;\r
\r
- /* Sleep until something happens. */\r
- portPRE_SLEEP_PROCESSING();\r
- __asm volatile( "wfi" );\r
- portPOST_SLEEP_PROCESSING();\r
+ /* Sleep until something happens. configPRE_SLEEP_PROCESSING() can\r
+ set its parameter to 0 to indicate that its implementation contains\r
+ its own wait for interrupt or wait for event instruction, and so wfi\r
+ should not be executed again. However, the original expected idle\r
+ time variable must remain unmodified, so a copy is taken. */\r
+ xModifiableIdleTime = xExpectedIdleTime;\r
+ configPRE_SLEEP_PROCESSING( xModifiableIdleTime );\r
+ if( xModifiableIdleTime > 0 )\r
+ {\r
+ __asm volatile( "dsb" );\r
+ __asm volatile( "wfi" );\r
+ __asm volatile( "isb" );\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
kernel with respect to calendar time. */\r
portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT;\r
\r
+ /* Re-enable interrupts - see comments above the cpsid instruction()\r
+ above. */\r
+ __asm volatile( "cpsie i" );\r
+\r
if( ( portNVIC_SYSTICK_CTRL_REG & portNVIC_SYSTICK_COUNT_FLAG_BIT ) != 0 )\r
{\r
/* The tick interrupt has already executed, and the SysTick\r
- count reloaded with the portNVIC_SYSTICK_LOAD_REG value.\r
- Reset the portNVIC_SYSTICK_LOAD_REG with whatever remains of\r
- this tick period. */\r
- portNVIC_SYSTICK_LOAD_REG = ulTimerReloadValueForOneTick - ( ulReloadValue - portNVIC_SYSTICK_CURRENT_VALUE_REG );\r
+ count reloaded with ulReloadValue. Reset the\r
+ portNVIC_SYSTICK_LOAD_REG with whatever remains of this tick\r
+ period. */\r
+ portNVIC_SYSTICK_LOAD_REG = ( ulTimerCountsForOneTick - 1UL ) - ( ulReloadValue - portNVIC_SYSTICK_CURRENT_VALUE_REG );\r
\r
/* The tick interrupt handler will already have pended the tick\r
processing in the kernel. As the pending tick will be\r
else\r
{\r
/* Something other than the tick interrupt ended the sleep.\r
- Work out how long the sleep lasted. */\r
- ulCompletedSysTickIncrements = ( xExpectedIdleTime * ulTimerReloadValueForOneTick ) - portNVIC_SYSTICK_CURRENT_VALUE_REG;\r
+ Work out how long the sleep lasted rounded to complete tick\r
+ periods (not the ulReload value which accounted for part\r
+ ticks). */\r
+ ulCompletedSysTickDecrements = ( xExpectedIdleTime * ulTimerCountsForOneTick ) - portNVIC_SYSTICK_CURRENT_VALUE_REG;\r
\r
/* How many complete tick periods passed while the processor\r
was waiting? */\r
- ulCompleteTickPeriods = ulCompletedSysTickIncrements / ulTimerReloadValueForOneTick;\r
+ ulCompleteTickPeriods = ulCompletedSysTickDecrements / ulTimerCountsForOneTick;\r
\r
/* The reload value is set to whatever fraction of a single tick\r
period remains. */\r
- portNVIC_SYSTICK_LOAD_REG = ( ( ulCompleteTickPeriods + 1 ) * ulTimerReloadValueForOneTick ) - ulCompletedSysTickIncrements;\r
+ portNVIC_SYSTICK_LOAD_REG = ( ( ulCompleteTickPeriods + 1 ) * 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. */\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
portNVIC_SYSTICK_CURRENT_VALUE_REG = 0UL;\r
- portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT | portNVIC_SYSTICK_ENABLE_BIT;\r
-\r
- vTaskStepTick( ulCompleteTickPeriods );\r
+ portENTER_CRITICAL();\r
+ {\r
+ portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT | portNVIC_SYSTICK_ENABLE_BIT;\r
+ vTaskStepTick( ulCompleteTickPeriods );\r
+ portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;\r
+ }\r
+ portEXIT_CRITICAL();\r
}\r
}\r
\r
* Setup the systick timer to generate the tick interrupts at the required\r
* frequency.\r
*/\r
-void prvSetupTimerInterrupt( void )\r
+__attribute__(( weak )) void vPortSetupTimerInterrupt( void )\r
{\r
/* Calculate the constants required to configure the tick interrupt. */\r
- ulTimerReloadValueForOneTick = ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ ) - 1UL;\r
#if configUSE_TICKLESS_IDLE == 1\r
- xMaximumPossibleSuppressedTicks = 0xffffffUL / ( ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ ) - 1UL );\r
+ {\r
+ ulTimerCountsForOneTick = ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ );\r
+ xMaximumPossibleSuppressedTicks = portMAX_24_BIT_NUMBER / ulTimerCountsForOneTick;\r
+ ulStoppedTimerCompensation = portMISSED_COUNTS_FACTOR / ( configCPU_CLOCK_HZ / configSYSTICK_CLOCK_HZ );\r
+ }\r
#endif /* configUSE_TICKLESS_IDLE */\r
\r
-\r
/* Configure SysTick to interrupt at the requested rate. */\r
- portNVIC_SYSTICK_LOAD_REG = ulTimerReloadValueForOneTick;\r
+ portNVIC_SYSTICK_LOAD_REG = ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ ) - 1UL;;\r
portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT | portNVIC_SYSTICK_ENABLE_BIT;\r
}\r
/*-----------------------------------------------------------*/\r
" bx r14 "\r
);\r
}\r
+/*-----------------------------------------------------------*/\r
+\r
+#if( configASSERT_DEFINED == 1 )\r
+\r
+ void vPortValidateInterruptPriority( void )\r
+ {\r
+ unsigned long ulCurrentInterrupt;\r
+ unsigned char ucCurrentPriority;\r
+\r
+ /* Obtain the number of the currently executing interrupt. */\r
+ __asm volatile( "mrs %0, ipsr" : "=r"( ulCurrentInterrupt ) );\r
+\r
+ /* Is the interrupt number a user defined interrupt? */\r
+ if( ulCurrentInterrupt >= portFIRST_USER_INTERRUPT_NUMBER )\r
+ {\r
+ /* Look up the interrupt's priority. */\r
+ ucCurrentPriority = pcInterruptPriorityRegisters[ ulCurrentInterrupt ];\r
+\r
+ /* The following assertion will fail if a service routine (ISR) for\r
+ an interrupt that has been assigned a priority above\r
+ configMAX_SYSCALL_INTERRUPT_PRIORITY calls an ISR safe FreeRTOS API\r
+ function. ISR safe FreeRTOS API functions must *only* be called\r
+ from interrupts that have been assigned a priority at or below\r
+ configMAX_SYSCALL_INTERRUPT_PRIORITY.\r
+\r
+ Numerically low interrupt priority numbers represent logically high\r
+ interrupt priorities, therefore the priority of the interrupt must\r
+ be set to a value equal to or numerically *higher* than\r
+ configMAX_SYSCALL_INTERRUPT_PRIORITY.\r
+\r
+ Interrupts that use the FreeRTOS API must not be left at their\r
+ default priority of zero as that is the highest possible priority,\r
+ which is guaranteed to be above configMAX_SYSCALL_INTERRUPT_PRIORITY,\r
+ and therefore also guaranteed to be invalid.\r
+\r
+ FreeRTOS maintains separate thread and ISR API functions to ensure\r
+ interrupt entry is as fast and simple as possible.\r
+\r
+ The following links provide detailed information:\r
+ http://www.freertos.org/RTOS-Cortex-M3-M4.html\r
+ http://www.freertos.org/FAQHelp.html */\r
+ configASSERT( ucCurrentPriority >= ucMaxSysCallPriority );\r
+ }\r
+\r
+ /* Priority grouping: The interrupt controller (NVIC) allows the bits\r
+ that define each interrupt's priority to be split between bits that\r
+ define the interrupt's pre-emption priority bits and bits that define\r
+ the interrupt's sub-priority. For simplicity all bits must be defined\r
+ to be pre-emption priority bits. The following assertion will fail if\r
+ this is not the case (if some bits represent a sub-priority).\r
+\r
+ If the application only uses CMSIS libraries for interrupt\r
+ configuration then the correct setting can be achieved on all Cortex-M\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
+ configASSERT( ( portAIRCR_REG & portPRIORITY_GROUP_MASK ) <= ulMaxPRIGROUPValue );\r
+ }\r
+\r
+#endif /* configASSERT_DEFINED */\r
+\r
\r
projects / freertos / blobdiff