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https://github.com/FreeRTOS/FreeRTOS-Kernel.git
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Add tickless idle support in Cortex-M ports.
Change CCS R4 directory name.
This commit is contained in:
Richard Barry
parent
6ec4c7cecb
commit
e03ab659f3
21 changed files with 2395 additions and 596 deletions
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@ -1,6 +1,6 @@
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/*
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FreeRTOS V7.2.0 - Copyright (C) 2012 Real Time Engineers Ltd.
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***************************************************************************
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* *
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@ -40,7 +40,7 @@
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FreeRTOS WEB site.
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1 tab == 4 spaces!
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***************************************************************************
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* *
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* Having a problem? Start by reading the FAQ "My application does *
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@ -50,17 +50,17 @@
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* *
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***************************************************************************
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http://www.FreeRTOS.org - Documentation, training, latest information,
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http://www.FreeRTOS.org - Documentation, training, latest information,
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license and contact details.
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http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
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including FreeRTOS+Trace - an indispensable productivity tool.
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Real Time Engineers ltd license FreeRTOS to High Integrity Systems, who sell
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the code with commercial support, indemnification, and middleware, under
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Real Time Engineers ltd license FreeRTOS to High Integrity Systems, who sell
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the code with commercial support, indemnification, and middleware, under
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the OpenRTOS brand: http://www.OpenRTOS.com. High Integrity Systems also
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provide a safety engineered and independently SIL3 certified version under
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provide a safety engineered and independently SIL3 certified version under
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the SafeRTOS brand: http://www.SafeRTOS.com.
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*/
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@ -76,15 +76,33 @@
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#error configMAX_SYSCALL_INTERRUPT_PRIORITY must not be set to 0. See http://www.FreeRTOS.org/RTOS-Cortex-M3-M4.html
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#endif
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/* Constants required to manipulate the NVIC. */
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#define portNVIC_SYSTICK_CTRL ( ( volatile unsigned long *) 0xe000e010 )
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#define portNVIC_SYSTICK_LOAD ( ( volatile unsigned long *) 0xe000e014 )
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#define portNVIC_INT_CTRL ( ( volatile unsigned long *) 0xe000ed04 )
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#define portNVIC_SYSPRI2 ( ( volatile unsigned long *) 0xe000ed20 )
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#define portNVIC_SYSTICK_CLK 0x00000004
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#define portNVIC_SYSTICK_INT 0x00000002
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#define portNVIC_SYSTICK_ENABLE 0x00000001
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#define portNVIC_PENDSVSET 0x10000000
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#ifndef configSYSTICK_CLOCK_HZ
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#define configSYSTICK_CLOCK_HZ configCPU_CLOCK_HZ
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#if configUSE_TICKLESS_IDLE == 1
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static const unsigned long ulStoppedTimerCompensation = 45UL;
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#endif
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#else /* configSYSTICK_CLOCK_HZ */
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#if configUSE_TICKLESS_IDLE == 1
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/* Assumes the SysTick clock is slower than the CPU clock. */
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static const unsigned long ulStoppedTimerCompensation = 45UL / ( configCPU_CLOCK_HZ / configSYSTICK_CLOCK_HZ );
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#endif
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#endif /* configSYSTICK_CLOCK_HZ */
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/* Constants required to manipulate the core. Registers first... */
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#define portNVIC_SYSTICK_CTRL_REG ( * ( ( volatile unsigned long * ) 0xe000e010 ) )
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#define portNVIC_SYSTICK_LOAD_REG ( * ( ( volatile unsigned long * ) 0xe000e014 ) )
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#define portNVIC_SYSTICK_CURRENT_VALUE_REG ( * ( ( volatile unsigned long * ) 0xe000e018 ) )
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#define portNVIC_INT_CTRL_REG ( * ( ( volatile unsigned long * ) 0xe000ed04 ) )
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#define portNVIC_SYSPRI2_REG ( * ( ( volatile unsigned long * ) 0xe000ed20 ) )
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/* ...then bits in the registers. */
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#define portNVIC_SYSTICK_CLK_BIT ( 1UL << 2UL )
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#define portNVIC_SYSTICK_INT_BIT ( 1UL << 1UL )
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#define portNVIC_SYSTICK_ENABLE_BIT ( 1UL << 0UL )
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#define portNVIC_SYSTICK_COUNT_FLAG_BIT ( 1UL << 16UL )
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#define portNVIC_PENDSVSET_BIT ( 1UL << 28UL )
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#define portNVIC_PENDSVCLEAR_BIT ( 1UL << 27UL )
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#define portNVIC_PEND_SYSTICK_CLEAR_BIT ( 1UL << 25UL )
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#define portNVIC_PENDSV_PRI ( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 16 )
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#define portNVIC_SYSTICK_PRI ( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 24 )
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@ -119,6 +137,21 @@ extern void vPortStartFirstTask( void );
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/*-----------------------------------------------------------*/
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/*
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* The number of SysTick increments that make up one tick period.
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*/
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static unsigned long ulTimerReloadValueForOneTick = 0;
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/*
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* The maximum number of tick periods that can be suppressed is limited by the
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* 24 bit resolution of the SysTick timer.
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*/
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#if configUSE_TICKLESS_IDLE == 1
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static unsigned long xMaximumPossibleSuppressedTicks = 0;
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#endif /* configUSE_TICKLESS_IDLE */
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/*-----------------------------------------------------------*/
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/*
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* See header file for description.
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*/
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@ -146,13 +179,13 @@ portSTACK_TYPE *pxPortInitialiseStack( portSTACK_TYPE *pxTopOfStack, pdTASK_CODE
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portBASE_TYPE xPortStartScheduler( void )
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{
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/* Make PendSV and SysTick the lowest priority interrupts. */
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*(portNVIC_SYSPRI2) |= portNVIC_PENDSV_PRI;
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*(portNVIC_SYSPRI2) |= portNVIC_SYSTICK_PRI;
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portNVIC_SYSPRI2_REG |= portNVIC_PENDSV_PRI;
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portNVIC_SYSPRI2_REG |= portNVIC_SYSTICK_PRI;
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/* Start the timer that generates the tick ISR. Interrupts are disabled
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here already. */
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prvSetupTimerInterrupt();
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/* Initialise the critical nesting count ready for the first task. */
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uxCriticalNesting = 0;
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@ -174,7 +207,7 @@ void vPortEndScheduler( void )
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void vPortYieldFromISR( void )
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{
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/* Set a PendSV to request a context switch. */
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*(portNVIC_INT_CTRL) = portNVIC_PENDSVSET;
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portNVIC_INT_CTRL_REG = portNVIC_PENDSVSET_BIT;
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}
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/*-----------------------------------------------------------*/
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@ -197,30 +230,142 @@ void vPortExitCritical( void )
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void xPortSysTickHandler( void )
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{
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unsigned long ulDummy;
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/* If using preemption, also force a context switch. */
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#if configUSE_PREEMPTION == 1
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*(portNVIC_INT_CTRL) = portNVIC_PENDSVSET;
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portNVIC_INT_CTRL_REG = portNVIC_PENDSVSET_BIT;
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#endif
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ulDummy = portSET_INTERRUPT_MASK_FROM_ISR();
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#if configUSE_TICKLESS_IDLE == 1
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portNVIC_SYSTICK_LOAD_REG = ulTimerReloadValueForOneTick;
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#endif
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( void ) portSET_INTERRUPT_MASK_FROM_ISR();
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{
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vTaskIncrementTick();
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}
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portCLEAR_INTERRUPT_MASK_FROM_ISR( ulDummy );
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portCLEAR_INTERRUPT_MASK_FROM_ISR( 0 );
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}
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/*-----------------------------------------------------------*/
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#if configUSE_TICKLESS_IDLE == 1
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__weak void vPortSuppressTicksAndSleep( portTickType xExpectedIdleTime )
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{
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unsigned long ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickIncrements;
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/* Make sure the SysTick reload value does not overflow the counter. */
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if( xExpectedIdleTime > xMaximumPossibleSuppressedTicks )
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{
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xExpectedIdleTime = xMaximumPossibleSuppressedTicks;
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}
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/* Calculate the reload value required to wait xExpectedIdleTime
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tick periods. -1 is used because this code will execute part way
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through one of the tick periods, and the fraction of a tick period is
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accounted for later. */
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ulReloadValue = ( ulTimerReloadValueForOneTick * ( xExpectedIdleTime - 1UL ) );
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if( ulReloadValue > ulStoppedTimerCompensation )
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{
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ulReloadValue -= ulStoppedTimerCompensation;
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}
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/* Stop the SysTick momentarily. The time the SysTick is stopped for
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is accounted for as best it can be, but using the tickless mode will
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inevitably result in some tiny drift of the time maintained by the
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kernel with respect to calendar time. */
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portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT;
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/* If a context switch is pending then abandon the low power entry as
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the context switch might have been pended by an external interrupt that
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requires processing. */
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if( ( portNVIC_INT_CTRL_REG & portNVIC_PENDSVSET_BIT ) != 0 )
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{
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/* Restart SysTick. */
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portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT | portNVIC_SYSTICK_ENABLE_BIT;
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}
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else
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{
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/* Adjust the reload value to take into account that the current
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time slice is already partially complete. */
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ulReloadValue += ( portNVIC_SYSTICK_LOAD_REG - ( portNVIC_SYSTICK_LOAD_REG - portNVIC_SYSTICK_CURRENT_VALUE_REG ) );
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portNVIC_SYSTICK_LOAD_REG = ulReloadValue;
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/* Clear the SysTick count flag and set the count value back to
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zero. */
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portNVIC_SYSTICK_CURRENT_VALUE_REG = 0UL;
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/* Restart SysTick. */
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portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT | portNVIC_SYSTICK_ENABLE_BIT;
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/* Sleep until something happens. */
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portPRE_SLEEP_PROCESSING();
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__WFI();
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portPOST_SLEEP_PROCESSING();
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/* Stop SysTick. Again, the time the SysTick is stopped for is
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accounted for as best it can be, but using the tickless mode will
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inevitably result in some tiny drift of the time maintained by the
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kernel with respect to calendar time. */
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portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT;
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if( ( portNVIC_SYSTICK_CTRL_REG & portNVIC_SYSTICK_COUNT_FLAG_BIT ) != 0 )
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{
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/* The tick interrupt has already executed, and the SysTick
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count reloaded with the portNVIC_SYSTICK_LOAD_REG value.
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Reset the portNVIC_SYSTICK_LOAD_REG with whatever remains of
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this tick period. */
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portNVIC_SYSTICK_LOAD_REG = ulTimerReloadValueForOneTick - ( ulReloadValue - portNVIC_SYSTICK_CURRENT_VALUE_REG );
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/* The tick interrupt handler will already have pended the tick
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processing in the kernel. As the pending tick will be
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processed as soon as this function exits, the tick value
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maintained by the tick is stepped forward by one less than the
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time spent waiting. */
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ulCompleteTickPeriods = xExpectedIdleTime - 1UL;
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}
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else
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{
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/* Something other than the tick interrupt ended the sleep.
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Work out how long the sleep lasted. */
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ulCompletedSysTickIncrements = ( xExpectedIdleTime * ulTimerReloadValueForOneTick ) - portNVIC_SYSTICK_CURRENT_VALUE_REG;
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/* How many complete tick periods passed while the processor
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was waiting? */
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ulCompleteTickPeriods = ulCompletedSysTickIncrements / ulTimerReloadValueForOneTick;
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/* The reload value is set to whatever fraction of a single tick
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period remains. */
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portNVIC_SYSTICK_LOAD_REG = ( ( ulCompleteTickPeriods + 1 ) * ulTimerReloadValueForOneTick ) - ulCompletedSysTickIncrements;
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}
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/* Restart SysTick so it runs from portNVIC_SYSTICK_LOAD_REG
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again, then set portNVIC_SYSTICK_LOAD_REG back to its standard
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value. */
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portNVIC_SYSTICK_CURRENT_VALUE_REG = 0UL;
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portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT | portNVIC_SYSTICK_ENABLE_BIT;
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vTaskStepTick( ulCompleteTickPeriods );
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}
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}
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#endif /* #if configUSE_TICKLESS_IDLE */
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/*-----------------------------------------------------------*/
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/*
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* Setup the systick timer to generate the tick interrupts at the required
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* frequency.
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*/
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void prvSetupTimerInterrupt( void )
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{
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/* Configure the constants required to setup the tick interrupt. */
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ulTimerReloadValueForOneTick = ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ ) - 1UL;
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#if configUSE_TICKLESS_IDLE == 1
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xMaximumPossibleSuppressedTicks = 0xffffffUL / ( ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ ) - 1UL );
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#endif /* configUSE_TICKLESS_IDLE */
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/* Configure SysTick to interrupt at the requested rate. */
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*(portNVIC_SYSTICK_LOAD) = ( configCPU_CLOCK_HZ / configTICK_RATE_HZ ) - 1UL;
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*(portNVIC_SYSTICK_CTRL) = portNVIC_SYSTICK_CLK | portNVIC_SYSTICK_INT | portNVIC_SYSTICK_ENABLE;
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portNVIC_SYSTICK_LOAD_REG = ulTimerReloadValueForOneTick;
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portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT | portNVIC_SYSTICK_ENABLE_BIT;
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}
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/*-----------------------------------------------------------*/
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