Refine the default tickless idle implementation in the Cortex-M3 port layers.
This commit is contained in:
Richard Barry
parent
08ca5dead5
commit
0c0b54c175
@ -95,26 +95,28 @@ FreeRTOS.org versions prior to V4.4.0 did not include this definition. */
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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 ) << 16UL )
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#define portNVIC_SYSTICK_PRI ( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 24UL )
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#define portNVIC_PENDSV_PRI ( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 16UL )
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#define portNVIC_SYSTICK_PRI ( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 24UL )
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/* Constants required to set up the initial stack. */
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#define portINITIAL_XPSR ( 0x01000000 )
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#define portINITIAL_XPSR ( 0x01000000 )
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/* The priority used by the kernel is assigned to a variable to make access
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from inline assembler easier. */
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const unsigned long ulKernelPriority = configKERNEL_INTERRUPT_PRIORITY;
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/* The systick is a 24-bit counter. */
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#define portMAX_24_BIT_NUMBER ( 0xffffffUL )
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/* A fiddle factor to estimate the number of SysTick counts that would have
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occurred while the SysTick counter is stopped during tickless idle
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calculations. */
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#define portMISSED_COUNTS_FACTOR ( 45UL )
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/* Each task maintains its own interrupt status in the critical nesting
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variable. */
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@ -145,8 +147,8 @@ static void prvPortStartFirstTask( void ) __attribute__ (( naked ));
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* The number of SysTick increments that make up one tick period.
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*/
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#if configUSE_TICKLESS_IDLE == 1
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static unsigned long ulTimerReloadValueForOneTick = 0;
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#endif
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static unsigned long ulTimerCountsForOneTick = 0;
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#endif /* configUSE_TICKLESS_IDLE */
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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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@ -229,7 +231,7 @@ portBASE_TYPE xPortStartScheduler( void )
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See http://www.FreeRTOS.org/RTOS-Cortex-M3-M4.html */
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configASSERT( configMAX_SYSCALL_INTERRUPT_PRIORITY );
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/* Make PendSV, CallSV and SysTick the same priroity as the kernel. */
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/* Make PendSV and SysTick the lowest priority interrupts. */
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portNVIC_SYSPRI2_REG |= portNVIC_PENDSV_PRI;
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portNVIC_SYSPRI2_REG |= portNVIC_SYSTICK_PRI;
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@ -354,20 +356,13 @@ void xPortPendSVHandler( void )
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void xPortSysTickHandler( void )
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{
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/* Only reset the systick load register if configUSE_TICKLESS_IDLE is set to
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1. If it is set to 0 tickless idle is not being used. If it is set to a
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value other than 0 or 1 then a timer other than the SysTick is being used
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to generate the tick interrupt. */
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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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/* The SysTick runs at the lowest interrupt priority, so when this interrupt
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executes all interrupts must be unmasked. There is therefore no need to
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save and then restore the interrupt mask value as its value is already
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known. */
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( void ) portSET_INTERRUPT_MASK_FROM_ISR();
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{
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/* Increment the RTOS tick. */
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if( xTaskIncrementTick() != pdFALSE )
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{
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/* A context switch is required. Context switching is performed in
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@ -383,7 +378,7 @@ void xPortSysTickHandler( void )
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__attribute__((weak)) void vPortSuppressTicksAndSleep( portTickType xExpectedIdleTime )
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{
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unsigned long ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickIncrements;
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unsigned long ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickDecrements;
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portTickType xModifiableIdleTime;
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/* Make sure the SysTick reload value does not overflow the counter. */
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@ -392,25 +387,20 @@ void xPortSysTickHandler( void )
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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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/* Adjust the reload value to take into account that the current time
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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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/* 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. */
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ulReloadValue = portNVIC_SYSTICK_CURRENT_VALUE_REG + ( ulTimerCountsForOneTick * ( 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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/* Enter a critical section but don't use the taskENTER_CRITICAL()
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method as that will mask interrupts that should exit sleep mode. */
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@ -467,10 +457,10 @@ void xPortSysTickHandler( void )
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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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count reloaded with ulReloadValue. Reset the
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portNVIC_SYSTICK_LOAD_REG with whatever remains of this tick
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period. */
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portNVIC_SYSTICK_LOAD_REG = ( ulTimerCountsForOneTick - 1UL ) - ( 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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@ -482,16 +472,18 @@ void xPortSysTickHandler( void )
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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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Work out how long the sleep lasted rounded to complete tick
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periods (not the ulReload value which accounted for part
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ticks). */
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ulCompletedSysTickDecrements = ( xExpectedIdleTime * ulTimerCountsForOneTick ) - 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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ulCompleteTickPeriods = ulCompletedSysTickDecrements / ulTimerCountsForOneTick;
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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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portNVIC_SYSTICK_LOAD_REG = ( ( ulCompleteTickPeriods + 1 ) * ulTimerCountsForOneTick ) - ulCompletedSysTickDecrements;
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}
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/* Restart SysTick so it runs from portNVIC_SYSTICK_LOAD_REG
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@ -501,6 +493,10 @@ void xPortSysTickHandler( void )
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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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/* The counter must start by the time the reload value is reset. */
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configASSERT( portNVIC_SYSTICK_CURRENT_VALUE_REG );
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portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;
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}
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}
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@ -516,9 +512,9 @@ __attribute__(( weak )) void vPortSetupTimerInterrupt( void )
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/* Calculate the constants required to configure the tick interrupt. */
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#if configUSE_TICKLESS_IDLE == 1
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{
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ulTimerReloadValueForOneTick = ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ ) - 1UL;
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xMaximumPossibleSuppressedTicks = 0xffffffUL / ( ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ ) - 1UL );
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ulStoppedTimerCompensation = 45UL / ( configCPU_CLOCK_HZ / configSYSTICK_CLOCK_HZ );
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ulTimerCountsForOneTick = ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ );
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xMaximumPossibleSuppressedTicks = portMAX_24_BIT_NUMBER / ulTimerCountsForOneTick;
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ulStoppedTimerCompensation = portMISSED_COUNTS_FACTOR / ( configCPU_CLOCK_HZ / configSYSTICK_CLOCK_HZ );
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}
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#endif /* configUSE_TICKLESS_IDLE */
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@ -101,8 +101,8 @@
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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 ) << 16UL )
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#define portNVIC_SYSTICK_PRI ( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 24UL )
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#define portNVIC_PENDSV_PRI ( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 16UL )
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#define portNVIC_SYSTICK_PRI ( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 24UL )
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/* Constants required to manipulate the VFP. */
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#define portFPCCR ( ( volatile unsigned long * ) 0xe000ef34 ) /* Floating point context control register. */
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@ -112,9 +112,13 @@
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#define portINITIAL_XPSR ( 0x01000000 )
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#define portINITIAL_EXEC_RETURN ( 0xfffffffd )
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/* The priority used by the kernel is assigned to a variable to make access
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from inline assembler easier. */
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const unsigned long ulKernelPriority = configKERNEL_INTERRUPT_PRIORITY;
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/* The systick is a 24-bit counter. */
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#define portMAX_24_BIT_NUMBER ( 0xffffffUL )
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/* A fiddle factor to estimate the number of SysTick counts that would have
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occurred while the SysTick counter is stopped during tickless idle
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calculations. */
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#define portMISSED_COUNTS_FACTOR ( 45UL )
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/* Each task maintains its own interrupt status in the critical nesting
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variable. */
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@ -150,8 +154,8 @@ static void prvPortStartFirstTask( void ) __attribute__ (( naked ));
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* The number of SysTick increments that make up one tick period.
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*/
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#if configUSE_TICKLESS_IDLE == 1
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static unsigned long ulTimerReloadValueForOneTick = 0;
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#endif
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static unsigned long ulTimerCountsForOneTick = 0;
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#endif /* configUSE_TICKLESS_IDLE */
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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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@ -245,7 +249,7 @@ portBASE_TYPE xPortStartScheduler( void )
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See http://www.FreeRTOS.org/RTOS-Cortex-M3-M4.html */
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configASSERT( configMAX_SYSCALL_INTERRUPT_PRIORITY );
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/* Make PendSV, CallSV and SysTick the same priroity as the kernel. */
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/* Make PendSV and SysTick the lowest priority interrupts. */
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portNVIC_SYSPRI2_REG |= portNVIC_PENDSV_PRI;
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portNVIC_SYSPRI2_REG |= portNVIC_SYSTICK_PRI;
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@ -387,20 +391,17 @@ void xPortPendSVHandler( void )
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void xPortSysTickHandler( void )
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{
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/* Only reset the systick load register if configUSE_TICKLESS_IDLE is set to
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1. If it is set to 0 tickless idle is not being used. If it is set to a
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value other than 0 or 1 then a timer other than the SysTick is being used
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to generate the tick interrupt. */
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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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/* The SysTick runs at the lowest interrupt priority, so when this interrupt
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executes all interrupts must be unmasked. There is therefore no need to
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save and then restore the interrupt mask value as its value is already
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known. */
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( void ) portSET_INTERRUPT_MASK_FROM_ISR();
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{
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/* Increment the RTOS tick count. */
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/* Increment the RTOS tick. */
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if( xTaskIncrementTick() != pdFALSE )
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{
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/* Pend a context switch. */
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/* A context switch is required. Context switching is performed in
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the PendSV interrupt. Pend the PendSV interrupt. */
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portNVIC_INT_CTRL_REG = portNVIC_PENDSVSET_BIT;
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}
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}
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@ -412,7 +413,7 @@ void xPortSysTickHandler( void )
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__attribute__((weak)) void vPortSuppressTicksAndSleep( portTickType xExpectedIdleTime )
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{
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unsigned long ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickIncrements;
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unsigned long ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickDecrements;
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portTickType xModifiableIdleTime;
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/* Make sure the SysTick reload value does not overflow the counter. */
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@ -421,25 +422,20 @@ void xPortSysTickHandler( void )
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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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/* Adjust the reload value to take into account that the current time
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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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/* 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. */
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ulReloadValue = portNVIC_SYSTICK_CURRENT_VALUE_REG + ( ulTimerCountsForOneTick * ( 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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/* Enter a critical section but don't use the taskENTER_CRITICAL()
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method as that will mask interrupts that should exit sleep mode. */
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@ -496,10 +492,10 @@ void xPortSysTickHandler( void )
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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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count reloaded with ulReloadValue. Reset the
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portNVIC_SYSTICK_LOAD_REG with whatever remains of this tick
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period. */
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portNVIC_SYSTICK_LOAD_REG = ( ulTimerCountsForOneTick - 1UL ) - ( 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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@ -511,16 +507,18 @@ void xPortSysTickHandler( void )
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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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Work out how long the sleep lasted rounded to complete tick
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periods (not the ulReload value which accounted for part
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ticks). */
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ulCompletedSysTickDecrements = ( xExpectedIdleTime * ulTimerCountsForOneTick ) - 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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ulCompleteTickPeriods = ulCompletedSysTickDecrements / ulTimerCountsForOneTick;
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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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portNVIC_SYSTICK_LOAD_REG = ( ( ulCompleteTickPeriods + 1 ) * ulTimerCountsForOneTick ) - ulCompletedSysTickDecrements;
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}
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/* Restart SysTick so it runs from portNVIC_SYSTICK_LOAD_REG
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@ -530,6 +528,10 @@ void xPortSysTickHandler( void )
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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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/* The counter must start by the time the reload value is reset. */
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configASSERT( portNVIC_SYSTICK_CURRENT_VALUE_REG );
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portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;
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}
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}
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@ -545,9 +547,9 @@ __attribute__(( weak )) void vPortSetupTimerInterrupt( void )
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/* Calculate the constants required to configure the tick interrupt. */
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#if configUSE_TICKLESS_IDLE == 1
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{
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ulTimerReloadValueForOneTick = ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ ) - 1UL;
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xMaximumPossibleSuppressedTicks = 0xffffffUL / ( ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ ) - 1UL );
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ulStoppedTimerCompensation = 45UL / ( configCPU_CLOCK_HZ / configSYSTICK_CLOCK_HZ );
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||||
ulTimerCountsForOneTick = ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ );
|
||||
xMaximumPossibleSuppressedTicks = portMAX_24_BIT_NUMBER / ulTimerCountsForOneTick;
|
||||
ulStoppedTimerCompensation = portMISSED_COUNTS_FACTOR / ( configCPU_CLOCK_HZ / configSYSTICK_CLOCK_HZ );
|
||||
}
|
||||
#endif /* configUSE_TICKLESS_IDLE */
|
||||
|
||||
|
||||
@ -104,17 +104,25 @@
|
||||
#define portNVIC_PENDSVCLEAR_BIT ( 1UL << 27UL )
|
||||
#define portNVIC_PEND_SYSTICK_CLEAR_BIT ( 1UL << 25UL )
|
||||
|
||||
#define portNVIC_PENDSV_PRI ( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 16 )
|
||||
#define portNVIC_SYSTICK_PRI ( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 24 )
|
||||
#define portNVIC_PENDSV_PRI ( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 16UL )
|
||||
#define portNVIC_SYSTICK_PRI ( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 24UL )
|
||||
|
||||
/* Constants required to set up the initial stack. */
|
||||
#define portINITIAL_XPSR ( 0x01000000 )
|
||||
#define portINITIAL_XPSR ( 0x01000000 )
|
||||
|
||||
/* The systick is a 24-bit counter. */
|
||||
#define portMAX_24_BIT_NUMBER ( 0xffffffUL )
|
||||
|
||||
/* A fiddle factor to estimate the number of SysTick counts that would have
|
||||
occurred while the SysTick counter is stopped during tickless idle
|
||||
calculations. */
|
||||
#define portMISSED_COUNTS_FACTOR ( 45UL )
|
||||
|
||||
/* For backward compatibility, ensure configKERNEL_INTERRUPT_PRIORITY is
|
||||
defined. The value 255 should also ensure backward compatibility.
|
||||
FreeRTOS.org versions prior to V4.3.0 did not include this definition. */
|
||||
#ifndef configKERNEL_INTERRUPT_PRIORITY
|
||||
#define configKERNEL_INTERRUPT_PRIORITY 0
|
||||
#define configKERNEL_INTERRUPT_PRIORITY 255
|
||||
#endif
|
||||
|
||||
/* Each task maintains its own interrupt status in the critical nesting
|
||||
@ -144,8 +152,8 @@ extern void vPortStartFirstTask( void );
|
||||
* The number of SysTick increments that make up one tick period.
|
||||
*/
|
||||
#if configUSE_TICKLESS_IDLE == 1
|
||||
static unsigned long ulTimerReloadValueForOneTick = 0;
|
||||
#endif
|
||||
static unsigned long ulTimerCountsForOneTick = 0;
|
||||
#endif /* configUSE_TICKLESS_IDLE */
|
||||
|
||||
/*
|
||||
* The maximum number of tick periods that can be suppressed is limited by the
|
||||
@ -250,18 +258,17 @@ void vPortExitCritical( void )
|
||||
|
||||
void xPortSysTickHandler( void )
|
||||
{
|
||||
/* Only reset the systick load register if configUSE_TICKLESS_IDLE is set to
|
||||
1. If it is set to 0 tickless idle is not being used. If it is set to a
|
||||
value other than 0 or 1 then a timer other than the SysTick is being used
|
||||
to generate the tick interrupt. */
|
||||
#if configUSE_TICKLESS_IDLE == 1
|
||||
portNVIC_SYSTICK_LOAD_REG = ulTimerReloadValueForOneTick;
|
||||
#endif
|
||||
|
||||
/* The SysTick runs at the lowest interrupt priority, so when this interrupt
|
||||
executes all interrupts must be unmasked. There is therefore no need to
|
||||
save and then restore the interrupt mask value as its value is already
|
||||
known. */
|
||||
( void ) portSET_INTERRUPT_MASK_FROM_ISR();
|
||||
{
|
||||
/* Increment the RTOS tick. */
|
||||
if( xTaskIncrementTick() != pdFALSE )
|
||||
{
|
||||
/* A context switch is required. Context switching is performed in
|
||||
the PendSV interrupt. Pend the PendSV interrupt. */
|
||||
portNVIC_INT_CTRL_REG = portNVIC_PENDSVSET_BIT;
|
||||
}
|
||||
}
|
||||
@ -273,7 +280,7 @@ void xPortSysTickHandler( void )
|
||||
|
||||
__weak void vPortSuppressTicksAndSleep( portTickType xExpectedIdleTime )
|
||||
{
|
||||
unsigned long ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickIncrements;
|
||||
unsigned long ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickDecrements;
|
||||
portTickType xModifiableIdleTime;
|
||||
|
||||
/* Make sure the SysTick reload value does not overflow the counter. */
|
||||
@ -282,25 +289,20 @@ void xPortSysTickHandler( void )
|
||||
xExpectedIdleTime = xMaximumPossibleSuppressedTicks;
|
||||
}
|
||||
|
||||
/* Calculate the reload value required to wait xExpectedIdleTime
|
||||
tick periods. -1 is used because this code will execute part way
|
||||
through one of the tick periods, and the fraction of a tick period is
|
||||
accounted for later. */
|
||||
ulReloadValue = ( ulTimerReloadValueForOneTick * ( xExpectedIdleTime - 1UL ) );
|
||||
if( ulReloadValue > ulStoppedTimerCompensation )
|
||||
{
|
||||
ulReloadValue -= ulStoppedTimerCompensation;
|
||||
}
|
||||
|
||||
/* Stop the SysTick momentarily. The time the SysTick is stopped for
|
||||
is accounted for as best it can be, but using the tickless mode will
|
||||
inevitably result in some tiny drift of the time maintained by the
|
||||
kernel with respect to calendar time. */
|
||||
portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT;
|
||||
|
||||
/* Adjust the reload value to take into account that the current
|
||||
time slice is already partially complete. */
|
||||
ulReloadValue += ( portNVIC_SYSTICK_LOAD_REG - ( portNVIC_SYSTICK_LOAD_REG - portNVIC_SYSTICK_CURRENT_VALUE_REG ) );
|
||||
/* Calculate the reload value required to wait xExpectedIdleTime
|
||||
tick periods. -1 is used because this code will execute part way
|
||||
through one of the tick periods. */
|
||||
ulReloadValue = portNVIC_SYSTICK_CURRENT_VALUE_REG + ( ulTimerCountsForOneTick * ( xExpectedIdleTime - 1UL ) );
|
||||
if( ulReloadValue > ulStoppedTimerCompensation )
|
||||
{
|
||||
ulReloadValue -= ulStoppedTimerCompensation;
|
||||
}
|
||||
|
||||
/* Enter a critical section but don't use the taskENTER_CRITICAL()
|
||||
method as that will mask interrupts that should exit sleep mode. */
|
||||
@ -357,10 +359,10 @@ void xPortSysTickHandler( void )
|
||||
if( ( portNVIC_SYSTICK_CTRL_REG & portNVIC_SYSTICK_COUNT_FLAG_BIT ) != 0 )
|
||||
{
|
||||
/* The tick interrupt has already executed, and the SysTick
|
||||
count reloaded with the portNVIC_SYSTICK_LOAD_REG value.
|
||||
Reset the portNVIC_SYSTICK_LOAD_REG with whatever remains of
|
||||
this tick period. */
|
||||
portNVIC_SYSTICK_LOAD_REG = ulTimerReloadValueForOneTick - ( ulReloadValue - portNVIC_SYSTICK_CURRENT_VALUE_REG );
|
||||
count reloaded with ulReloadValue. Reset the
|
||||
portNVIC_SYSTICK_LOAD_REG with whatever remains of this tick
|
||||
period. */
|
||||
portNVIC_SYSTICK_LOAD_REG = ( ulTimerCountsForOneTick - 1UL ) - ( ulReloadValue - portNVIC_SYSTICK_CURRENT_VALUE_REG );
|
||||
|
||||
/* The tick interrupt handler will already have pended the tick
|
||||
processing in the kernel. As the pending tick will be
|
||||
@ -372,16 +374,18 @@ void xPortSysTickHandler( void )
|
||||
else
|
||||
{
|
||||
/* Something other than the tick interrupt ended the sleep.
|
||||
Work out how long the sleep lasted. */
|
||||
ulCompletedSysTickIncrements = ( xExpectedIdleTime * ulTimerReloadValueForOneTick ) - portNVIC_SYSTICK_CURRENT_VALUE_REG;
|
||||
Work out how long the sleep lasted rounded to complete tick
|
||||
periods (not the ulReload value which accounted for part
|
||||
ticks). */
|
||||
ulCompletedSysTickDecrements = ( xExpectedIdleTime * ulTimerCountsForOneTick ) - portNVIC_SYSTICK_CURRENT_VALUE_REG;
|
||||
|
||||
/* How many complete tick periods passed while the processor
|
||||
was waiting? */
|
||||
ulCompleteTickPeriods = ulCompletedSysTickIncrements / ulTimerReloadValueForOneTick;
|
||||
ulCompleteTickPeriods = ulCompletedSysTickDecrements / ulTimerCountsForOneTick;
|
||||
|
||||
/* The reload value is set to whatever fraction of a single tick
|
||||
period remains. */
|
||||
portNVIC_SYSTICK_LOAD_REG = ( ( ulCompleteTickPeriods + 1 ) * ulTimerReloadValueForOneTick ) - ulCompletedSysTickIncrements;
|
||||
portNVIC_SYSTICK_LOAD_REG = ( ( ulCompleteTickPeriods + 1 ) * ulTimerCountsForOneTick ) - ulCompletedSysTickDecrements;
|
||||
}
|
||||
|
||||
/* Restart SysTick so it runs from portNVIC_SYSTICK_LOAD_REG
|
||||
@ -391,6 +395,10 @@ void xPortSysTickHandler( void )
|
||||
portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT | portNVIC_SYSTICK_ENABLE_BIT;
|
||||
|
||||
vTaskStepTick( ulCompleteTickPeriods );
|
||||
|
||||
/* The counter must start by the time the reload value is reset. */
|
||||
configASSERT( portNVIC_SYSTICK_CURRENT_VALUE_REG );
|
||||
portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;
|
||||
}
|
||||
}
|
||||
|
||||
@ -406,9 +414,9 @@ __weak void vPortSetupTimerInterrupt( void )
|
||||
/* Calculate the constants required to configure the tick interrupt. */
|
||||
#if configUSE_TICKLESS_IDLE == 1
|
||||
{
|
||||
ulTimerReloadValueForOneTick = ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ ) - 1UL;
|
||||
xMaximumPossibleSuppressedTicks = 0xffffffUL / ( ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ ) - 1UL );
|
||||
ulStoppedTimerCompensation = 45UL / ( configCPU_CLOCK_HZ / configSYSTICK_CLOCK_HZ );
|
||||
ulTimerCountsForOneTick = ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ );
|
||||
xMaximumPossibleSuppressedTicks = portMAX_24_BIT_NUMBER / ulTimerCountsForOneTick;
|
||||
ulStoppedTimerCompensation = portMISSED_COUNTS_FACTOR / ( configCPU_CLOCK_HZ / configSYSTICK_CLOCK_HZ );
|
||||
}
|
||||
#endif /* configUSE_TICKLESS_IDLE */
|
||||
|
||||
|
||||
@ -108,16 +108,25 @@
|
||||
#define portNVIC_PENDSVCLEAR_BIT ( 1UL << 27UL )
|
||||
#define portNVIC_PEND_SYSTICK_CLEAR_BIT ( 1UL << 25UL )
|
||||
|
||||
#define portNVIC_PENDSV_PRI ( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 16 )
|
||||
#define portNVIC_SYSTICK_PRI ( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 24 )
|
||||
#define portNVIC_PENDSV_PRI ( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 16UL )
|
||||
#define portNVIC_SYSTICK_PRI ( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 24UL )
|
||||
|
||||
/* Constants required to manipulate the VFP. */
|
||||
#define portFPCCR ( ( volatile unsigned long * ) 0xe000ef34 ) /* Floating point context control register. */
|
||||
#define portASPEN_AND_LSPEN_BITS ( 0x3UL << 30UL )
|
||||
#define portFPCCR ( ( volatile unsigned long * ) 0xe000ef34 ) /* Floating point context control register. */
|
||||
#define portASPEN_AND_LSPEN_BITS ( 0x3UL << 30UL )
|
||||
|
||||
/* Constants required to set up the initial stack. */
|
||||
#define portINITIAL_XPSR ( 0x01000000 )
|
||||
#define portINITIAL_EXEC_RETURN ( 0xfffffffd )
|
||||
#define portINITIAL_XPSR ( 0x01000000 )
|
||||
#define portINITIAL_EXEC_RETURN ( 0xfffffffd )
|
||||
|
||||
/* The systick is a 24-bit counter. */
|
||||
#define portMAX_24_BIT_NUMBER ( 0xffffffUL )
|
||||
|
||||
/* A fiddle factor to estimate the number of SysTick counts that would have
|
||||
occurred while the SysTick counter is stopped during tickless idle
|
||||
calculations. */
|
||||
#define portMISSED_COUNTS_FACTOR ( 45UL )
|
||||
|
||||
|
||||
/* Each task maintains its own interrupt status in the critical nesting
|
||||
variable. */
|
||||
@ -151,8 +160,8 @@ extern void vPortEnableVFP( void );
|
||||
* The number of SysTick increments that make up one tick period.
|
||||
*/
|
||||
#if configUSE_TICKLESS_IDLE == 1
|
||||
static unsigned long ulTimerReloadValueForOneTick = 0;
|
||||
#endif
|
||||
static unsigned long ulTimerCountsForOneTick = 0;
|
||||
#endif /* configUSE_TICKLESS_IDLE */
|
||||
|
||||
/*
|
||||
* The maximum number of tick periods that can be suppressed is limited by the
|
||||
@ -275,20 +284,17 @@ void vPortExitCritical( void )
|
||||
|
||||
void xPortSysTickHandler( void )
|
||||
{
|
||||
/* Only reset the systick load register if configUSE_TICKLESS_IDLE is set to
|
||||
1. If it is set to 0 tickless idle is not being used. If it is set to a
|
||||
value other than 0 or 1 then a timer other than the SysTick is being used
|
||||
to generate the tick interrupt. */
|
||||
#if configUSE_TICKLESS_IDLE == 1
|
||||
portNVIC_SYSTICK_LOAD_REG = ulTimerReloadValueForOneTick;
|
||||
#endif
|
||||
|
||||
/* The SysTick runs at the lowest interrupt priority, so when this interrupt
|
||||
executes all interrupts must be unmasked. There is therefore no need to
|
||||
save and then restore the interrupt mask value as its value is already
|
||||
known. */
|
||||
( void ) portSET_INTERRUPT_MASK_FROM_ISR();
|
||||
{
|
||||
/* Increment the RTOS tick. */
|
||||
if( xTaskIncrementTick() != pdFALSE )
|
||||
{
|
||||
/* Pend a context switch. */
|
||||
/* A context switch is required. Context switching is performed in
|
||||
the PendSV interrupt. Pend the PendSV interrupt. */
|
||||
portNVIC_INT_CTRL_REG = portNVIC_PENDSVSET_BIT;
|
||||
}
|
||||
}
|
||||
@ -300,7 +306,7 @@ void xPortSysTickHandler( void )
|
||||
|
||||
__weak void vPortSuppressTicksAndSleep( portTickType xExpectedIdleTime )
|
||||
{
|
||||
unsigned long ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickIncrements;
|
||||
unsigned long ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickDecrements;
|
||||
portTickType xModifiableIdleTime;
|
||||
|
||||
/* Make sure the SysTick reload value does not overflow the counter. */
|
||||
@ -309,25 +315,20 @@ void xPortSysTickHandler( void )
|
||||
xExpectedIdleTime = xMaximumPossibleSuppressedTicks;
|
||||
}
|
||||
|
||||
/* Calculate the reload value required to wait xExpectedIdleTime
|
||||
tick periods. -1 is used because this code will execute part way
|
||||
through one of the tick periods, and the fraction of a tick period is
|
||||
accounted for later. */
|
||||
ulReloadValue = ( ulTimerReloadValueForOneTick * ( xExpectedIdleTime - 1UL ) );
|
||||
if( ulReloadValue > ulStoppedTimerCompensation )
|
||||
{
|
||||
ulReloadValue -= ulStoppedTimerCompensation;
|
||||
}
|
||||
|
||||
/* Stop the SysTick momentarily. The time the SysTick is stopped for
|
||||
is accounted for as best it can be, but using the tickless mode will
|
||||
inevitably result in some tiny drift of the time maintained by the
|
||||
kernel with respect to calendar time. */
|
||||
portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT;
|
||||
|
||||
/* Adjust the reload value to take into account that the current
|
||||
time slice is already partially complete. */
|
||||
ulReloadValue += ( portNVIC_SYSTICK_LOAD_REG - ( portNVIC_SYSTICK_LOAD_REG - portNVIC_SYSTICK_CURRENT_VALUE_REG ) );
|
||||
/* Calculate the reload value required to wait xExpectedIdleTime
|
||||
tick periods. -1 is used because this code will execute part way
|
||||
through one of the tick periods. */
|
||||
ulReloadValue = portNVIC_SYSTICK_CURRENT_VALUE_REG + ( ulTimerCountsForOneTick * ( xExpectedIdleTime - 1UL ) );
|
||||
if( ulReloadValue > ulStoppedTimerCompensation )
|
||||
{
|
||||
ulReloadValue -= ulStoppedTimerCompensation;
|
||||
}
|
||||
|
||||
/* Enter a critical section but don't use the taskENTER_CRITICAL()
|
||||
method as that will mask interrupts that should exit sleep mode. */
|
||||
@ -384,10 +385,10 @@ void xPortSysTickHandler( void )
|
||||
if( ( portNVIC_SYSTICK_CTRL_REG & portNVIC_SYSTICK_COUNT_FLAG_BIT ) != 0 )
|
||||
{
|
||||
/* The tick interrupt has already executed, and the SysTick
|
||||
count reloaded with the portNVIC_SYSTICK_LOAD_REG value.
|
||||
Reset the portNVIC_SYSTICK_LOAD_REG with whatever remains of
|
||||
this tick period. */
|
||||
portNVIC_SYSTICK_LOAD_REG = ulTimerReloadValueForOneTick - ( ulReloadValue - portNVIC_SYSTICK_CURRENT_VALUE_REG );
|
||||
count reloaded with ulReloadValue. Reset the
|
||||
portNVIC_SYSTICK_LOAD_REG with whatever remains of this tick
|
||||
period. */
|
||||
portNVIC_SYSTICK_LOAD_REG = ( ulTimerCountsForOneTick - 1UL ) - ( ulReloadValue - portNVIC_SYSTICK_CURRENT_VALUE_REG );
|
||||
|
||||
/* The tick interrupt handler will already have pended the tick
|
||||
processing in the kernel. As the pending tick will be
|
||||
@ -399,16 +400,18 @@ void xPortSysTickHandler( void )
|
||||
else
|
||||
{
|
||||
/* Something other than the tick interrupt ended the sleep.
|
||||
Work out how long the sleep lasted. */
|
||||
ulCompletedSysTickIncrements = ( xExpectedIdleTime * ulTimerReloadValueForOneTick ) - portNVIC_SYSTICK_CURRENT_VALUE_REG;
|
||||
Work out how long the sleep lasted rounded to complete tick
|
||||
periods (not the ulReload value which accounted for part
|
||||
ticks). */
|
||||
ulCompletedSysTickDecrements = ( xExpectedIdleTime * ulTimerCountsForOneTick ) - portNVIC_SYSTICK_CURRENT_VALUE_REG;
|
||||
|
||||
/* How many complete tick periods passed while the processor
|
||||
was waiting? */
|
||||
ulCompleteTickPeriods = ulCompletedSysTickIncrements / ulTimerReloadValueForOneTick;
|
||||
ulCompleteTickPeriods = ulCompletedSysTickDecrements / ulTimerCountsForOneTick;
|
||||
|
||||
/* The reload value is set to whatever fraction of a single tick
|
||||
period remains. */
|
||||
portNVIC_SYSTICK_LOAD_REG = ( ( ulCompleteTickPeriods + 1 ) * ulTimerReloadValueForOneTick ) - ulCompletedSysTickIncrements;
|
||||
portNVIC_SYSTICK_LOAD_REG = ( ( ulCompleteTickPeriods + 1 ) * ulTimerCountsForOneTick ) - ulCompletedSysTickDecrements;
|
||||
}
|
||||
|
||||
/* Restart SysTick so it runs from portNVIC_SYSTICK_LOAD_REG
|
||||
@ -418,6 +421,10 @@ void xPortSysTickHandler( void )
|
||||
portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT | portNVIC_SYSTICK_ENABLE_BIT;
|
||||
|
||||
vTaskStepTick( ulCompleteTickPeriods );
|
||||
|
||||
/* The counter must start by the time the reload value is reset. */
|
||||
configASSERT( portNVIC_SYSTICK_CURRENT_VALUE_REG );
|
||||
portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;
|
||||
}
|
||||
}
|
||||
|
||||
@ -433,9 +440,9 @@ __weak void vPortSetupTimerInterrupt( void )
|
||||
/* Calculate the constants required to configure the tick interrupt. */
|
||||
#if configUSE_TICKLESS_IDLE == 1
|
||||
{
|
||||
ulTimerReloadValueForOneTick = ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ ) - 1UL;
|
||||
xMaximumPossibleSuppressedTicks = 0xffffffUL / ( ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ ) - 1UL );
|
||||
ulStoppedTimerCompensation = 45UL / ( configCPU_CLOCK_HZ / configSYSTICK_CLOCK_HZ );
|
||||
ulTimerCountsForOneTick = ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ );
|
||||
xMaximumPossibleSuppressedTicks = portMAX_24_BIT_NUMBER / ulTimerCountsForOneTick;
|
||||
ulStoppedTimerCompensation = portMISSED_COUNTS_FACTOR / ( configCPU_CLOCK_HZ / configSYSTICK_CLOCK_HZ );
|
||||
}
|
||||
#endif /* configUSE_TICKLESS_IDLE */
|
||||
|
||||
|
||||
@ -114,8 +114,8 @@ is defined. */
|
||||
#define portNVIC_PENDSVCLEAR_BIT ( 1UL << 27UL )
|
||||
#define portNVIC_PEND_SYSTICK_CLEAR_BIT ( 1UL << 25UL )
|
||||
|
||||
#define portNVIC_PENDSV_PRI ( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 16 )
|
||||
#define portNVIC_SYSTICK_PRI ( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 24 )
|
||||
#define portNVIC_PENDSV_PRI ( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 16UL )
|
||||
#define portNVIC_SYSTICK_PRI ( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 24UL )
|
||||
|
||||
/* Constants required to set up the initial stack. */
|
||||
#define portINITIAL_XPSR ( 0x01000000 )
|
||||
@ -123,6 +123,14 @@ is defined. */
|
||||
/* Constants used with memory barrier intrinsics. */
|
||||
#define portSY_FULL_READ_WRITE ( 15 )
|
||||
|
||||
/* The systick is a 24-bit counter. */
|
||||
#define portMAX_24_BIT_NUMBER ( 0xffffffUL )
|
||||
|
||||
/* A fiddle factor to estimate the number of SysTick counts that would have
|
||||
occurred while the SysTick counter is stopped during tickless idle
|
||||
calculations. */
|
||||
#define portMISSED_COUNTS_FACTOR ( 45UL )
|
||||
|
||||
/* Each task maintains its own interrupt status in the critical nesting
|
||||
variable. */
|
||||
static unsigned portBASE_TYPE uxCriticalNesting = 0xaaaaaaaa;
|
||||
@ -152,8 +160,8 @@ static void prvStartFirstTask( void );
|
||||
* The number of SysTick increments that make up one tick period.
|
||||
*/
|
||||
#if configUSE_TICKLESS_IDLE == 1
|
||||
static unsigned long ulTimerReloadValueForOneTick = 0;
|
||||
#endif
|
||||
static unsigned long ulTimerCountsForOneTick = 0;
|
||||
#endif /* configUSE_TICKLESS_IDLE */
|
||||
|
||||
/*
|
||||
* The maximum number of tick periods that can be suppressed is limited by the
|
||||
@ -233,7 +241,7 @@ __asm void prvStartFirstTask( void )
|
||||
*/
|
||||
portBASE_TYPE xPortStartScheduler( void )
|
||||
{
|
||||
/* Make PendSV, CallSV and SysTick the same priority as the kernel. */
|
||||
/* Make PendSV and SysTick the lowest priority interrupts. */
|
||||
portNVIC_SYSPRI2_REG |= portNVIC_PENDSV_PRI;
|
||||
portNVIC_SYSPRI2_REG |= portNVIC_SYSTICK_PRI;
|
||||
|
||||
@ -325,19 +333,17 @@ __asm void xPortPendSVHandler( void )
|
||||
|
||||
void xPortSysTickHandler( void )
|
||||
{
|
||||
/* Only reset the systick load register if configUSE_TICKLESS_IDLE is set to
|
||||
1. If it is set to 0 tickless idle is not being used. If it is set to a
|
||||
value other than 0 or 1 then a timer other than the SysTick is being used
|
||||
to generate the tick interrupt. */
|
||||
#if configUSE_TICKLESS_IDLE == 1
|
||||
portNVIC_SYSTICK_LOAD_REG = ulTimerReloadValueForOneTick;
|
||||
#endif
|
||||
|
||||
/* The SysTick runs at the lowest interrupt priority, so when this interrupt
|
||||
executes all interrupts must be unmasked. There is therefore no need to
|
||||
save and then restore the interrupt mask value as its value is already
|
||||
known. */
|
||||
( void ) portSET_INTERRUPT_MASK_FROM_ISR();
|
||||
{
|
||||
/* Increment the RTOS tick. */
|
||||
if( xTaskIncrementTick() != pdFALSE )
|
||||
{
|
||||
/* Pend a context switch. */
|
||||
/* A context switch is required. Context switching is performed in
|
||||
the PendSV interrupt. Pend the PendSV interrupt. */
|
||||
portNVIC_INT_CTRL_REG = portNVIC_PENDSVSET_BIT;
|
||||
}
|
||||
}
|
||||
@ -349,7 +355,7 @@ void xPortSysTickHandler( void )
|
||||
|
||||
__weak void vPortSuppressTicksAndSleep( portTickType xExpectedIdleTime )
|
||||
{
|
||||
unsigned long ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickIncrements;
|
||||
unsigned long ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickDecrements;
|
||||
portTickType xModifiableIdleTime;
|
||||
|
||||
/* Make sure the SysTick reload value does not overflow the counter. */
|
||||
@ -358,25 +364,20 @@ void xPortSysTickHandler( void )
|
||||
xExpectedIdleTime = xMaximumPossibleSuppressedTicks;
|
||||
}
|
||||
|
||||
/* Calculate the reload value required to wait xExpectedIdleTime
|
||||
tick periods. -1 is used because this code will execute part way
|
||||
through one of the tick periods, and the fraction of a tick period is
|
||||
accounted for later. */
|
||||
ulReloadValue = ( ulTimerReloadValueForOneTick * ( xExpectedIdleTime - 1UL ) );
|
||||
if( ulReloadValue > ulStoppedTimerCompensation )
|
||||
{
|
||||
ulReloadValue -= ulStoppedTimerCompensation;
|
||||
}
|
||||
|
||||
/* Stop the SysTick momentarily. The time the SysTick is stopped for
|
||||
is accounted for as best it can be, but using the tickless mode will
|
||||
inevitably result in some tiny drift of the time maintained by the
|
||||
kernel with respect to calendar time. */
|
||||
portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT;
|
||||
|
||||
/* Adjust the reload value to take into account that the current
|
||||
time slice is already partially complete. */
|
||||
ulReloadValue += ( portNVIC_SYSTICK_LOAD_REG - ( portNVIC_SYSTICK_LOAD_REG - portNVIC_SYSTICK_CURRENT_VALUE_REG ) );
|
||||
/* Calculate the reload value required to wait xExpectedIdleTime
|
||||
tick periods. -1 is used because this code will execute part way
|
||||
through one of the tick periods. */
|
||||
ulReloadValue = portNVIC_SYSTICK_CURRENT_VALUE_REG + ( ulTimerCountsForOneTick * ( xExpectedIdleTime - 1UL ) );
|
||||
if( ulReloadValue > ulStoppedTimerCompensation )
|
||||
{
|
||||
ulReloadValue -= ulStoppedTimerCompensation;
|
||||
}
|
||||
|
||||
/* Enter a critical section but don't use the taskENTER_CRITICAL()
|
||||
method as that will mask interrupts that should exit sleep mode. */
|
||||
@ -433,10 +434,10 @@ void xPortSysTickHandler( void )
|
||||
if( ( portNVIC_SYSTICK_CTRL_REG & portNVIC_SYSTICK_COUNT_FLAG_BIT ) != 0 )
|
||||
{
|
||||
/* The tick interrupt has already executed, and the SysTick
|
||||
count reloaded with the portNVIC_SYSTICK_LOAD_REG value.
|
||||
Reset the portNVIC_SYSTICK_LOAD_REG with whatever remains of
|
||||
this tick period. */
|
||||
portNVIC_SYSTICK_LOAD_REG = ulTimerReloadValueForOneTick - ( ulReloadValue - portNVIC_SYSTICK_CURRENT_VALUE_REG );
|
||||
count reloaded with ulReloadValue. Reset the
|
||||
portNVIC_SYSTICK_LOAD_REG with whatever remains of this tick
|
||||
period. */
|
||||
portNVIC_SYSTICK_LOAD_REG = ( ulTimerCountsForOneTick - 1UL ) - ( ulReloadValue - portNVIC_SYSTICK_CURRENT_VALUE_REG );
|
||||
|
||||
/* The tick interrupt handler will already have pended the tick
|
||||
processing in the kernel. As the pending tick will be
|
||||
@ -448,16 +449,18 @@ void xPortSysTickHandler( void )
|
||||
else
|
||||
{
|
||||
/* Something other than the tick interrupt ended the sleep.
|
||||
Work out how long the sleep lasted. */
|
||||
ulCompletedSysTickIncrements = ( xExpectedIdleTime * ulTimerReloadValueForOneTick ) - portNVIC_SYSTICK_CURRENT_VALUE_REG;
|
||||
Work out how long the sleep lasted rounded to complete tick
|
||||
periods (not the ulReload value which accounted for part
|
||||
ticks). */
|
||||
ulCompletedSysTickDecrements = ( xExpectedIdleTime * ulTimerCountsForOneTick ) - portNVIC_SYSTICK_CURRENT_VALUE_REG;
|
||||
|
||||
/* How many complete tick periods passed while the processor
|
||||
was waiting? */
|
||||
ulCompleteTickPeriods = ulCompletedSysTickIncrements / ulTimerReloadValueForOneTick;
|
||||
ulCompleteTickPeriods = ulCompletedSysTickDecrements / ulTimerCountsForOneTick;
|
||||
|
||||
/* The reload value is set to whatever fraction of a single tick
|
||||
period remains. */
|
||||
portNVIC_SYSTICK_LOAD_REG = ( ( ulCompleteTickPeriods + 1 ) * ulTimerReloadValueForOneTick ) - ulCompletedSysTickIncrements;
|
||||
portNVIC_SYSTICK_LOAD_REG = ( ( ulCompleteTickPeriods + 1 ) * ulTimerCountsForOneTick ) - ulCompletedSysTickDecrements;
|
||||
}
|
||||
|
||||
/* Restart SysTick so it runs from portNVIC_SYSTICK_LOAD_REG
|
||||
@ -467,6 +470,10 @@ void xPortSysTickHandler( void )
|
||||
portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT | portNVIC_SYSTICK_ENABLE_BIT;
|
||||
|
||||
vTaskStepTick( ulCompleteTickPeriods );
|
||||
|
||||
/* The counter must start by the time the reload value is reset. */
|
||||
configASSERT( portNVIC_SYSTICK_CURRENT_VALUE_REG );
|
||||
portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;
|
||||
}
|
||||
}
|
||||
|
||||
@ -485,9 +492,9 @@ void xPortSysTickHandler( void )
|
||||
/* Calculate the constants required to configure the tick interrupt. */
|
||||
#if configUSE_TICKLESS_IDLE == 1
|
||||
{
|
||||
ulTimerReloadValueForOneTick = ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ ) - 1UL;
|
||||
xMaximumPossibleSuppressedTicks = 0xffffffUL / ( ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ ) - 1UL );
|
||||
ulStoppedTimerCompensation = 45UL / ( configCPU_CLOCK_HZ / configSYSTICK_CLOCK_HZ );
|
||||
ulTimerCountsForOneTick = ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ );
|
||||
xMaximumPossibleSuppressedTicks = portMAX_24_BIT_NUMBER / ulTimerCountsForOneTick;
|
||||
ulStoppedTimerCompensation = portMISSED_COUNTS_FACTOR / ( configCPU_CLOCK_HZ / configSYSTICK_CLOCK_HZ );
|
||||
}
|
||||
#endif /* configUSE_TICKLESS_IDLE */
|
||||
|
||||
|
||||
@ -114,8 +114,8 @@ is defined. */
|
||||
#define portNVIC_PENDSVCLEAR_BIT ( 1UL << 27UL )
|
||||
#define portNVIC_PEND_SYSTICK_CLEAR_BIT ( 1UL << 25UL )
|
||||
|
||||
#define portNVIC_PENDSV_PRI ( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 16 )
|
||||
#define portNVIC_SYSTICK_PRI ( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 24 )
|
||||
#define portNVIC_PENDSV_PRI ( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 16UL )
|
||||
#define portNVIC_SYSTICK_PRI ( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 24UL )
|
||||
|
||||
/* Constants required to manipulate the VFP. */
|
||||
#define portFPCCR ( ( volatile unsigned long * ) 0xe000ef34 ) /* Floating point context control register. */
|
||||
@ -128,6 +128,14 @@ is defined. */
|
||||
/* Constants used with memory barrier intrinsics. */
|
||||
#define portSY_FULL_READ_WRITE ( 15 )
|
||||
|
||||
/* The systick is a 24-bit counter. */
|
||||
#define portMAX_24_BIT_NUMBER ( 0xffffffUL )
|
||||
|
||||
/* A fiddle factor to estimate the number of SysTick counts that would have
|
||||
occurred while the SysTick counter is stopped during tickless idle
|
||||
calculations. */
|
||||
#define portMISSED_COUNTS_FACTOR ( 45UL )
|
||||
|
||||
/* Each task maintains its own interrupt status in the critical nesting
|
||||
variable. */
|
||||
static unsigned portBASE_TYPE uxCriticalNesting = 0xaaaaaaaa;
|
||||
@ -161,8 +169,8 @@ static void prvEnableVFP( void );
|
||||
* The number of SysTick increments that make up one tick period.
|
||||
*/
|
||||
#if configUSE_TICKLESS_IDLE == 1
|
||||
static unsigned long ulTimerReloadValueForOneTick = 0;
|
||||
#endif
|
||||
static unsigned long ulTimerCountsForOneTick = 0;
|
||||
#endif /* configUSE_TICKLESS_IDLE */
|
||||
|
||||
/*
|
||||
* The maximum number of tick periods that can be suppressed is limited by the
|
||||
@ -271,7 +279,7 @@ __asm void prvEnableVFP( void )
|
||||
*/
|
||||
portBASE_TYPE xPortStartScheduler( void )
|
||||
{
|
||||
/* Make PendSV, CallSV and SysTick the same priroity as the kernel. */
|
||||
/* Make PendSV and SysTick the lowest priority interrupts. */
|
||||
portNVIC_SYSPRI2_REG |= portNVIC_PENDSV_PRI;
|
||||
portNVIC_SYSPRI2_REG |= portNVIC_SYSTICK_PRI;
|
||||
|
||||
@ -388,19 +396,17 @@ __asm void xPortPendSVHandler( void )
|
||||
|
||||
void xPortSysTickHandler( void )
|
||||
{
|
||||
/* Only reset the systick load register if configUSE_TICKLESS_IDLE is set to
|
||||
1. If it is set to 0 tickless idle is not being used. If it is set to a
|
||||
value other than 0 or 1 then a timer other than the SysTick is being used
|
||||
to generate the tick interrupt. */
|
||||
#if configUSE_TICKLESS_IDLE == 1
|
||||
portNVIC_SYSTICK_LOAD_REG = ulTimerReloadValueForOneTick;
|
||||
#endif
|
||||
|
||||
/* The SysTick runs at the lowest interrupt priority, so when this interrupt
|
||||
executes all interrupts must be unmasked. There is therefore no need to
|
||||
save and then restore the interrupt mask value as its value is already
|
||||
known. */
|
||||
( void ) portSET_INTERRUPT_MASK_FROM_ISR();
|
||||
{
|
||||
/* Increment the RTOS tick. */
|
||||
if( xTaskIncrementTick() != pdFALSE )
|
||||
{
|
||||
/* Pend a context switch. */
|
||||
/* A context switch is required. Context switching is performed in
|
||||
the PendSV interrupt. Pend the PendSV interrupt. */
|
||||
portNVIC_INT_CTRL_REG = portNVIC_PENDSVSET_BIT;
|
||||
}
|
||||
}
|
||||
@ -412,7 +418,7 @@ void xPortSysTickHandler( void )
|
||||
|
||||
__weak void vPortSuppressTicksAndSleep( portTickType xExpectedIdleTime )
|
||||
{
|
||||
unsigned long ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickIncrements;
|
||||
unsigned long ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickDecrements;
|
||||
portTickType xModifiableIdleTime;
|
||||
|
||||
/* Make sure the SysTick reload value does not overflow the counter. */
|
||||
@ -421,25 +427,20 @@ void xPortSysTickHandler( void )
|
||||
xExpectedIdleTime = xMaximumPossibleSuppressedTicks;
|
||||
}
|
||||
|
||||
/* Calculate the reload value required to wait xExpectedIdleTime
|
||||
tick periods. -1 is used because this code will execute part way
|
||||
through one of the tick periods, and the fraction of a tick period is
|
||||
accounted for later. */
|
||||
ulReloadValue = ( ulTimerReloadValueForOneTick * ( xExpectedIdleTime - 1UL ) );
|
||||
if( ulReloadValue > ulStoppedTimerCompensation )
|
||||
{
|
||||
ulReloadValue -= ulStoppedTimerCompensation;
|
||||
}
|
||||
|
||||
/* Stop the SysTick momentarily. The time the SysTick is stopped for
|
||||
is accounted for as best it can be, but using the tickless mode will
|
||||
inevitably result in some tiny drift of the time maintained by the
|
||||
kernel with respect to calendar time. */
|
||||
portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT;
|
||||
|
||||
/* Adjust the reload value to take into account that the current
|
||||
time slice is already partially complete. */
|
||||
ulReloadValue += ( portNVIC_SYSTICK_LOAD_REG - ( portNVIC_SYSTICK_LOAD_REG - portNVIC_SYSTICK_CURRENT_VALUE_REG ) );
|
||||
/* Calculate the reload value required to wait xExpectedIdleTime
|
||||
tick periods. -1 is used because this code will execute part way
|
||||
through one of the tick periods. */
|
||||
ulReloadValue = portNVIC_SYSTICK_CURRENT_VALUE_REG + ( ulTimerCountsForOneTick * ( xExpectedIdleTime - 1UL ) );
|
||||
if( ulReloadValue > ulStoppedTimerCompensation )
|
||||
{
|
||||
ulReloadValue -= ulStoppedTimerCompensation;
|
||||
}
|
||||
|
||||
/* Enter a critical section but don't use the taskENTER_CRITICAL()
|
||||
method as that will mask interrupts that should exit sleep mode. */
|
||||
@ -496,10 +497,10 @@ void xPortSysTickHandler( void )
|
||||
if( ( portNVIC_SYSTICK_CTRL_REG & portNVIC_SYSTICK_COUNT_FLAG_BIT ) != 0 )
|
||||
{
|
||||
/* The tick interrupt has already executed, and the SysTick
|
||||
count reloaded with the portNVIC_SYSTICK_LOAD_REG value.
|
||||
Reset the portNVIC_SYSTICK_LOAD_REG with whatever remains of
|
||||
this tick period. */
|
||||
portNVIC_SYSTICK_LOAD_REG = ulTimerReloadValueForOneTick - ( ulReloadValue - portNVIC_SYSTICK_CURRENT_VALUE_REG );
|
||||
count reloaded with ulReloadValue. Reset the
|
||||
portNVIC_SYSTICK_LOAD_REG with whatever remains of this tick
|
||||
period. */
|
||||
portNVIC_SYSTICK_LOAD_REG = ( ulTimerCountsForOneTick - 1UL ) - ( ulReloadValue - portNVIC_SYSTICK_CURRENT_VALUE_REG );
|
||||
|
||||
/* The tick interrupt handler will already have pended the tick
|
||||
processing in the kernel. As the pending tick will be
|
||||
@ -511,16 +512,18 @@ void xPortSysTickHandler( void )
|
||||
else
|
||||
{
|
||||
/* Something other than the tick interrupt ended the sleep.
|
||||
Work out how long the sleep lasted. */
|
||||
ulCompletedSysTickIncrements = ( xExpectedIdleTime * ulTimerReloadValueForOneTick ) - portNVIC_SYSTICK_CURRENT_VALUE_REG;
|
||||
Work out how long the sleep lasted rounded to complete tick
|
||||
periods (not the ulReload value which accounted for part
|
||||
ticks). */
|
||||
ulCompletedSysTickDecrements = ( xExpectedIdleTime * ulTimerCountsForOneTick ) - portNVIC_SYSTICK_CURRENT_VALUE_REG;
|
||||
|
||||
/* How many complete tick periods passed while the processor
|
||||
was waiting? */
|
||||
ulCompleteTickPeriods = ulCompletedSysTickIncrements / ulTimerReloadValueForOneTick;
|
||||
ulCompleteTickPeriods = ulCompletedSysTickDecrements / ulTimerCountsForOneTick;
|
||||
|
||||
/* The reload value is set to whatever fraction of a single tick
|
||||
period remains. */
|
||||
portNVIC_SYSTICK_LOAD_REG = ( ( ulCompleteTickPeriods + 1 ) * ulTimerReloadValueForOneTick ) - ulCompletedSysTickIncrements;
|
||||
portNVIC_SYSTICK_LOAD_REG = ( ( ulCompleteTickPeriods + 1 ) * ulTimerCountsForOneTick ) - ulCompletedSysTickDecrements;
|
||||
}
|
||||
|
||||
/* Restart SysTick so it runs from portNVIC_SYSTICK_LOAD_REG
|
||||
@ -530,6 +533,10 @@ void xPortSysTickHandler( void )
|
||||
portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT | portNVIC_SYSTICK_ENABLE_BIT;
|
||||
|
||||
vTaskStepTick( ulCompleteTickPeriods );
|
||||
|
||||
/* The counter must start by the time the reload value is reset. */
|
||||
configASSERT( portNVIC_SYSTICK_CURRENT_VALUE_REG );
|
||||
portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;
|
||||
}
|
||||
}
|
||||
|
||||
@ -548,9 +555,9 @@ void xPortSysTickHandler( void )
|
||||
/* Calculate the constants required to configure the tick interrupt. */
|
||||
#if configUSE_TICKLESS_IDLE == 1
|
||||
{
|
||||
ulTimerReloadValueForOneTick = ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ ) - 1UL;
|
||||
xMaximumPossibleSuppressedTicks = 0xffffffUL / ( ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ ) - 1UL );
|
||||
ulStoppedTimerCompensation = 45UL / ( configCPU_CLOCK_HZ / configSYSTICK_CLOCK_HZ );
|
||||
ulTimerCountsForOneTick = ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ );
|
||||
xMaximumPossibleSuppressedTicks = portMAX_24_BIT_NUMBER / ulTimerCountsForOneTick;
|
||||
ulStoppedTimerCompensation = portMISSED_COUNTS_FACTOR / ( configCPU_CLOCK_HZ / configSYSTICK_CLOCK_HZ );
|
||||
}
|
||||
#endif /* configUSE_TICKLESS_IDLE */
|
||||
|
||||
|
||||
Reference in New Issue
Block a user