+#if configUSE_TICKLESS_IDLE == 1\r
+\r
+ __weak void vPortSuppressTicksAndSleep( portTickType xExpectedIdleTime )\r
+ {\r
+ unsigned long ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickIncrements;\r
+ portTickType xModifiableIdleTime;\r
+\r
+ /* Make sure the SysTick reload value does not overflow the counter. */\r
+ if( xExpectedIdleTime > xMaximumPossibleSuppressedTicks )\r
+ {\r
+ xExpectedIdleTime = xMaximumPossibleSuppressedTicks;\r
+ }\r
+\r
+ /* Calculate the reload value required to wait xExpectedIdleTime\r
+ tick periods. -1 is used because this code will execute part way\r
+ through one of the tick periods, and the fraction of a tick period is\r
+ accounted for later. */\r
+ ulReloadValue = ( ulTimerReloadValueForOneTick * ( xExpectedIdleTime - 1UL ) );\r
+ if( ulReloadValue > ulStoppedTimerCompensation )\r
+ {\r
+ ulReloadValue -= ulStoppedTimerCompensation;\r
+ }\r
+\r
+ /* Stop the SysTick momentarily. The time the SysTick is stopped for\r
+ is accounted for as best it can be, but using the tickless mode will\r
+ inevitably result in some tiny drift of the time maintained by the\r
+ kernel with respect to calendar time. */\r
+ portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT;\r
+\r
+ /* Adjust the reload value to take into account that the current\r
+ time slice is already partially complete. */\r
+ ulReloadValue += ( portNVIC_SYSTICK_LOAD_REG - ( portNVIC_SYSTICK_LOAD_REG - portNVIC_SYSTICK_CURRENT_VALUE_REG ) );\r
+\r
+ /* Enter a critical section but don't use the taskENTER_CRITICAL()\r
+ method as that will mask interrupts that should exit sleep mode. */\r
+ __disable_irq();\r
+\r
+ /* If a context switch is pending or a task is waiting for the scheduler\r
+ to be unsuspended then abandon the low power entry. */\r
+ if( eTaskConfirmSleepModeStatus() == eAbortSleep )\r
+ {\r
+ /* Restart SysTick. */\r
+ portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT | portNVIC_SYSTICK_ENABLE_BIT;\r
+\r
+ /* Re-enable interrupts - see comments above __disable_irq() call\r
+ above. */\r
+ __enable_irq();\r
+ }\r
+ else\r
+ {\r
+ /* Set the new reload value. */\r
+ portNVIC_SYSTICK_LOAD_REG = ulReloadValue;\r
+\r
+ /* Clear the SysTick count flag and set the count value back to\r
+ zero. */\r
+ portNVIC_SYSTICK_CURRENT_VALUE_REG = 0UL;\r
+\r
+ /* Restart SysTick. */\r
+ portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT | portNVIC_SYSTICK_ENABLE_BIT;\r
+\r
+ /* Sleep until something happens. configPRE_SLEEP_PROCESSING() can\r
+ set its parameter to 0 to indicate that its implementation contains\r
+ its own wait for interrupt or wait for event instruction, and so wfi\r
+ should not be executed again. However, the original expected idle\r
+ time variable must remain unmodified, so a copy is taken. */\r
+ xModifiableIdleTime = xExpectedIdleTime;\r
+ configPRE_SLEEP_PROCESSING( xModifiableIdleTime );\r
+ if( xModifiableIdleTime > 0 )\r
+ {\r
+ __wfi();\r
+ __dsb( portSY_FULL_READ_WRITE );\r
+ __isb( portSY_FULL_READ_WRITE );\r
+ }\r
+ configPOST_SLEEP_PROCESSING( xExpectedIdleTime );\r
+\r
+ /* Stop SysTick. Again, the time the SysTick is stopped for is\r
+ accounted for as best it can be, but using the tickless mode will\r
+ inevitably result in some tiny drift of the time maintained by the\r
+ kernel with respect to calendar time. */\r
+ portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT;\r
+\r
+ /* Re-enable interrupts - see comments above __disable_irq() call\r
+ above. */\r
+ __enable_irq();\r
+\r
+ if( ( portNVIC_SYSTICK_CTRL_REG & portNVIC_SYSTICK_COUNT_FLAG_BIT ) != 0 )\r
+ {\r
+ /* The tick interrupt has already executed, and the SysTick\r
+ count reloaded with the portNVIC_SYSTICK_LOAD_REG value.\r
+ Reset the portNVIC_SYSTICK_LOAD_REG with whatever remains of\r
+ this tick period. */\r
+ portNVIC_SYSTICK_LOAD_REG = ulTimerReloadValueForOneTick - ( ulReloadValue - portNVIC_SYSTICK_CURRENT_VALUE_REG );\r
+\r
+ /* The tick interrupt handler will already have pended the tick\r
+ processing in the kernel. As the pending tick will be\r
+ processed as soon as this function exits, the tick value\r
+ maintained by the tick is stepped forward by one less than the\r
+ time spent waiting. */\r
+ ulCompleteTickPeriods = xExpectedIdleTime - 1UL;\r
+ }\r
+ else\r
+ {\r
+ /* Something other than the tick interrupt ended the sleep.\r
+ Work out how long the sleep lasted. */\r
+ ulCompletedSysTickIncrements = ( xExpectedIdleTime * ulTimerReloadValueForOneTick ) - portNVIC_SYSTICK_CURRENT_VALUE_REG;\r
+\r
+ /* How many complete tick periods passed while the processor\r
+ was waiting? */\r
+ ulCompleteTickPeriods = ulCompletedSysTickIncrements / ulTimerReloadValueForOneTick;\r
+\r
+ /* The reload value is set to whatever fraction of a single tick\r
+ period remains. */\r
+ portNVIC_SYSTICK_LOAD_REG = ( ( ulCompleteTickPeriods + 1 ) * ulTimerReloadValueForOneTick ) - ulCompletedSysTickIncrements;\r
+ }\r
+\r
+ /* Restart SysTick so it runs from portNVIC_SYSTICK_LOAD_REG\r
+ again, then set portNVIC_SYSTICK_LOAD_REG back to its standard\r
+ value. */\r
+ portNVIC_SYSTICK_CURRENT_VALUE_REG = 0UL;\r
+ portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT | portNVIC_SYSTICK_ENABLE_BIT;\r
+\r
+ vTaskStepTick( ulCompleteTickPeriods );\r
+ }\r
+ }\r
+\r
+#endif /* #if configUSE_TICKLESS_IDLE */\r
+\r
+/*-----------------------------------------------------------*/\r
+\r