ulTaskGetIdleRunTimeCounter() function

configGENERATE_RUN_TIME_STATS, configUSE_STATS_FORMATTING_FUNCTIONS and INCLUDE_xTaskGetIdleTaskHandle must all be defined as 1 for these functions to be available. The application must also then provide definitions for portCONFIGURE_TIMER_FOR_RUN_TIME_STATS() and portGET_RUN_TIME_COUNTER_VALUE() to configure a peripheral timer/counter and return the timers current count value respectively. The counter should be at least 10 times the frequency of the tick count. Setting configGENERATE_RUN_TIME_STATS to 1 will result in a total accumulated execution time being stored for each task. The resolution of the accumulated time value depends on the frequency of the timer configured by the portCONFIGURE_TIMER_FOR_RUN_TIME_STATS() macro. While uxTaskGetSystemState() and vTaskGetRunTimeStats() writes the total execution time of each task into a buffer, ulTaskGetIdleRunTimeCounter() returns the total execution time of just the idle task and ulTaskGetIdleRunTimePercent() returns the percentage of the CPU time used by just the idle task. Note the amount of idle time is only a good measure of the slack time in a system if there are no other tasks executing at the idle priority, tickless idle is not used, and configIDLE_SHOULD_YIELD is set to 0.