[Event Group API]
const EventBits_t uxBitsToClear );
A version of xEventGroupClearBits() that
can be called from an interrupt. The clear operation is deferred to the RTOS
daemon task – which is also known as the timer service task. The priority of the
daemon task is set by the
setting in FreeRTOSConfig.h.
The RTOS source file FreeRTOS/source/event_groups.c must be
included in the build for the xEventGroupClearBitsFromISR() function to be available.
The event group in which the bits are to be cleared. The
event group must have previously been created using a call to
A bitwise value that indicates the bit or bits to clear
in the event group. For example set uxBitsToClear to 0x08 to
clear just bit 3. Set uxBitsToClear to 0x09 to clear bit 3
and bit 0.
pdPASS if the operation was successfully deferred to the RTOS daemon task. Otherwise pdFALSE. pdFALSE will only be returned if the timer command queue is full.
#define BIT_0 ( 1 << 0 )
#define BIT_4 ( 1 << 4 )
/* This code assumes the event group referenced by the
xEventGroup variable has already been created using a call to
void anInterruptHandler( void )
/* Clear bit 0 and bit 4 in xEventGroup. */
xSuccess = xEventGroupClearBitsFromISR(
xEventGroup, /* The event group being updated. */
BIT_0 | BIT_4 );/* The bits being cleared. */
if( xSuccess == pdPASS )
/* The command was sent to the daemon task. */
/* The clear bits command was not sent to the daemon task. */
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