xEventGroupClearBits

Collaboration diagram for xEventGroupClearBits:

event_groups.h

EventBits_t xEventGroupClearBits( EventGroupHandle_t xEventGroup, const EventBits_t uxBitsToClear );

Clear bits within an event group. This function cannot be called from an interrupt.

The configUSE_EVENT_GROUPS configuration constant must be set to 1 for xEventGroupClearBits() to be available.

Parameters

xEventGroup	The event group in which the bits are to be cleared.
uxBitsToClear	A bitwise value that indicates the bit or bits to clear in the event group. For example, to clear bit 3 only, set uxBitsToClear to 0x08. To clear bit 3 and bit 0 set uxBitsToClear to 0x09.

Returns

The value of the event group before the specified bits were cleared.

Example usage:

#define BIT_0 ( 1 << 0 )
#define BIT_4 ( 1 << 4 )
 
void aFunction( EventGroupHandle_t xEventGroup )
{
EventBits_t uxBits;
 
     // Clear bit 0 and bit 4 in xEventGroup.
     uxBits = xEventGroupClearBits(
                             xEventGroup,    // The event group being updated.
                             BIT_0 | BIT_4 );// The bits being cleared.
 
     if( ( uxBits & ( BIT_0 | BIT_4 ) ) == ( BIT_0 | BIT_4 ) )
     {
         // Both bit 0 and bit 4 were set before xEventGroupClearBits() was
         // called.  Both will now be clear (not set).
     }
     else if( ( uxBits & BIT_0 ) != 0 )
     {
         // Bit 0 was set before xEventGroupClearBits() was called.  It will
         // now be clear.
     }
     else if( ( uxBits & BIT_4 ) != 0 )
     {
         // Bit 4 was set before xEventGroupClearBits() was called.  It will
         // now be clear.
     }
     else
     {
         // Neither bit 0 nor bit 4 were set in the first place.
     }
}