Datasheet

SAM3X / SAM3A [DATASHEET]
Atmel-11057C-ATARM-SAM3X-SAM3A-Datasheet_23-Mar-15
108
10.12.9 CLREX
Clear Exclusive.
10.12.9.1 Syntax
CLREX{cond}
where:
cond is an optional condition code, see “Conditional execution” on page 91.
10.12.9.2 Operation
Use CLREX to make the next STREX, STREXB, or STREXH instruction write 1 to its destination register and fail to
perform the store. It is useful in exception handler code to force the failure of the store exclusive if the exception
occurs between a load exclusive instruction and the matching store exclusive instruction in a synchronization
operation.
See “Synchronization primitives” on page 69 for more information.
10.12.9.3 Condition flags
These instructions do not change the flags.
10.12.9.4 Examples
CLREX