Datasheet

102
11011B–ATARM–21-Feb-12
SAM3N
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 84.
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 match-
ing store exclusive instruction in a synchronization operation.
See “Synchronization primitives” on page 61 for more information.
10.12.9.3 Condition flags
These instructions do not change the flags.
10.12.9.4 Examples
CLREX