2.6.4.8.1 Syntax

LDREX{cond} Rt, [Rn {, #offset}]
STREX{cond} Rd, Rt, [Rn {, #offset}]
LDREXB{cond} Rt, [Rn]
STREXB{cond} Rd, Rt, [Rn]
LDREXH{cond} Rt, [Rn]
STREXH{cond} Rd, Rt, [Rn]

where:

cond is an optional condition code, see 2.6.3.7 Conditional Execution.

Rd is the destination register for the returned status.

Rt is the register to load or store.

Rn is the register on which the memory address is based.

offset is an optional offset applied to the value in Rn. If offset is omitted, the address is the value in Rn.