2.2.3 Write Operation Lost if Consecutive Writes to Specific Address Spaces

An ST/STD/STS instruction to address ≥ 64 followed by either an ST/STD instruction to address < 64 or a write to the SLPCTRL.CTRLA register will cause a loss of the last write.

Work Around

To avoid loss of write operation, use one of the following workarounds depending on address space:

Insert an NOP instruction before writing to address < 64, or use the OUT instruction instead of ST/STD
Insert an NOP instruction before writing to SLPCTRL.CTRLA register

Affected Silicon Revisions


Rev. A0	Rev. A2	Rev. A4
X	X	X