UM012811-0904
eZ8 CPU Instruction Set Description
eZ8 CPU
User Manual
68
ATM
Atomic Execution
ATM
Operation
Blocks all interrupt and DMA requests during execution of the next 3instructions.
Description
The Atomic instruction forces the eZ8 CPU to execute the next 3 instructions as a single
block (i.e. atom) of operations. During execution of these next 3 instructions, all interrupts
and DMA requests are prevented. This allows operations to be performed on multi-byte
registers and memory locations that could be changed or used by interrupts or the DMA.
One example of potential use of the ATM instruction is during adjustment of the multi-
byte stack pointer value.
Flags
Attributes
C
Unaffected.
Z
Unaffected.
S
Unaffected.
V
Unaffected.
D
Unaffected.
H
Unaffected.
MIE
Unaffected.
Mnemonic Destination, Source
Byte 1
Byte 2
Byte 3
Byte 4
ATM
—
2F
—
—
—