Zilog Z8F0130 - Manual (Page 106)

eZ8
™
CPU Core
User Manual
UM012820-0810 ATM Instruction
91
ATM
Definition
Atomic Execution.
Syntax
ATM
Operation
This new eZ8 instruction blocks all interrupt and DMA requests during
execution of the next 3 instructions.
Description
The Atomic instruction forces the eZ8 CPU to execute the next 3 instruc-
tions as a single block (that is, atom) of operations. During execution of
these next 3 instructions, all interrupts and DMA requests are prevented.
This allows operations to be performed on multibyte registers and mem-
ory locations that could be changed or used by interrupts or DMA. One
example of potential use of the ATM instruction is during adjustment of
multibyte stack pointer value.
Flags
C Unaffected
Z Unaffected
S Unaffected
V Unaffected
D Unaffected
H Unaffected
MIE Unaffected