Zilog Z86193 - Manual (Page 256)

Z8
®
CPU
User Manual
UM001604-0108 Instruction Description
249
Watchdog Timer Enable During Halt Mode
Syntax
WDh
Instruction Format
Operation
When this instruction is executed it enables the WDT during HALT mode. If this instruc-
tion is not executed the WDT stops when entering HALT mode. This instruction does not
clear the counter, it just makes it possible to have the WDT function running during HALT
mode. A WDh instruction executed without executing WDT (
5Fh
) has no effect.
The
WDh
instruction should not be used following any instruction in which the condition of
the Flags is important.
Example
If the WDT is enabled, the statement:
WDh
Op Code: .BYTE 4Fh
enables the WDT in HALT mode.
This instruction format is valid only for the Z86C04, Z86C08, Z86E04, Z86E07, and
Z86E08 MCUs.
Cycles
OPC
(Hex)
OPC 6 4F
Flag Description
Z Undefined
S Undefined
V Undefined
D Unaffected
H Unaffected
Note:
Note: