Z86E3016PSG Datasheet, PDF (343/348 Pages) Zilog, Inc. – Z86E3016PSG

Z8 CPU
User Manual
325
Watch-Dog Timer
WDT
Instruction Format
OPC
Cycles
6
OPC
(Hex)
5F
Operation
The WDT (Watch–Dog Timer) is a retriggerable one shot timer that will
reset the Z8^® CPU if it reaches its terminal count. The WDT is initially
enabled by executing the WDT instruction. Each subsequent execution of
the WDT instruction refreshes the timer and prevents the WDT from tim-
ing out.
Flag
Z
S
V
D
H
Description
Undefined
Undefined
Undefined
Unaffected
Unaffected
Note: The WDT 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:
WDT
Op Code: .BYTE 5Fh
refreshes the Watch–Dog Timer.
UM001602-0904
Instruction Description