Zilog Z86193 - Manual (Page 255)

Z8
®
CPU
User Manual
UM001604-0108 Instruction Description
248
Watchdog Timer
Syntax
WDT
Instruction Format
Operation
The WDT is a retriggerable one shot timer that resets 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 timing
out.
The WDT instruction should not be used following any instruction in which the condition of
the Flags is important.
Example 1
If the WDT is enabled, the statement:
WDT
Op Code: .BYTE 5Fh
refreshes the Watchdog Timer.
Example 2
The first execution of the statement:
WDT
Op Code: .BYTE 5Fh
enables the Watchdog Timer.
Cycles
OPC
(Hex)
OPC 6 5F
Flag Description
Z Undefined
S Undefined
V Undefined
D Unaffected
H Unaffected
Note: