z16f2811 ZiLOG Semiconductor, z16f2811 Datasheet - Page 250

• Manufacturer Part Number: z16f2811
• Description: High Performance Microcontrollers
• Manufacturer: ZiLOG Semiconductor

Table 119. Watchdog Timer Approximate Time-Out Delays
PS022006-0207
WDT Reload Value
Watchdog Timer Refresh
Watchdog Timer Time-Out Response
(Hex)
FFFF
0400
When enabled first, the WDT is loaded with the value in the Watchdog Timer Reload
registers. The WDT then counts down to
the ZNEO CPU. Execution of the
with the WDT Reload value stored in the Watchdog Timer Reload registers. Counting
resumes following the reload operation.
When the ZNEO Z16F Series device is operating in DEBUG mode (through the OCD),
the WDT is continuously refreshed to prevent spurious WDT time-outs.
The WDT times out when the counter reaches
either a system exception or a short reset. The
response of the WDT. For information on programming of the
Option Bits
WDT System Exception in Normal Operation
If configured to generate a system exception when a time-out occurs, the WDT issues an
exception request to the interrupt controller. The ZNEO CPU responds to the request by
fetching the System Exception vector and executing code from the vector address. After
time-out and system exception generation, the WDT is reloaded automatically and
continues counting.
WDT System Exception in STOP Mode
If configured to generate a system exception when a time-out occurs and the ZNEO Z16F
Series device is in STOP mode, the WDT automatically initiates a Stop Mode Recovery
and generates a system exception request. Both the WDT status bit and the STOP bit in the
Reset Status and Control Register
For detailed information, see
WDT Reload Value
on page 289.
(Decimal)
65,536
1024
P R E L I M I N A R Y
Reset and Stop Mode Recovery
WDT
are set to 1 following WDT time-out in STOP mode.
(with 10 kHz typical WDT oscillator frequency)
instruction causes the downcounter to be reloaded
0000H
102.4 ms
Typical
6.55 s
Approximate Time-Out Delay
WDT_RES
0000H
unless a
. A time-out of the WDT generates
option bit determines the time-out
WDT
on page 57.
instruction is executed by
WDT_RES
Description
Reset value time-out
delay
Maximum time-out delay
Product Specification
ZNEO
option bit, see
™
Watchdog Timer
Z16F Series
236