Z8F08200100KIT Zilog, Z8F08200100KIT Datasheet - Page 96

• Manufacturer Part Number: Z8F08200100KIT
• Description: DEV KIT FOR Z8 ENCORE 4K TO 8K
• Manufacturer: Zilog
• Series: Z8 Encore!®r
• Type: MCUr

Specifications of Z8F08200100KIT

• Contents: Evaluation Board, Cable, Power Supply, Software and Documentation
• Data Bus Width: 8 bit
• Interface Type: RS-485
• Silicon Manufacturer: Zilog
• Core Architecture: Z8 Encore
• Silicon Core Number: Z8F0822SJ020
• Silicon Family Name: XP F0822
• For Use With/related Products: Z8 Encore!™
• For Use With: 269-4661 - KIT ACC ETHERNET SMART CABLE
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: 269-3183

Watchdog Timer
Operation
PS022517-0508
Watchdog Timer (WDT) protects against corrupt or unreliable software, power faults, and
other system-level problems which can place the Z8 Encore! XP
into unsuitable operating states. It includes the following features:
•
•
•
WDT is a retriggerable one-shot timer that resets or interrupts the Z8 Encore! XP F0822
Series device when the WDT reaches its terminal count. It uses its own dedicated on-chip
RC oscillator as its clock source. The WDT has only two modes of operation—ON and
OFF. When enabled, it always counts and must be refreshed to prevent a time-out. An
enable is performed by executing the WDT instruction or by setting the
Bit. The
has not been executed.
The WDT is a 24-bit reloadable downcounter that uses three 8-bit registers in the
eZ8 CPU register space to set the reload value. The nominal WDT time-out period is
given by the following equation:
where the WDT reload value is the decimal value of the 24-bit value given by
{WDTU[7:0], WDTH[7:0], WDTL[7:0]} and the typical Watchdog Timer RC oscillator
frequency is 10 kHz. WDT cannot be refreshed once it reaches
Reload Value must not be set to values below
approximate time-out delays for minimum and maximum WDT reload values.
Table 47. Watchdog Timer Approximate Time-Out Delays
WDT Time-out Period (ms)
WDT Reload
Value
(Hex)
000004
FFFFFF
On-chip RC oscillator.
A selectable time-out response—Reset or Interrupt.
24-bit programmable time-out value.
WDT_AO
WDT Reload
Value
bit enables the WDT to operate all the time, even if a WDT instruction
16,777,215
(Decimal)
4
=
WDT Reload Value
-------------------------------------------------- -
Approximate Time-Out Delay
(with 10 kHz typical WDT Oscillator Frequency)
10
1677.5 s
Typical
400 μs
000004H
.
Z8 Encore! XP
Table 47
000002H
Product Specification
®
Description
Minimum time-out delay
Maximum time-out delay
provides information on
F0822 Series device
WDT_AO
®
. The WDT
F0822 Series
Watchdog Timer
Option
83