Z8F083A0128ZCOG Zilog, Z8F083A0128ZCOG Datasheet - Page 99

• Manufacturer Part Number: Z8F083A0128ZCOG
• Description: KIT DEVELOPMENT F083A
• Manufacturer: Zilog
• Series: Z8 Encore! XP®r
• Type: MCUr

Specifications of Z8F083A0128ZCOG

• Contents: Hardware, Software and Documentation
• For Use With/related Products: Z8F083A
• For Use With: 269-4661 - KIT ACC ETHERNET SMART CABLE
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 269-4672

Watchdog Timer
Operation
PS026308-1207
The Watchdog Timer (WDT) protects from corrupted or unreliable software, power faults,
and other system-level problems, which may place the Z8 Encore! F083A Series devices
into unsuitable operating states. The Watchdog Timer includes the following features:
•
•
•
The WDT is a re-triggerable one-shot timer that resets or interrupts the Z8 Encore! F083A
Series devices when the WDT reaches its terminal count. The WDT uses a dedicated on-
chip RC oscillator as its clock source. The WDT operates only in two modes: ON and
OFF. Once enabled, it always counts and must be refreshed to prevent a time-out. Perform
an enable by executing the WDT instruction or by setting the WDT_AO Flash option bit.
The WDT_AO bit forces the WDT to operate immediately on reset, even if a WDT
instruction 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
calculated by the following equation:
where the WDT reload value is the 24-bit decimal value given by {WDTU[7:0],
WDTH[7:0], WDTL[7:0]} and the typical Watchdog Timer RC oscillator frequency is
10 kHz. The Watchdog Timer cannot be refreshed after it reaches
reload value must not be set to values below
information about approximate time-out delays for the minimum and maximum WDT
reload values.
WDT Time-out Period (ms)
On-chip RC oscillator.
A selectable time-out response: reset or interrupt.
24-bit programmable time-out value.
=
WDT Reload Value
------------------------------------------------- -
000004H
10
.
Table 55
Z8 Encore!
Product Specification
on page 88 provides
000002H
®
F083A Series
Watchdog Timer
. The WDT
87