Z8F0813HJ005EG Zilog, Z8F0813HJ005EG Datasheet - Page 98

• Manufacturer Part Number: Z8F0813HJ005EG
• Description: IC Z8 ENCORE MCU FLASH 8K 28SSOP
• Manufacturer: Zilog
• Series: Encore!® XP®r

Specifications of Z8F0813HJ005EG

• Core Processor: Z8
• Core Size: 8-Bit
• Speed: 5MHz
• Connectivity: IrDA, UART/USART
• Peripherals: Brown-out Detect/Reset, LED, POR, PWM, WDT
• Number Of I /o: 24
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: FLASH
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 105°C
• Package / Case: 28-SSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -
• Other names: 269-4182; Z8F0813HJ005EG

Watch-Dog Timer
Overview
Operation
PS025203-0405
The Watch-Dog Timer (WDT) protects against corrupt or unreliable software, power
faults, and other system-level problems which may place the Z8 Encore!
devices into unsuitable operating states. The Watch-Dog Timer includes the following fea-
tures:
•
•
•
The Watch-Dog Timer (WDT) is a retriggerable one-shot timer that resets or interrupts the
Z8 Encore!
Watch-Dog Timer uses a dedicated on-chip RC oscillator as its clock source. The Watch-
Dog Timer operates in only 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 instruc-
tion or by setting the WDT_AO Flash Option Bit. The WDT_AO bit forces the Watch-
Dog Timer to operate immediately upon reset, even if a WDT instruction has not been
executed.
The Watch-Dog Timer 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
described 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 Watch-Dog Timer RC oscillator
frequency is 10KHz. The Watch-Dog Timer cannot be refreshed after it reaches
The WDT 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
®
Z8F0823 Series devices when the WDT reaches its terminal count. The
P R E L I M I N A R Y
=
WDT Reload Value
------------------------------------------------- -
10
Z8 Encore!
000004H
Product Specification
. Table 57 provides
®
®
Z8F0823 Series
Z8F0823 Series
Watch-Dog Timer
000002H
.
81