Z8F0223SJ005EG Zilog, Z8F0223SJ005EG Datasheet - Page 97

• Manufacturer Part Number: Z8F0223SJ005EG
• Description: IC ENCORE MCU FLASH 2K 28SOIC
• Manufacturer: Zilog
• Series: Encore!® XP®r

Specifications of Z8F0223SJ005EG

• 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: 22
• Program Memory Size: 2KB (2K x 8)
• Program Memory Type: FLASH
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 105°C
• Package / Case: 28-SOIC (7.5mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Other names: 269-4082; Z8F0223SJ005EG

Watchdog Timer
Operation
Table 57. Watchdog Timer Approximate Time-Out Delays
PS024314-0308
WDT Reload Value
FFFFFF
000004
(Hex)
The Watchdog Timer (WDT) protects against corrupt or unreliable software, power faults,
and other system-level problems which can place Z8 Encore! XP
into unsuitable operating states. The features of Watchdog Timer include:
•
•
•
The WDT is a retriggerable one-shot timer that resets or interrupts Z8 Encore! XP F0823
Series devices when the WDT reaches its terminal count. The Watchdog Timer uses a ded-
icated on-chip RC oscillator as its clock source. The Watchdog 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
Flash Option Bit. The
upon reset, even if a
The Watchdog Timer is a 24-bit reloadable down counter 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 Watchdog Timer RC oscillator
frequency is 10 kHz. The Watchdog 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.
On-chip RC oscillator
A selectable time-out response: reset or interrupt
24-bit programmable time-out value
WDT Time-out Period (ms)
WDT Reload Value
16,777,215
(Decimal)
4
WDT
WDT_AO
instruction has not been executed.
bit forces the Watchdog Timer to operate immediately
(with 10 kHz typical WDT oscillator frequency)
=
WDT Reload Value
------------------------------------------
28 minutes
Typical
400 µs
Approximate Time-Out Delay
WDT
10
instruction or by setting the WDT_AO
Z8 Encore! XP
000004H
Minimum time-out delay
Maximum time-out delay
Product Specification
®
.
F0823 Series devices
Table 57
Description
®
F0823 Series
Watchdog Timer
provides
000002H
.
87