Z8F6422AR020SC2104 Zilog, Z8F6422AR020SC2104 Datasheet - Page 107

• Manufacturer Part Number: Z8F6422AR020SC2104
• Description: IC ENCORE MCU FLASH 64K 64LQFP
• Manufacturer: Zilog
• Series: Encore!® XP®r

Specifications of Z8F6422AR020SC2104

• Core Processor: Z8
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, IrDA, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, DMA, POR, PWM, WDT
• Number Of I /o: 46
• Program Memory Size: 64KB (64K x 8)
• Program Memory Type: FLASH
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Data Converters: A/D 12x10b
• Oscillator Type: Internal
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 64-LQFP
• For Use With: 269-4678 - KIT DEV FOR Z8F642 MCU 44 PIN269-4677 - KIT DEV FOR Z8F642 MCU 28PIN269-4540 - KIT DEV FOR Z8 ENCORE 16K TO 64K
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Other names: 269-3641

Watchdog Timer
Operation
PS019921-0308
The Watchdog Timer (WDT) helps protect against corrupt or unreliable software, power
faults, and other system-level problems which may place the Z8 Encore! XP into unsuit-
able operating states. The features of Watchdog Timer include:
•
•
•
•
The Watchdog Timer (WDT) is a retriggerable one-shot timer that resets or interrupts the
Z8 Encore! XP
Watchdog Timer uses its own dedicated on-chip RC oscillator as its clock source. The
Watchdog Timer has only two modes of operation—ON and OFF. Once enabled, it always
counts and must be refreshed to prevent a time-out. An enable can be performed by exe-
cuting the WDT instruction or by setting the WDT_AO Option Bit. The WDT_AO bit
enables the Watchdog Timer to operate all the time, even if a WDT instruction has not
been executed.
The Watchdog Timer is a 24-bit reloadable downcounter that uses three 8-bit registers in
the eZ8
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. The Watchdog Timer cannot be refreshed once it reaches
The WDT Reload Value must not be set to values below
information on approximate time-out delays for the minimum and maximum WDT reload
values.
On-chip RC oscillator.
A selectable time-out response.
WDT Time-out response: Reset or interrupt.
24-bit programmable time-out value.
™
CPU register space to set the reload value. The nominal WDT time-out period is
WDT Time-out Period (ms)
®
F64XX Series devices when the WDT reaches its terminal count. The
=
WDT Reload Value
----------------------------------------------- -
10
Z8 Encore! XP
000004H
Product Specification
.
Table 47
®
F64XX Series
Watchdog Timer
provides
000002H
.
93