Z8F0412SJ020SG Zilog, Z8F0412SJ020SG Datasheet - Page 96

• Manufacturer Part Number: Z8F0412SJ020SG
• Description: IC ENCORE MCU FLASH 4K 28SOIC
• Manufacturer: Zilog
• Series: Encore!® XP®r

Specifications of Z8F0412SJ020SG

• Core Processor: Z8
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, IrDA, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 19
• Program Memory Size: 4KB (4K 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: 0°C ~ 70°C
• Package / Case: 28-SOIC (7.5mm Width)
• Processor Series: Z8F041xx
• Core: eZ8
• Data Bus Width: 8 bit
• Data Ram Size: 1 KB
• Interface Type: I2C, SPI, UART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 19
• Number Of Timers: 2
• Operating Supply Voltage: 2.7 V to 3.6 V
• Maximum Operating Temperature: + 70 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: 0 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -
• Lead Free Status / Rohs Status: Details
• Other names: 269-4107; Z8F0412SJ020SG

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