Z8F011ASH020EG2156 ZiLOG, Z8F011ASH020EG2156 Datasheet - Page 110

• Manufacturer Part Number: Z8F011ASH020EG2156
• Description: 8-bit Microcontrollers - MCU 1K FLASH 256B RAM 16B NVDS
• Manufacturer: ZiLOG

Specifications of Z8F011ASH020EG2156

• Rohs: yes
• Core: eZ8
• Data Bus Width: 8 bit
• Maximum Clock Frequency: 20 MHz
• Program Memory Size: 1 KB
• Data Ram Size: 256 B
• On-chip Adc: No
• Package / Case: SOIC-20
• Mounting Style: SMD/SMT
• Interface Type: UART
• Maximum Operating Temperature: + 105 C
• Minimum Operating Temperature: - 40 C
• Number Of Programmable I/os: 17
• Number Of Timers: 2
• Program Memory Type: Flash
• Supply Voltage - Max: 3.6 V
• Supply Voltage - Min: 2.7 V

Watchdog Timer
PS025113-1212
WDT Reload Value
Operation
FFFFFF
000004
000400
(Hex)
The Watchdog Timer (WDT) protects from corrupted or unreliable software, power faults
and other system-level problems which can place the Z8 Encore! F0830 Series devices
into unsuitable operating states. The features of the Watchdog Timer include:
•
•
•
The Watchdog Timer is a retriggerable one-shot timer that resets or interrupts the Z8
Encore! F0830 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 Watchdog 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
calculated using the following equation:
WDT Time-out Period (ms)
where the WDT reload value is the 24-bit decimal value provided 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
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
Table 58. Watchdog Timer Approximate Time-Out Delays
WDT Reload Value
16,777,215
(Decimal)
1024
4
=
WDT Reload Value
----------------------------------------------- -
(with 10 KHz Typical WDT Oscillator Frequency)
28 minutes
10
Typical
102 ms
400 µs
Approximate Time-Out Delay
000004H
. Table 58 provides information
Z8 Encore!
Minimum time-out delay
Default time-out delay
Maximum time-out delay
Product Specification
000002H
Description
®
Watchdog Timer
F0830 Series
. The WDT
92