z8fmc16100 ZiLOG Semiconductor, z8fmc16100 Datasheet - Page 73

• Manufacturer Part Number: z8fmc16100
• Description: Z8 Encore Motor Control Flash Mcus
• Manufacturer: ZiLOG Semiconductor

Watchdog Timer
PS024611-0408
Operation
The Watchdog Timer (WDT) helps protect against corrupted or unreliable software and
other system-level problems which may place the Z8FMC16100 Series Flash MCU into
unsuitable operating states. The WDT includes the following features:
•
•
•
The WDT is a retriggerable one-shot timer that resets or interrupts the Z8FMC16100
Series Flash MCU when the WDT reaches its terminal count. The WDT uses its own
dedicated on-chip RC oscillator as its clock source. The WDT has only two modes of
operation—ON and OFF. Once enabled, it always counts and must be refreshed to prevent
a timeout. An enable can be performed by executing the WDT instruction or by setting the
WDT_AO
WDT instruction has not been executed.
To minimize power consumption, the RC oscillator can be disabled. The RC oscillator is
disabled by clearing the
is disabled, the WDT will not operate.
The WDT is a 16-bit reloadable downcounter that uses two 8-bit registers in the eZ8 CPU
register space to set the reload value. The nominal WDT timeout period is calculated by
the following equation:
where the WDT reload value is assigned by {
Watchdog Timer RC oscillator frequency is 10 kHz. You must consider system require-
ments while selecting the time out delay.
timeout delays for the default and maximum WDT reload values.
WDT Timeout Period (ms) =
On-chip RC oscillator
A selectable timeout response: Reset or System Exception
16-bit programmable timeout value
Option Bit. The
WDTEN
WDT_AO
bit in the
bit enables the WDT to operate all the time, even if a
WDT Reload Value
Oscillator Control
Table 39
10
WDTH[7:0]
provides information on approximate
Z8FMC16100 Series Flash MCU
,
WDTL[7:0]
Register. If the RC oscillator
Product Specification
} and the typical
Operation
61