General Description - LAPIS Semiconductor ML62Q1000 Series User Manual

10. Watchdog Timer

10.1 General Description

The watchdog timer (WDT) is equipped with the following functions and can detect the runaway state of program or the
undefined state of the CPU by generating an interrupt or reset when an abnormality occurs.
·
If the counter is not cleared for more than a certain time period in program operation and overflows, the WDT
interrupt is generated in the first overflow and the WDT reset in the second overflow (if the window function is
disabled).
·
If the counter is not cleared for more than a certain time period in program operation and overflow occurs, the WDT
reset is generated in the first overflow (if the window function is enabled).
·
If the counter is cleared in the unexpected time period, the WDT invalid clear reset is generated (if the window
function is enabled).
The window function refers to the function through which "the time period during which WDT counter clear is enabled"
= "the time period during which the window is opened" and
"the time period in which WDT counter clear is disabled" = "the time period in which the window is closed" can be set.
Interrupt, reset
CPU clock
WDT clock
(WDTCLK)
WDT counter
value
Overflow
period (T )
WOV
0
FEUL62Q1000
Program operation
(clear processing)
CPU
WDT cleared
Figure10-1 Watchdog Timer Overview (With the Window Function Disabled)
Count clear control
Mode control
Watchdog
Clearing
WDT reset generated
WDT interrupt
generated
(First overflow)
ML62Q1000 Series User's Manual
Chapter 10 Watchdog Timer
Overflow
(Interrupt/reset)
Invalid clear reset
timer
counter
Time
(Second overflow)
10-1