ML610Q111/ML610Q112 User’s Manual
Chapter 9 Watchdog Timer
FEUL610Q111
9-5
9.3 Description of Operation
The WDT counter starts counting by using a signal T256Hz of the low-speed time base counter, after the system reset has
been released and the low-speed clock oscillation start.
Write "5AH" when the internal pointer (WDP) is "0" and then the WDT counter is cleared by writing "0A5H" when WDP
is "1".
WDP is reset to “0” at the time of system reset or when the WDT counter overflows and is inverted whenever data is
written to WDTCON.
When the WDT counter cannot be cleared within the WDT counter overflow period (T
WOV
), a watchdog timer interrupt
(WDTINT) occurs. If the WDT counter is not cleared even by the software processing performed following the watchdog
timer interrupt and overflow occurs again, WDT reset occurs and the mode shifts to a system reset mode.
For the overflow period (T
WOV
) of the WDT counter, it is selectable from the following seven types of values by the
watchdog mode register (WDTMOD).
Clear the WDT counter within the clear period of the WDT counter shown in Table 9-1.
Table 9-1 Clear Period of WDT Counter
WDT2
WDT1
WDT0
T
WOV
T
WCL
0
0
0
125 ms
Approx. 121 ms
0
0
1
500 ms
Approx. 496 ms
0
1
0
2000 ms
Approx. 1996 ms
0
1
1
8000 ms
Approx. 7996 ms
1
0
0
23.4 ms
Approx. 19.4 ms
1
0
1
31.25 ms
Approx. 27.25 ms
1
1
0
62.5 ms
Approx. 58.5 ms
1
1
1
Prohibited
Prohibited
Note
:
- By the first overflow of the WDT counter, the watchdog timer interrupt occurs. And by the second overflow of the WDT
counter, the WDT reset occurs. In other words, the watchdog timer interrupt by the first overflow of WDT counter means a
warning. Please use WDT interrupt as processing to restart a system or to turn off a system safely.
- Even if a watchdog timer interrupt function is not used, a watch dog timer interrupt occurs. Therefore, be sure to define
the watch dog timer interrupt function.
Summary of Contents for ML610Q111
Page 1: ...ML610Q111 ML610Q112 User s Manual Issue Date Nov 16 2016 FEUL610Q111 05 ...
Page 14: ...Chapter 1 Overview ...
Page 26: ...Chapter 2 CPU and Memory Space ...
Page 34: ...Chapter 3 Reset Function ...
Page 38: ...Chapter 4 MCU Control Function ...
Page 53: ...Chapter 5 Interrupts INTs ...
Page 81: ...Chapter 6 Clock Generation Circuit ...
Page 95: ...Chapter 7 Time Base Counter ...
Page 103: ...Chapter 8 Timers ...
Page 145: ...Chapter 9 Watchdog Timer ...
Page 153: ...Chapter 10 PWM ...
Page 199: ...Chapter 11 Synchronous Serial Port ...
Page 212: ...Chapter 12 UART ...
Page 240: ...Chapter 13 I2 C Bus Interface Master ...
Page 254: ...Chapter 14 I2 C Bus Interface Slave ...
Page 269: ...Chapter 15 Port A ...
Page 279: ...Chapter 16 Port B ...
Page 291: ...Chapter 17 Port C ...
Page 303: ...Chapter 18 Port D ...
Page 312: ...Chapter 19 Port AB Interrupts ...
Page 317: ...Chapter 20 Successive Approximation Type A D Converter ...
Page 335: ...Chapter 21 Voltage Level Supervisor ...
Page 342: ...Chapter 22 Analog Comparator ...
Page 353: ...Chapter 23 Data Flash Memory ...
Page 373: ...Chapter 24 On chip Debug ...
Page 375: ...Appendixes ...
Page 393: ...Appendix E ...
Page 398: ...Revision History ...