
ML62Q1000 Series User's Manual
Chapter 10 Watchdog Timer
FEUL62Q1000
10-9
10.3 Description of Operation
The WDT counter starts counting up at the rising edge of the WDT counter operation clock (WDTCLK) chosen by the
code option when the system reset is released with operation enabled also by the code option.
The WDT counter can be cleared by writing "0x5A" to the WDTCON register with the WDP bit set to "0", then writing
"0xA5" to the WDTCON register with the WDP bit set to "1" while WDT counter clearing is enabled.
The WDP bit is reset to "0" when the system is reset as well as when the WDT counter overflows. It is reversed every
time data is written to the WDTCON register.
Two types of use are available: window function disabled mode and window function enabled mode.
・
Window function disabled mode
The WDT counter can always be cleared. The WDT interrupt is generated when the counter overflows for the first
time, and the WDT reset is generated when the counter overflows a second time.
・
Window function enabled mode
The periods during which WDT counter clear is enabled and disabled respectively can be set. The WDT reset is
generated when the counter overflows for the first time, and the WDT invalid clear reset is generated when the
counter is cleared in the period during which WDT counter clear is disabled.
Table 10-2 Watchdog Timer Operation Modes
Mode
Event in overflow
WDT invalid clear reset
First
Second
Window function disabled
mode
WDT interrupt
WDT reset
-
Window function enabled
mode
WDT reset
-
Generation enabled
The WDT counter overflow period (T
WOV
) and the WDT counter clear enabled period (T
WCL
) can be chosen through the
WDTMOD register.
The following items can be chosen with the code option. See Chapter 26 "Code Option" for details on how to set the
code option.
Ÿ
Enabling/disabling the WDT timer operation
Ÿ
Operation clock of the WDT counter (low-speed clock, WDTCLK)
Summary of Contents for ML62Q1000 Series
Page 17: ...Chapter 1 Overview...
Page 112: ...Chapter 2 CPU and Memory Space...
Page 154: ...Chapter 3 Reset Function...
Page 166: ...Chapter 4 Power Management...
Page 196: ...Chapter 5 Interrupts...
Page 248: ...Chapter 6 Clock generation Circuit...
Page 274: ...Chapter 7 Low Speed Time Base Counter...
Page 291: ...Chapter 8 16 Bit Timer...
Page 320: ...Chapter 9 Functional Timer FTM...
Page 382: ...Chapter 10 Watchdog Timer...
Page 402: ...Chapter 11 Serial Communication Unit...
Page 456: ...Chapter 12 I2 C Bus Unit...
Page 491: ...Chapter 13 I2 C Master...
Page 512: ...Chapter 14 DMA Controller...
Page 531: ...Chapter 15 Buzzer...
Page 550: ...Chapter 16 Simplified RTC...
Page 559: ...Chapter 17 GPIO...
Page 594: ...Chapter 18 External Interrupt Function...
Page 612: ...Chapter 19 CRC Generator...
Page 632: ...Chapter 20 Analog Comparator...
Page 644: ...Chapter 21 D A Converter...
Page 655: ...Chapter 22 Voltage Level Supervisor...
Page 676: ...Chapter 23 Successive Approximation Type A D Converter...
Page 709: ...Chapter 24 Regulator...
Page 714: ...Chapter 25 Flash Memory...
Page 743: ...Chapter 26 Code Option...
Page 750: ...Chapter 27 LCD Driver...
Page 788: ...Chapter 28 On Chip Debug Function...
Page 795: ...Chapter 29 Safety Function...
Page 813: ...Appendix A...
Page 881: ...Revision History...