
ML62Q1000 Series User's Manual
Chapter 10 Watchdog Timer
FEUL62Q1000
10-19
The following figure shows details of operation timing in the window function enabled mode.
Figure 10-12
Details of Operation Timing in Window Function Enabled Mode
(1)
After the system reset is released, the WDT counter starts counting up.
(2)
The WDTMOD register is set with the WDT counter overflow period (TWOV) and WDT clear enabled period.
(3)
"0x5A" is written to WDTCON during the WDT clear enabled period. (Internal pointer WDP: 0
à
1)
(4)
"0xA5" is written to the WDTCON register to clear the WDT counter. (Internal pointer WDP: 1
à
0)
(5)
"0x5AH" is written to WDTCON during the WDT clear enabled period. (Internal pointer WDP: 0
à
1)
(6)
Occurrence of abnormality
(7)
The WDT counter overflows and a WDT reset occurs. (Internal pointer WDP: 1
à
0)
[Note]
Ÿ
In the watchdog timer (WDT) interrupt function, as the interrupt level (ELEVEL) of the CPU program
status word (PSW) becomes "2", the WDT counter is uncleared. Clear the WDT when the ELEVEL is "0"
or "1". It is recommended that the WDT counter is cleared at one place in the main loop of the program
as a fail-safe.
(3)
5A
(4)
A5
(5)
5A
(6) Error occurs
Overflow
WDT clock
oscillation starts
(1)
Program start
5A A5
Data:
RESET_N
System reset
WDTCON register
write
WDT counter
WDT reset
T
WOV
Overflow period
(2) WDTMOD
setting
WDTMOD
setting
(7) WDT reset generated
Internal pointer
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...