286
CHAPTER 9 Watch timer
9.5
Explanation of Operation of Watch Timer
The watch timer operates as an interval timer or an oscillation stabilization wait time
timer of the sub clock.It also supplies an operation clock to the watchdog timer.
■
Watch timer counter
The watch timer counter continues incrementing in synchronization with the sub clock (SCLK) while the
sub clock (SCLK) is operating.
●
Clearing watch timer counter
The watch timer counter is cleared to "0000
H
" when:
•
Power on reset
•
The mode transits to the stop mode.
•
The watch timer clear bit (WTR) in the watch timer control register (WTC) is set to 0.
■
Interval Timer Function
The watch timer can be used as an interval timer by generating an interrupt at each interval time.
●
Settings when using watch timer as interval timer
Operating the watch timer as an interval timer requires the settings shown in Figure 9.5-1.
Figure 9.5-1 Setting of Watch Timer
•
When the value set by the interval time select bits (WTC1, WTC0) in the watch timer control register
(WTC) is reached, the overflow flag bit in the WTC register is set to 1 (WTC: WTOF = 1).
•
When the overflow flag bit is set (WTC: WTOF = 1) with the overflow interrupt of the watch timer
counter enabled (WTC: WTIE = 1), an interrupt request is generated.
Note:
When the watch timer counter is cleared, the interrupts of the watchdog timer and interval
timer that use the output of the watch timer counter are affected.
Before clearing the watch timer by setting the watch timer clear bit (WTR) in the watch timer
control register (WTC), set the overflow interrupt enable bit (WTIE) in the WTC register to
disable the watch timer for interrupts.Before enabling interrupts, set the WTC overflow flag
bit (WTOF) to clear the interrupt request.
WTC
6
5
4
3
2
1
: Unused bit
: Used bit
WTOF WTR
WTC1
WTC2
SCE WTIE
WTC0
WDCS
bit7
bit0
Summary of Contents for F2MC-16LX Series
Page 2: ......
Page 3: ...FUJITSU LIMITED F2MC 16LX 16 bit Microcontroller MB90895 series Hardware Manual ...
Page 4: ......
Page 8: ...iv ...
Page 10: ...vi ...
Page 36: ...18 CHAPTER 2 HANDLING DEVICES ...
Page 176: ...158 CHAPTER 3 CPU ...
Page 224: ...206 CHAPTER 5 Timebase timer ...
Page 294: ...276 CHAPTER 8 16 bit reload timer ...
Page 366: ...348 CHAPTER 12 DTP external interrupt ...
Page 398: ...380 CHAPTER 13 8 10 bit A D converter ...
Page 446: ...428 CHAPTER 14 UART0 ...
Page 588: ...570 CHAPTER 17 Address Match Detecting Function ...
Page 626: ...608 CHAPTER 19 512 KBIT FLASH MEMORY ...
Page 676: ...658 APPENDIX Table A 9 3 Bit Operation Instruction Map first byte 6CH ...
Page 678: ...660 APPENDIX Table A 9 5 2 byte Instruction Map first byte 6FH MUL MULW DIVU A A A ...
Page 680: ...662 APPENDIX Table A 9 7 ea Instruction 2 first byte 71H ...
Page 681: ...663 APPENDIX A Instructions Table A 9 8 ea Instruction 3 first byte 72H ...
Page 682: ...664 APPENDIX Table A 9 9 ea Instruction 4 first byte 73H ...
Page 683: ...665 APPENDIX A Instructions Table A 9 10 ea Instruction 5 first byte 74H ...
Page 684: ...666 APPENDIX Table A 9 11 ea Instruction 6 first byte 75H ...
Page 685: ...667 APPENDIX A Instructions Table A 9 12 ea Instruction 7 first byte 76H ...
Page 686: ...668 APPENDIX Table A 9 13 ea Instruction 8 first byte 77H ...
Page 687: ...669 APPENDIX A Instructions Table A 9 14 ea Instruction 9 first byte 78H ...
Page 688: ...670 APPENDIX Table A 9 15 MOVEA RWi ea Instruction first byte 79H ...
Page 689: ...671 APPENDIX A Instructions Table A 9 16 MOV Ri ea Instruction first byte 7AH ...
Page 690: ...672 APPENDIX Table A 9 17 MOVW RWi ea Instruction first byte 7BH ...
Page 691: ...673 APPENDIX A Instructions Table A 9 18 MOV ea Ri Instruction first byte 7CH ...
Page 692: ...674 APPENDIX Table A 9 19 MOVW ea Rwi Instruction first byte 7DH ...
Page 693: ...675 APPENDIX A Instructions Table A 9 20 XCH Ri ea Instruction first byte 7EH ...
Page 694: ...676 APPENDIX Table A 9 21 XCHW RWi ea Instruction first byte 7FH ...
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