276
CHAPTER 15 WATCH TIMER
15.5
Explanation of Operation of Watch Timer
The watch timer operates as an interval timer or an oscillation stabilization wait time
timer of subclock. It also supplies an operation clock to the watchdog timer.
■
Watch Timer Counter
The watch timer counter continues incrementing in synchronization with the subclock (SCLK) while the
subclock (SCLK) is operating.
●
Clearing watch timer counter
The watch timer counter is cleared to "0000
H
" when:
•
A power-on reset occurs.
•
The mode transits to the stop mode.
•
The watch timer clear bit (WTR) in the watch timer control register (WTC) is set to "0".
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.
To clear the watch timer by writing zero to 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 "0" and set the watch
timer to interrupt inhibited state. Before permitting an interrupt, clear the interrupt request issued by
writing zero to the overflow flag bit (WTOF) in the WTC register.
■
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 15.5-1 .
Figure 15.5-1 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.
•
The overflow flag bit (WTC:WTOF) is set when the interval time is reached at the starting point of the
timing at which the watch timer is finally cleared.
WTC
6
5
4
3
2
1
WTOF WTR
WTC1
WTC2
SCE WTIE
WTC0
WDCS
bit7
bit0
: Used bit
: Unused bit
Summary of Contents for F2MCTM-16LX
Page 2: ......
Page 3: ...FUJITSU LIMITED F2MCTM 16LX 16 BIT MICROCONTROLLER MB90360 Series HARDWARE MANUAL ...
Page 4: ......
Page 42: ...26 CHAPTER 1 OVERVIEW ...
Page 70: ...54 CHAPTER 2 CPU ...
Page 134: ...118 CHAPTER 6 CLOCK SUPERVISOR ...
Page 176: ...160 CHAPTER 8 LOW POWER CONSUMPTION MODE ...
Page 194: ...178 CHAPTER 10 I O PORTS ...
Page 252: ...236 CHAPTER 13 16 Bit I O TIMER ...
Page 282: ...266 CHAPTER 14 16 BIT RELOAD TIMER ...
Page 296: ...280 CHAPTER 15 WATCH TIMER ...
Page 386: ...370 CHAPTER 18 8 10 BIT A D CONVERTER ...
Page 426: ...410 CHAPTER 20 LIN UART Figure 20 5 2 ORE Flag Set Timing RDRF ORE Reception data ...
Page 540: ...524 CHAPTER 22 ADDRESS MATCH DETECTION FUNCTION ...
Page 568: ...552 CHAPTER 24 512K BIT FLASH MEMORY ...
Page 633: ...617 APPENDIX B Instructions Table B 9 3 Bit Operation Instruction Map first byte 6CH ...
Page 634: ...618 APPENDIX Table B 9 4 Character String Operation Instruction Map first byte 6EH ...
Page 637: ...621 APPENDIX B Instructions Table B 9 7 ea Instruction 2 first byte 71H ...
Page 638: ...622 APPENDIX Table B 9 8 ea Instruction 3 first byte 72H ...
Page 639: ...623 APPENDIX B Instructions Table B 9 9 ea Instruction 4 first byte 73H ...
Page 640: ...624 APPENDIX Table B 9 10 ea Instruction 5 first byte 74H ...
Page 641: ...625 APPENDIX B Instructions Table B 9 11 ea Instruction 6 first byte 75H ...
Page 642: ...626 APPENDIX Table B 9 12 ea Instruction 7 first byte 76H ...
Page 643: ...627 APPENDIX B Instructions Table B 9 13 ea Instruction 8 first byte 77H ...
Page 644: ...628 APPENDIX Table B 9 14 ea Instruction 9 first byte 78H ...
Page 645: ...629 APPENDIX B Instructions Table B 9 15 MOVEA RWi ea Instruction first byte 79H ...
Page 646: ...630 APPENDIX Table B 9 16 MOV Ri ea Instruction first byte 7AH ...
Page 647: ...631 APPENDIX B Instructions Table B 9 17 MOVW RWi ea Instruction first byte 7BH ...
Page 648: ...632 APPENDIX Table B 9 18 MOV Ri ea Instruction first byte 7CH ...
Page 649: ...633 APPENDIX B Instructions Table B 9 19 MOVW ea Rwi Instruction first byte 7DH ...
Page 650: ...634 APPENDIX Table B 9 20 XCH Ri ea Instruction first byte 7EH ...
Page 651: ...635 APPENDIX B Instructions Table B 9 21 XCHW RWi ea Instruction first byte 7FH ...
Page 664: ...648 APPENDIX ...
Page 665: ...649 INDEX INDEX The index follows on the next page This is listed in alphabetic order ...
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