100
CHAPTER 3 CLOCK GENERATOR AND CONTROLLER
Figure 3.11-2 Watchdog Timer Operating Timing
<Note>
•
The time interval between the first A5
H
and the next 5A
H
is not specified. Watchdog
resetting is postponed only if the time interval from one 5A
H
to the next 5A
H
is within the time
specified by the WT bits and one A5
H
is written between them.
•
If the first A5
H
is followed by something other than 5A
H
, the first A5
H
is ignored. Therefore,
A5
H
must be written again.
■
Timebase Timer
The timebase timer is used to supply clock pulses to the watchdog timer and is used also as the
oscillation stabilization wait timer. The operating clock
φ
is double the X0 when the GCR CHC is
1 or the cycle of the PLL oscillation frequency when the GCR CHC is 0.
The value of this timebase timer is set in the RFCR and used as the count clock for the count
value for DRAM refresh.
Figure 3.11-3 Timebase Timer Counter
Watchdog start
Watchdog clear
Watchdog resetting
Timebase timer overflow
Watchdog flip-flop
WTE write
1/2
1
1/2
2
1/2
3
1/2
18
1/2
19
1/2
20
1/2
21
Summary of Contents for MB91F109
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Page 3: ...FUJITSU LIMITED FR30 32 Bit Microcontroller MB91F109 Hardware Manual ...
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Page 10: ...vi ...
Page 24: ...xx ...
Page 96: ...72 CHAPTER 2 CPU ...
Page 224: ...200 CHAPTER 4 BUS INTERFACE ...
Page 234: ...210 CHAPTER 5 I O PORTS ...
Page 268: ...244 CHAPTER 9 U TIMER ...
Page 290: ...266 CHAPTER 10 UART ...
Page 314: ...290 CHAPTER 12 16 BIT RELOAD TIMER ...
Page 322: ...298 CHAPTER 13 BIT SEARCH MODULE ...
Page 392: ...368 CHAPTER 16 FLASH MEMORY ...
Page 432: ...408 APPENDIX E Instructions F Table E 2 Instruction Formats OP rel11 5 11 ...
Page 448: ...424 APPENDIX E Instructions ...
Page 449: ...425 INDEX INDEX The index follows on the next page This is listed in alphabetic order ...
Page 458: ...434 INDEX ...
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Page 461: ...FUJITSU SEMICONDUCTOR FR30 32 Bit Microcontroller MB91F109 Hardware Manual ...