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CHAPTER 3 MEMORY SPACE, CPU AND CONTROL UNIT
3.11.8 Watchdog Function
The watchdog function can detect a "program crashed" status. Assume that A5
H
and
5A
H
could not be written to the watchdog reset delay register within the given time due
to a program crash. In this case, the watchdog timer generates a watchdog reset
request.
■
Diagram of the watchdog function
Figure 3.11-3 "Block diagram of the watchdog control block" shows a diagram of the watchdog
function.
Figure 3.11-3 Block diagram of the watchdog control block
■
Activating the watchdog timer
The watchdog timer starts its operation when a value is written to the watchdog control register
(WTCR). The interval time of the watchdog timer is set with bits WT1 and WT0. Only the time
set in the first writing operation becomes valid as the interval time. Subsequent settings are
ignored.
[Example]
A5&5A
WDOG
WTx
CTBR
WPR
RSRR
Edge
Detect
clr
Time-base
timer
Watchdog
F/F
Latch
Reset
generation F/F
Internal reset
Status decoder
Reset status transition
request signal
Status transition
control circuit
Internal bus
LDI:8 #10000000b,R1 ; WT1,0=10
LDI:32 #WTCR,R2
STB R1,@R2 ; Watchdog activation
Summary of Contents for MB91150 Series
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Page 3: ...FUJITSU LIMITED FR30 32 BIT MICROCONTROLLER MB91150 Series HARDWARE MANUAL ...
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Page 10: ...vi ...
Page 112: ...96 CHAPTER 3 MEMORY SPACE CPU AND CONTROL UNIT ...
Page 178: ...162 CHAPTER 5 I O PORTS ...
Page 214: ...198 CHAPTER 7 16 BIT RELOAD TIMER ...
Page 240: ...224 CHAPTER 8 PPG TIMER ...
Page 310: ...294 CHAPTER 13 8 10 BIT A D CONVERTER ...
Page 318: ...302 CHAPTER 14 8 BIT D A CONVERTER ...
Page 362: ...346 CHAPTER 15 UART ...
Page 420: ...404 CHAPTER 19 PERIPHERAL STOP CONTROL ...
Page 428: ...412 CHAPTER 20 CALENDAR MACROS ...
Page 503: ...487 INDEX INDEX The index follows on the next page This is listed in alphabetic order ...
Page 510: ...494 INDEX ...
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