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6. Watchdog Timer (WDT)
6.2 Watchdog Timer Control
TMP86PM29BUG
6.2.3
Watchdog Timer Disable
To disable the watchdog timer, set the register in accordance with the following procedures. Setting the reg-
ister in other procedures causes a malfunction of the microcontroller.
1. Set the interrupt master flag (IMF) to “0”.
2. Set WDTCR2 to the clear code (4EH).
3. Set WDTCR1<WDTEN> to “0”.
4. Set WDTCR2 to the disable code (B1H).
Note:While the watchdog timer is disabled, the binary counters of the watchdog timer are cleared.
6.2.4
Watchdog Timer Interrupt (INTWDT)
When WDTCR1<WDTOUT> is cleared to “0”, a watchdog timer interrupt request (INTWDT) is generated
by the binary-counter overflow.
A watchdog timer interrupt is the non-maskable interrupt which can be accepted regardless of the interrupt
master flag (IMF).
When a watchdog timer interrupt is generated while the other interrupt including a watchdog timer interrupt
is already accepted, the new watchdog timer interrupt is processed immediately and the previous interrupt is
held pending. Therefore, if watchdog timer interrupts are generated continuously without execution of the
RETN instruction, too many levels of nesting may cause a malfunction of the microcontroller.
To generate a watchdog timer interrupt, set the stack pointer before setting WDTCR1<WDTOUT>.
Example :Disabling the watchdog timer
DI
: IMF
←
0
LD
(WDTCR2), 04EH
: Clears the binary counter
LDW
(WDTCR1), 0B101H
: WDTEN
←
0, WDTCR2
←
Disable code
Table 6-1 Watchdog Timer Detection Time (Example: fc = 16.0 MHz, fs = 32.768 kHz)
WDTT
Watchdog Timer Detection Time[s]
NORMAL1/2 mode
SLOW
mode
DV7CK = 0
DV7CK = 1
00
2.097
4
4
01
524.288 m
1
1
10
131.072 m
250 m
250 m
11
32.768 m
62.5 m
62.5 m
Example :Setting watchdog timer interrupt
LD
SP, 063FH
: Sets the stack pointer
LD
(WDTCR1), 00001000B
: WDTOUT
←
0
Содержание TLCS-870/C Series
Страница 1: ...8 Bit Microcontroller TLCS 870 C Series TMP86PM29BUG ...
Страница 6: ...TMP86PM29BUG ...
Страница 7: ...Revision History Date Revision 2007 10 11 1 First Release 2008 8 29 2 Contents Revised ...
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Страница 19: ...Page 4 1 3 Block Diagram TMP86PM29BUG 1 3 Block Diagram Figure 1 2 Block Diagram ...
Страница 23: ...Page 8 1 4 Pin Names and Functions TMP86PM29BUG ...
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Страница 49: ...Page 34 2 Operational Description 2 3 Reset Circuit TMP86PM29BUG ...
Страница 61: ...Page 46 3 Interrupt Control Circuit 3 8 External Interrupts TMP86PM29BUG ...
Страница 81: ...Page 66 6 Watchdog Timer WDT 6 3 Address Trap TMP86PM29BUG ...
Страница 135: ...Page 120 10 8 Bit TimerCounter TC5 TC6 10 1 Configuration TMP86PM29BUG ...
Страница 145: ...Page 130 11 Asynchronous Serial interface UART 11 9 Status Flag TMP86PM29BUG ...
Страница 165: ...Page 150 13 10 bit AD Converter ADC 13 6 Precautions about AD Converter TMP86PM29BUG ...
Страница 183: ...Page 168 15 LCD Driver 15 4 Control Method of LCD Driver TMP86PM29BUG ...
Страница 201: ...Page 186 18 Electrical Characteristics 18 9 Handling Precaution TMP86PM29BUG ...
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