tmp86c809ng TOSHIBA Semiconductor CORPORATION, tmp86c809ng Datasheet - Page 70

• Manufacturer Part Number: tmp86c809ng
• Description: 8 Bit Microcontroller Tlcs-870/c Series
• Manufacturer: TOSHIBA Semiconductor CORPORATION

7.2 Watchdog Timer Control
7.2.3 Watchdog Timer Disable
7.2.4 Watchdog Timer Interrupt (INTWDT)
Example :Disabling the watchdog timer
Example :Setting watchdog timer interrupt
ister in other procedures causes a malfunction of the microcontroller.
by the binary-counter overflow.
master flag (IMF).
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 disable the watchdog timer, set the register in accordance with the following procedures. Setting the reg-
Note:While the watchdog timer is disabled, the binary counters of the watchdog timer are cleared.
When WDTCR1<WDTOUT> is cleared to “0”, a watchdog timer interrupt request (INTWDT) is generated
A watchdog timer interrupt is the non-maskable interrupt which can be accepted regardless of the interrupt
When a watchdog timer interrupt is generated while the other interrupt including a watchdog timer interrupt
To generate a watchdog timer interrupt, set the stack pointer before setting WDTCR1<WDTOUT>.
Table 7-1 Watchdog Timer Detection Time (Example: fc = 16.0 MHz, fs = 32.768 kHz)
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).
WDTT
00
01
10
11
DI
LD
LDW
LD
LD
(WDTCR2), 04EH
(WDTCR1), 0B101H
SP, 023FH
(WDTCR1), 00001000B
DV7CK = 0
524.288 m
131.072 m
32.768 m
2.097
Watchdog Timer Detection Time[s]
NORMAL1/2 mode
Page 60
: IMF
: WDTEN
: WDTOUT
: Clears the binary coutner
: Sets the stack pointer
←
0
←
←
DV7CK = 1
0, WDTCR2
62.5 m
250 m
0
4
1
←
Disable code
62.5 m
SLOW
250 m
mode
4
1
TMP86C809NG