upd78f0124hgba1-8et-a Renesas Electronics Corporation., upd78f0124hgba1-8et-a Datasheet - Page 211

• Manufacturer Part Number: upd78f0124hgba1-8et-a
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

<R>
10.1 Functions of Watchdog Timer
signal is generated.
For details of RESF, refer to CHAPTER 19 RESET FUNCTION.
internal oscillator as shown in Table 10-2.
The watchdog timer is used to detect an inadvertent program loop. If a program loop is detected, an internal reset
When a reset occurs due to the watchdog timer, bit 4 (WDTRF) of the reset control flag register (RESF) is set to 1.
The operation mode of the watchdog timer (WDT) is switched according to the option byte setting of the on-chip
Remarks 1. f
2
2
2
2
2
2
2
2
11
12
13
14
15
16
17
18
During Internal Oscillation Clock Operation
/f
/f
/f
/f
/f
/f
/f
/f
R
R
R
R
R
R
R
R
(4.27 ms)
(8.53 ms)
(17.07 ms)
(34.13 ms)
(68.27 ms)
(136.53 ms)
(273.07 ms)
(546.13 ms)
2. f
3. Figures in parentheses apply to operation at f
Table 10-1. Loop Detection Time of Watchdog Timer
R
XP
: Internal oscillation clock oscillation frequency
: High-speed system clock oscillation frequency
CHAPTER 10 WATCHDOG TIMER
User’s Manual U16962EJ3V0UD
Loop Detection Time
2
2
2
2
2
2
2
2
During High-Speed System Clock Operation
13
14
15
16
17
18
19
20
/f
/f
/f
/f
/f
/f
/f
/f
XP
XP
XP
XP
XP
XP
XP
XP
(819.2
(1.64 ms)
(3.28 ms)
(6.55 ms)
(13.11 ms)
(26.21 ms)
(52.43 ms)
(104.86 ms)
µ
s)
R
= 480 kHz (MAX.), f
XP
= 10 MHz
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