upd78f0148m1gka1-9eu Renesas Electronics Corporation., upd78f0148m1gka1-9eu Datasheet - Page 252

• Manufacturer Part Number: upd78f0148m1gka1-9eu
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

11.1 Functions of Watchdog Timer
signal is generated.
For details of RESF, see CHAPTER 22 RESET FUNCTION.
oscillator as shown in Table 11-2.
252
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 mask option setting of the internal
Remarks 1. f
2
2
2
2
2
2
2
2
During Internal Oscillation Clock Operation
11
12
13
14
15
16
17
18
/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 11-1. Loop Detection Time of Watchdog Timer
(A) grade products), f
R
XP
: Internal oscillation clock frequency
: X1 input clock oscillation frequency
CHAPTER 11 WATCHDOG TIMER
User’s Manual U15947EJ3V1UD
Loop Detection Time
XP
= 10 MHz.
2
2
2
2
2
2
2
2
13
14
15
16
17
18
19
20
/f
/f
/f
/f
/f
/f
/f
/f
XP
XP
XP
XP
XP
XP
XP
XP
During X1 Input Clock Operation
(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.) (standard products,