upd70f3402 Renesas Electronics Corporation., upd70f3402 Datasheet - Page 359

• Manufacturer Part Number: upd70f3402
• Description: 32-/16-bit Single-chip Microcontroller With Can Interface
• Manufacturer: Renesas Electronics Corporation.

10.1 Functions
Watchdog Timer 2 has the following functions.
Notes: 1. Watchdog timer 2 automatically starts in the reset mode following reset release.
Remark:
f
• Default start Watchdog timer
• Input selectable from main oscillator and ring oscillator as the source clock.
XX
f
R
Reset mode: Reset operation upon overflow of Watchdog timer 2 (generation of WDT2RES
signal)
Non-maskable interrupt request mode: NMI operation upon overflow of Watchdog timer 2
(generation of INTWDT2 signal)
2. Restoring using the RETI instruction following non-maskable interrupt servicing due to a
/2
/2
9
3
Watchdog Timer Enable
When Watchdog timer 2 is not used, either stop its operation before reset is executed
through this function, or clear Watchdog timer 2 once and stop it within the next interval
time.
Also, perform write for verification purposes only once, even if the default settings (reset
mode, interval time: f
non-maskable interrupt request (INTWDT2) is not possible. Therefore, following completion
of interrupt servicing, perform a system reset.
f
f
INTWDT2: Non-maskable interrupt request signal from Watchdog Timer 2
WDT2RES: Watchdog Timer 2 reset signal
XX
R
Register (WDTE)
:
:
Controller
Clock
Input
2
Chapter 10 Functions of Watchdog Timer 2
PLL output oscillation frequency
Ring-OSC clock frequency
Figure 10-1: Block Diagram of Watchdog Timer 2
User’s Manual U16702EE3V2UD00
Counter
R
16-bit
/2
19
Note 1
0
) need not be changed.
Note 2
WDM21
Watchdog Timer Mode
Register 2 (WDTM2)
WDM20
Selector
3
WDCS24
Internal Bus
Controller
WDCS23
Output
3
WDCS22
INTWDT2
WDT2RES
(internal reset signal)
WDCS21
WDCS20
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