m37905 Renesas Electronics Corporation., m37905 Datasheet - Page 362

• Manufacturer Part Number: m37905
• Description: Mitsubishi 16-bit Single-chip Microcomputer 7700 Family / 7900 Series
• Manufacturer: Renesas Electronics Corporation.

Note: This applies when the peripheral device’s clock
14.2 Operation description
The operations of the watchdog timer are described below.
Table 14.2.1 Occurrence interval of watchdog timer
frequency select bit
14.2.1 Basic operation
A watchdog timer interrupt is a non-maskable interrupt. When a watchdog timer interrupt request is accepted,
the processor interrupt priority level (IPL) is set to “111
Watchdog timer
interrupt request occurs. (See Table 14.2.1.)
Watchdog timer starts counting down from “FFF
When the watchdog timer’s most significant bit becomes “0” (counted 2048 times), a watchdog timer
When the interrupt request occurs in above
select bits 1, 0 (bits 7, 6 at address BC
0
1
interrupt request
Count source
Wf
Wf
512
32
f(f
sys
) = 20 MHz
Occurrence interval (Note)
52.43 ms
3.28 ms
7905 Group User’s Manual Rev.1.0
16
) = “00
2
.”
, a value of “FFF
16
.”
2
.”
16
” is set to the watchdog timer.
WATCHDOG TIMER
14.2 Operation description
14-5