HD6433935 Hitachi, HD6433935 Datasheet - Page 251

• Manufacturer Part Number: HD6433935
• Description: 8-Bit MICROCONTROLLER
• Manufacturer: Hitachi

Figure 9-18 shows an example of watchdog timer operations.
9.6.4
Table 9-18 summarizes the watchdog timer operation states.
Table 9-18 Watchdog Timer Operation States
Operation
Mode
TCW
TCSRW
Note:
Internal reset
signal
TCW count
value
*
H'FF
H'00
Watchdog Timer Operation States
Functions when øw/32 is selected as the input clock.
Reset
Reset
Reset
Example: ø = 2 MHz and the desired overflow period is 30 ms.
The value set in TCW should therefore be 256 – 8 = 248 (H'F8).
Figure 9-18 Typical Watchdog Timer Operations (Example)
H'F8
H'F8 written
in TCW
Active
Functions Functions Halted
Functions Functions Retained
2
8192
10
Start
6
Sleep
30
H'F8 written in TCW
10
Watch
–3
= 7.3
Subactive Subsleep Standby
Functions/
Halted*
Functions/
Halted*
512 ø
Halted
Retained
Reset
OSC
TCW overflow
clock cycles
Halted
Retained
Module
Standby
Halted
Retained
239