Watchdog Timer Operation States - Hitachi HD6473867 Hardware Manual

H'FF
H'F8
TCW count
value
H'00
Internal reset
signal
Figure 9-17 Typical Watchdog Timer Operations (Example)

9.6.4 Watchdog Timer Operation States

Table 9-18 summarizes the watchdog timer operation states.
Table 9-18 Watchdog Timer Operation States
Operation Mode
TCW
TCSRW
Note: * Functions when øw/32 is selected as the input clock.
Start
H'F8 written
in TCW
Reset Active Sleep
Reset Functions Functions
Reset Functions Functions
H'F8 written in TCW
Sub-
Watch active
Halted Functions/ Halted
Halted*
Retained Functions/ Retained
Halted*
238
TCW overflow
Reset
512 ø clock cycles
OSC
Sub-
sleep Standby Standby
Halted
Retained Retained
Module
Halted