TMP91C824
91C824-193
2008-02-20
The watchdog timer consists of a 22-stage binary counter which uses the system clock
(f
SYS
) as the input clock. The binary counter can output f
SYS
/2
15
, f
SYS
/2
17
, f
SYS
/2
19
and
f
SYS
/2
21
.
Figure 3.12.2 NORMAL Mode
The runaway is detected when an overflow occurs, and the watchdog timer can reset
device. In this case, the reset time will be between 22 and 29 states (21.3~28.1
µ
s at f
OSCH
=
33MHz, f
FPH
=
2.2 MHz) is f
FPH
/2, where f
FPH
is generated by diving the high-speed
oscillator clock (f
OSCH
) by sixteen through the clock gear function.
Figure 3.12.3 Reset Mode
0
WDT interrupt
WDT clear
(Software)
Write clear code
WDT counter
n
Overflow
Overflow
WDT counter
n
WDT interrupt
22 to 29 states
(21.3 to 28.1
µ
s at f
OSCH
=
33 MHz, f
FPH
=
2.2 MHz)
Internal reset