Toshiba H1 Series Data Book page 618

3.24 Watchdog Timer (Runaway detection timer)
The TMP92CZ26A contains a watchdog timer of runaway detecting.
The watchdog timer (WDT) is used to return the CPU to the normal state when it detects that
the CPU has started to malfunction (runaway) due to causes such as noise. When the watchdog
timer detects a malfunction, it generates a non-maskable interrupt INTWD to notify the CPU of
the malfunction.
Connecting the watchdog timer output to the reset pin internally forces a reset.
(The level of external
3.24.1 Configuration
Figure 3.24.1 is a block diagram of the watchdog timer (WDT).
f
IO
Internal reset
Note: It needs to care designing the total machine set, because Watchdog timer can't operate completely by
external noise.
pin is not changed.)
RESET
WDMOD
Selector
<WDTP1:0>
15 17
2 2 2
Binary counter
(22 stages)
Reset
Write
4EH
WDT control register WDCR
Internal data bus
Figure 3.24.1 Block Diagram of Watchdog Timer
92CZ26A-615
WDMOD<RESCR>
Reset control
19 21
2
Q
R S
Write
B1H
WDMOD
<WDTE>
TMP92CZ26A
pin
RESET
Internal reset
INTWD interrupt