CHAPTER 14 RESET FUNCTION
User’s Manual U16898EJ3V0UD
240
Figure 14-3. Timing of Reset by Overflow of Watchdog Timer
<1> With high-speed internal oscillation clock or external clock input
Hi-Z
Port pin
(except P130)
Port pin
(P130)
Note 2
Normal operation
in progress
CPU clock
Reset period
(oscillation stops)
Normal operation (reset processing, CPU clock)
Internal reset signal
High-speed internal oscillation clock or
external clock input
Operation stops because option
byte is referenced
Note 1
.
Watchdog overflow
Notes 1.
The operation stop time is 277
µ
s (MIN.), 544
µ
s (TYP.), and 1.075 ms (MAX.).
2.
Set high level output using software.
Caution The watchdog timer is also reset in the case of an internal reset of the watchdog timer.
Remark
When reset is effected, P130 outputs a low level. If P130 is set to output a high level before reset is
effected, the output signal of P130 can be dummy-output as the reset signal to the CPU.
<2> With crystal/ceramic oscillation clock
Hi-Z
Port pin
(P130)
Note 2
Port pin
(except P130)
Normal operation
in progress
Reset period
(oscillation stops)
Oscillation stabilization
time (2
10
/f
X
to 2
17
/f
X
)
Normal operation
(reset processing, CPU clock)
Internal reset signal
Crystal/ceramic
oscillation clock
Operation stops because option
byte is referenced
Note 1
.
CPU clock
Watchdog overflow
Notes 1.
The operation stop time is 276
µ
s (MIN.), 544
µ
s (TYP.), and 1.074 ms (MAX.).
2.
Set high level output using software.
Caution The watchdog timer is also reset in the case of an internal reset of the watchdog timer.
Remark 1.
f
X
: System clock oscillation frequency
2.
When reset is effected, P130 outputs a low level. If P130 is set to output a high level before reset is
effected, the output signal of P130 can be dummy-output as the reset signal to the CPU.