Datasheet

Section 26 Electrical Characteristics
Rev. 2.00 Jul. 04, 2007 Page 597 of 692
REJ09B0309-0200
26.4.6 Power-On Reset Circuit Characteristics
Table 26.18 Power-On Reset Circuit Characteristics
V
CC
= 1.8 V to 3.6 V, AV
CC
= 1.8 V to 3.6 V, V
SS
= AV
SS
= 0.0 V,
Ta = −20 to +75°C (general specifications), Ta = −40 to +85°C (wide temperature range
specifications), unless otherwise specified.
Values
Item Symbol
Test
Condition Min. Typ. Max. Unit
Reference
Figure
Reset voltage V_rst 0.7V
CC
0.8V
CC
0.9V
CC
V
Power supply rise time t_vtr The Vcc rise time should be shorter than
half the RES rise time.
Figure 23.2
0.8 — 4.0 µs Reset count time t_out
0.8 — 16.0 µs On-chip oscillator
for system clock
selected
(Reference
value)
Count start time t_cr Adjustable by the value of the external
capacitor of the RES pin.
On-chip pull-up resistance R
P
Vcc = 3.0 V 60 100 — kΩ Figure 23.1
26.4.7 Watchdog Timer Characteristics
Table 26.19 Watchdog Timer Characteristics
V
CC
= 1.8 V to 3.6 V, AV
CC
= 1.8 V to 3.6 V, V
SS
= AV
SS
= 0.0 V,
Ta = −20 to +75°C (regular specifications), Ta = −40 to +85°C (wide-range specifications),
unless otherwise specified.
Values
Item Symbol
Applicable
Pins
Test
Condition Min. Typ. Max. Unit Note
On-chip watchdog
timer oscillator
overflow time
t
ovf
0.2 0.4 — s *
Note: * Indicates the period from the start of counting at 0 to the generation of an internal reset
when the counter reaches 255 in the case where the on-chip watchdog timer oscillator
is selected.