4554 Datasheet, PDF (51/138 Pages) Renesas Technology Corp – SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER

4554 Group
RESET FUNCTION
System reset is performed by applying “L” level to RESET pin for
1 machine cycle or more when the following condition is satisfied;
the value of supply voltage is the minimum value or more of the
recommended operating conditions.
Then when “H” level is applied to RESET pin, software starts from
address 0 in page 0.
f(XIN)
RESET
On-chip oscillator (internal oscillator)
is counted 5400 to 5424 times.
Program starts
(address 0 in page 0)
Note: The number of clock cycles depends on the internal state of
the microcomputer when reset is performed.
Fig. 37 Reset release timing
Reset input
1 machine cycle or more
On-chip oscillator (internal oscillator) is
counted 5400 to 5424 times.
0.85VDD
RESET
0.3VDD
Program starts
(address 0 in page 0)
(Note)
Note: Keep the value of supply voltage to the minimum value
or more of the recommended operating conditions.
Fig. 38 RESET pin input waveform and reset operation
Rev.3.00 Aug 06, 2004 page 51 of 136
REJ03B0043-0300Z