4570 Datasheet, PDF (31/69 Pages) Renesas Technology Corp – SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER

MITSUBISHI MICROCOMPUTERS
4570 Group
SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER
VOLTAGE DROP DETECTION CIRCUIT
The built-in voltage drop detection circuit is designed to detect a
drop in voltage and to reset the microcomputer if the supply
voltage drops below a set value.
The voltage drop detection circuit is not operated at the RAM
back-up mode.
Pull-up transistor
RESET pin
Power-on
reset circuit
Internal reset signal
Voltage drop detection circuit
Watchdog timer output
WEF
Fig. 27 Voltage drop detection reset circuit
VDD
Reset voltage
Internal reset
signal
The microcomputer starts operation
after the f(XIN) is counted 10757 to
10786 times.
Note: Set the VDCE pin to “H” level to operate the
voltage drop detection circuit.
Fig. 28 Voltage drop detection circuit operation waveform
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