FUJITSU F2MCTM-16LX - Manual (Page 388)

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CHAPTER 19 LOW VOLTAGE DETECTION/CPU OPERATING DETECTION RESET
19.1 Overview of Low Voltage/CPU Operating Detection Reset
Circuit
The low voltage detection reset circuit watches the power-supply voltage and has the
function to detect the power-supply voltages falling lower than the detection voltage
values. When the low voltage is detected, internal reset is generated.
When the counter is not cleared within the fixed time after 20-bit counter start that
makes the oscillation clock a count clock, CPU operating detection reset circuit
generates internal reset.
■ Low Voltage Detection Reset Circuit
Figure 19.1-1 Detection Voltage of Low Voltage/CPU operating Detection Reset Circuit
After detecting the low voltage, low voltage detection flag (LVRC:LVRF) is set to "1", and internal reset is
outputted.
After the low voltage is detected, internal reset is generated and the STOP mode is canceled, because of
that keep operating at the STOP mode.
After writing ends, low voltage reset is generated for internal RAM writing period.
4.0V
±
0.3V
Detection voltage