Cypress FM4 Series - Explanation of Operations

CHAPTER 5: Low-voltage Detection
178 FM4 Peripheral Manual, Doc. No. 002-04856 Rev. *E
3. Explanation of Operations
This section explains the operations of the Low-Voltage Detection Reset Circuit and the Low-voltage
Detection Interrupt Circuit.
Operations of Low-Voltage Detection Reset Circuit
 Operations
The Low-Voltage Detection Reset Circuit always enters a monitoring state after power-on. This circuit
generates a reset signal when the power supply voltage (VCC) falls below the detection voltage. A reset
is released when the power supply voltage exceeds the release voltage.
This circuit is available in standby modes (SLEEP mode, TIMER mode, RTC mode, STOP mode) and
deep standby modes (Deep standby RTC mode, Deep standby STOP mode).
Note:
− For the hysteresis of detection / release voltage of the Low-voltage Detection Circuit, see Data
Sheet of the product used.
Detection or release voltage
Power supply voltage
(VCC)
Lower limit voltage
A
:
Low-voltage detection reset detection delay time
reset enable signal
(LVDRE)
Operation state of
the Low-voltage
Detection Circuit
Power-on
Monitoring
Reset
Reset
Monitoring
A
A
A
Low-voltage detection
Low-voltage
Detection Circuit
reset signal
(L active)