The power-on reset voltage is confidential, and Cypress doesn’t guarantee the actual POR level. So please keep spec of Power up cycle.
Thank you for your support.
The following is described in the device data sheet.
"If during operation the power supply drops below the specifiedVDD minimum,
the system should issue a START condition prior to performing another operation."
It can be read when the reset condition occurs when the voltage falls below the minimum VDD voltage ( =4.5V ).
The voltage operation of FM24C16B-G is 4.5V to 5.5V.
Cypress cannot guarantee the device operation when the voltage is out of this range.
Voltage out of this range will make the device unstable and interrupt the operation.
So the system should issue a START condition prior to performing another operation.