If the VCC voltage drops, the voltage on the PLC line will also drop along with VCC. If PLC voltage goes below 2.45V for more than 2.5ms, the master detects this a “PLC Short Circuit” and enters SAFE state. Even when the VCC and PLC voltages recover to values above 2.45V, the master will not automatically exit the SAFE state. It will remain in the SAFE state until the bit DET_RST ( Reg_0x01[1] = CONTROL1[1] ) is forced HIGH to restart slave detection.