An apparatus is provided for autonomous security and functional safety (FUSA) of clock and voltages. The apparatus may include: a multiplexer having a first input communicatively coupled to a pin to receive a first clock external to a die, and a second input coupled to an output of a divider; an oscillator to provide a second clock; and a counter coupled to an output of the multiplexer and the oscillator, wherein the counter is to operate with the second clock and is to determine a frequency of the first clock. The apparatus may further include a voltage monitor circuitry for monitoring voltage(s) for FUSA, a reference generator for FUSA, a duty cycle monitor for FUSA, a frequency degradation monitor for FUSA, and a phase error degradation monitor for FUSA.