Voltage monitoring system and method for harvesting energy in a computational environment

A computing system for harvesting energy comprising:

• a hardware processor;
• an intermittent computation circuit communicatively connected to the hardware processor, the intermittent computation circuit is to monitor a buffer capacitor voltage for the intermittent computation circuit;
• a voltage monitoring system communicatively coupled to the intermittent computation circuit via the hardware processor, the voltage monitoring system comprises:
• a transistor-based voltage divider circuit to tune a ring oscillator circuit by operating the ring oscillator circuit in a preferred voltage region, the transistor-based voltage divider circuit being supplied with a supply voltage;
• the ring oscillator circuit to generate a voltage dependent ring oscillator frequency based on a tapped voltage of the transistor-based voltage divider circuit;
• a voltage-level shifter circuit to generate a level shifted output signal by shifting a voltage level of an intermediate output signal received from the ring oscillator circuit, the generated level-shifted output signal corresponds to a voltage level required by the intermittent computation circuit;
• and
• a counter circuit to generate a count value during a sampling period by incrementing an initial count value for each positive edge of the level-shifted output signal;
• and
• the intermittent computation circuit is to determine available energy level for computation by monitoring the buffer capacitor voltage for the intermittent computation circuit, the buffer capacitor voltage being monitored by mapping the count value to values of a pre-defined supply voltage.

A method for harvesting energy using a digital voltage monitoring system, the method comprising:

• measuring, by a hardware processor, a voltage dependent ring oscillator frequency at a ring oscillator circuit for a range of supply voltage levels;
• determining, by the hardware processor, a performance parameter for each of the measured voltage dependent ring oscillator frequency, the performance parameter comprising a resolution level and a sample rate;
• generating, by the hardware processor, a level shifted output signal by shifting voltage level of the ring oscillator circuit to a voltage level required by an intermittent computation circuit based on the determined performance parameter;
• generating, by the hardware processor, a count value during a sampling period by incrementing an initial count value for each positive edge of the generated level-shifted output signal;
• determining, by the hardware processor, an optimal supply voltage value for the intermittent computation circuit by mapping the count value to values of a pre-defined supply voltage;
• and
• identifying, by the hardware processor, an available energy level for computation based on the generated count values and the determined optimal supply voltage value, the available energy level corresponds to a n-bit value stored onto a destination register of the intermittent computation circuit.