Apparatus and method for implementing a scalable digital infrastructure for measuring ring oscillators

An apparatus, comprising:

• a collection of ring oscillators;
• an instruction register block configured to sequentially address and activate each ring oscillator in the collection of ring oscillators;
• a multiplexer with input lines connected to each ring oscillator in the collection of ring oscillators and an output line;
• a pulse counter connected to the output line of the multiplexer to count the number of oscillations of a selected ring oscillator within a selected time period to form a multiple bit frequency count output signal;
• and
• a data shift register to receive the multiple bit frequency count output signal and produce a serial frequency count output signal, wherein the pulse counter comprises serially connected clocked divide-by-2 cells with a sticky-bit cell to identify an overflow condition.

An apparatus, comprising:

• a collection of ring oscillators;
• an instruction register block configured to sequentially address and activate each ring oscillator in the collection of ring oscillators;
• a multiplexer with input lines connected to each ring oscillator in the collection of ring oscillators and an output line;
• a pulse counter connected to the output line of the multiplexer to count the number of oscillations of a selected ring oscillator within a selected time period to form a multiple bit frequency count output signal;
• and
• a data shift register to receive the multiple bit frequency count output signal and produce a serial frequency count output signal, wherein the pulse counter comprises serially connected self-clocked divide-by-2 cells with a sticky-bit cell to identify an overflow condition.