Mechanism for measuring read current variability of SRAM cells

An integrated circuit comprising:

• a static random access memory (SRAM) array including a plurality of SRAM cells;
• a selection circuit coupled to the SRAM array and configured to select a particular SRAM cell of the plurality of SRAM cells in response to a selection input;
• an oscillator circuit coupled to receive a signal indicative of a read current of a selected SRAM cell of the SRAM array, and configured to oscillate at a frequency that is dependent upon the read current of the selected SRAM cell during operation in a first mode;
• wherein the oscillator circuit is further configured to oscillate at a frequency that is dependent upon a current established within the oscillator circuit and irrespective of the read current of the selected SRAM cell during operation in a second mode in response to assertion of a bypass control signal;
• and
• a frequency determining circuit coupled to the oscillator circuit and configured to output a value corresponding to the frequency of oscillation of the oscillator circuit.

A method comprising:

• executing a read current test of a static random access memory (SRAM) array within an integrated circuit, wherein executing the read current test comprises:
• writing a value to at least a portion of a plurality of SRAM cells in the SRAM array;
• a selection circuit selecting a particular SRAM cell;
• an oscillator circuit receiving a signal indicative of a read current of a selected SRAM cell of the plurality of SRAM cells, and oscillating at a frequency that is dependent upon the read current of the selected SRAM cell during operation in a first mode;
• the oscillator circuit oscillating at a frequency that is dependent upon a current established within the oscillator circuit and irrespective of the read current of the selected SRAM cell during operation in a second mode in response to assertion of a bypass control signal;
• and
• a frequency determining circuit outputting a value corresponding to the frequency of oscillation of the oscillator circuit.