Mapping variations in local temperature and local power supply voltage that are present during operation of an integrated circuit

A method comprising:

• providing an integrated circuit (IC) having a plurality of oscillators at distributed locations in the IC;
• determining a respective rate of oscillation of each of the oscillators;
• and
• detecting variations in local power supply voltage in the IC based on the determined rates of oscillation.

A method comprising:

• providing an integrated circuit (IC) having a plurality of pairs of oscillators, the two oscillators of each pair of oscillators being located adjacent to each other, the pairs of oscillators being at distributed locations in the IC;
• determining a respective rate of oscillation of each of the oscillators;
• and
• detecting variations in local temperature in the IC and variations in local power supply voltage in the IC based on the determined rates of oscillation.

A test apparatus comprising:

• a processor;
• an input interface coupled to the processor, the input interface to couple to a test access port of a device under test (DUT) to receive oscillation rate data indicative of a respective rate of oscillation of each of a plurality of oscillators at distributed locations of the DUT;
• a memory coupled to the input interface and to the processor to store the oscillation rate data received by the input interface;
• and
• a control interface coupled to the processor, the control interface to couple to the DUT to exercise the DUT;
• wherein the processor is programmed to derive, based on the oscillation rate data stored in the memory, results data indicative of at least one of (a) variations in the local temperature in the DUT, and (b) variations in local power supply voltage in the DUT.

A method comprising:

• providing an integrated circuit (IC) having an oscillator formed thereon;
• performing a calibration procedure to determine a function by which a rate of oscillation of the oscillator varies in dependence on changes in local power supply voltage;
• detecting a respective rate of oscillation of the oscillator at each of a sequence of points in time;
• and
• detecting a transient change in the local power supply voltage based on the detected respective rates of oscillation of the oscillator at the sequence of points in time.

An apparatus comprising:

• a storage medium having stored thereon instructions that when executed by a machine result in the following:
• receiving oscillation rate data indicative of a respective rate of oscillation of each of a plurality of oscillators at distributed locations of a device under test (DUT);
• storing the received oscillation rate data in a memory;
• and
• deriving, based on the stored oscillation data, results data indicative of at least one of (a) variations in the local temperature in the DUT, and (b) variations in local power supply voltage in the DUT.