Measuring setup and hold times using a virtual delay

An apparatus comprising:

• a first digital frequency divider having an input and an output, the input of the first digital frequency divider receiving a first signal indicating an oscillating signal with a first delay;
• a second digital frequency divider having an input and output, the input of the second digital frequency divider receiving a second signal indicating the oscillating signal with a second delay;
• and
• a flip-flop having an input and an output, wherein the input of the flip-flop is coupled to the output of the second digital frequency divider and a data signal and clock signal for measuring a set-up time, hold time, or a combination thereof of a device under test are generated based on a signal of the output of the first digital frequency divider and a signal of the output of the flip-flop, respectively.

An apparatus comprising:

• a device under test having a data input, clock input, and output;
• and
• a test circuit having an input coupled to the output of the device under test and first and second outputs coupled the data and clock inputs, respectively, the test circuit comprising:
• a first digital frequency divider having an input and an output, the input of the first digital frequency divider receiving a first signal indicating an oscillating signal with a first delay;
• a second digital frequency divider having an input and output, the input of the second digital frequency divider receiving a second signal indicating the oscillating signal with a second delay;
• and
• a flip-flop having an input and an output, wherein the input of the flip-flop is coupled to the output of the second digital frequency divider, wherein a data signal and clock signal for measuring a set-up time, hold time, or a combination thereof of the device under test are generated on the first and second outputs of the test circuit and the data and clock signals are based on a signal of the output of the first digital frequency divider and a signal of the output of the flip-flop, respectively.