Patent ID: 7478011

Claim:
A method for measuring characteristics of an on-chip data signal generated in response to a data clock with period T using on-chip data acquisition circuitry with off-chip data storage and analysis comprising the steps of: a) counting cycles of an asynchronous sample clock signal in a counter; b) generating a digitized sample of the on-chip data signal in response to the asynchronous sample clock signal; c) generating a capture signal synchronous with a first transition of the sample clock signal responsive to a measurement request; d) capturing the digitized sample of the on-chip data signal and a present count value of the counter in a register in response to the capture signal; e) resetting the counter in response to a reset pulse synchronous with a second transition of the sample clock signal following the first transition of the sample clock signal; f) storing a present digitized sample of the on-chip data signal and the present counter value of the register in off-chip storage in response to the capture signal; and g) repeating steps a) to f) a predetermined number N times.