ATE timing measurement unit and method

A real-time results processor for implementation in a semiconductor tester pin electronics channel for detecting actual timing data relating to test waveforms generated by a semiconductor tester, said real time results Processor including:

• input circuitry having a clock input for receiving a stream of data sampled from said test waveforms;
• a data filter coupled to said input circuitry and including logic responsive to preprogrammed criteria to extract data indicative of a timing event;
• a counter operative to count said data values and generate a count representative of the timing of said extracted timing event data, the counter including a rollover input set to roll the counter over according to the clock input;
• and
• storage circuitry for storing said count.

A method of determining the length of a transmission line, said method including the steps of:

• driving a periodic waveform of a predetermined magnitude along said transmission line at a predetermined waveform period to generate a periodic sequence of incidence edges and reflected edges;
• setting a comparator detection threshold at a specified level to detect said incidence edges;
• strobing said waveform at a strobe period, said strobe period and waveform period having edges that periodically coincide to define a beat period;
• establishing a timing reference point on said waveform;
• detecting one of said incidence edges at an incidence edge detection point in a first search and recording a count of the number of strobes from said timing reference point to said incidence edge detection point;
• resetting said count at said beat period rate to maintain said timing reference point;
• detecting said reflected edge in a subsequent search and recording a count of the number of strobes from said timing reference point to said reflected edge detection point;
• and
• evaluating the relative counts between said incidence edge detection point and said reflected edge detection point to determine the length of said transmission line.

A method of determining, in parallel, the Pulse widths for a plurality of periodic tester waveforms generated by a plurality of tester channels, each of said channels simultaneously carrying out the steps of:

• driving a fixed reference rising edge at a predetermined period;
• selecting a first timing vernier step delay to generate a falling edge waveform;
• combining said fixed reference rising edge and said falling edge to generate a first desired pulse width;
• detecting the actual pulse width;
• repeating said driving, selecting, combining and detecting steps with subsequent vernier settings to generate detected pulse width data;
• and
• characterizing said timing vernier with said detected pulse width data.