Tektronix 071-0590-00 user manual Phase

Application Note - Auto Search Synchronization

PHASE

This is a unique and very fast method of determining where the edge of a data bit is in relation with the clock. The determination of phase errors is done by monitoring the logic value of a data bit at the selected threshold voltage and delay at two slightly different times. If the logic value is the same at the two different times, then a phase error has not occurred. This method will work well with any data that is relatively noise, jitter and glitch free.

SYNCHRONIZATION

When we state that “the receiver is synchronized”, we mean that the GB1400 Receiver’s internal reference data pattern generator is bit for bit properly aligned with the incoming data from the device under test. When in synchronization, the receiver can perform a bit for bit check of the incoming data against its internal reference to determine bit errors.

DATA POLARITY

This refers to whether the device under test has inverted the data logic in relation to what was input to it.

DATA EYE

This is a method of showing the data in a visual form. It is displayed on an oscilloscope using the clock as a trigger, and the data into the vertical amplifier. Case 1 of Diagram 1 of this application note is an example of data eye.

GB1400 User Manual 2-39