Tektronix 071-0590-00 Analyzer RX Functions, Automatic Setup Functions Sync, Auto Search Key

Reference

Analyzer (RX) Functions

This section explains how to enable or disable Analyzer automatic synchronization functions. It further shows how to manually set Analyzer input parameters and error detection functions, and how to start tests, view results, and print results. The section also defines all results calculated by the Analyzer.

Automatic Setup Functions (SYNC )

This section explains how to use the following "SYNC" controls and indicator in the ERROR DETECTION section:

AUTO SEARCH key.

DISABLE key.

LOCK indicator.

AUTO SEARCH Key

The AUTO SEARCH key is used to enable or disable the auto-search feature. When auto-search is enabled, the Analyzer will automatically attempt to set the following parameters each time pattern synchronization is lost:

1.clock and data input threshold,

2.data input delay,

3.PRBS pattern,

4.pattern polarity, and

5.pattern alignment.

In addition, auto-search will clear (turn off) the BIT and PHASE history indicators once pattern sync. is regained. Thus, AUTO SEARCH can greatly simplify Analyzer setup and operation, especially when the input clock and data phase relationship and amplitudes are not known.

DISABLE Key

The DISABLE key is used to disable automatic pattern realignment. When automatic pattern realignment is enabled (DISABLE off) the Analyzer will attempt to resynchronize its pattern detector each time BER goes above the pattern synchronization threshold by looking for a new pattern alignment. A change of pattern alignment will occur, for example, if a buffer over flows or under flows in the DUT. A change of pattern alignment will also normally occur if the CLOCK input to the Analyzer is momentarily disconnected.

On the other hand, with pattern realignment disabled (DISABLE on), the Analyzer will not attempt to find a new pattern alignment—even if BER goes above the synchronization threshold —until the start of a new test interval. This allows the analyzer to measure BER and count errors on signals with very high error rates.

GB1400 User Manual 3-19