Tektronix 071-0590-00 Single-ended or Differential Operation, Pattern Sync and CLOCK/4 Outputs

Reference

Single-ended or Differential Operation

DATA-BAR and CLOCK-BAR are complimentary outputs to DATA and CLOCK respectively. Therefore, to drive a single-ended clock or data input simply connect appropriate true output (CLOCK or DATA) while terminating its compliment (CLOCK-BAR or DATA-BAR) with 50 Ohms to ground. Or, to drive a differential clock or data input, connect the appropriate true output (CLOCK or DATA) to the non-inverting input and the complimentary output (CLOCK-BAR or DATA-BAR) to the inverting input. No other setup is required to configure the Generator for singled-ended or differential operation.

Procedure for Single-ended Operation (TX only)

1.For singled-ended operation, connect Generator CLOCK and DATA outputs to singled-ended inputs on the DUT.

2.Terminate the CLOCK-BAR and DATA-BAR outputs with 50 Ohms to ground.

Procedure for Differential Operation (TX only)

1.Connect CLOCK and CLOCK-BAR outputs of the Generator to the true and complimentary clock inputs on the DUT.

2.Connect DATA and DATA-BAR outputs of the Generator to the true and complimentary data inputs on the DUT.

Pattern Sync and CLOCK/4 Outputs

The OUTPUT section of the Generator front panel contains two additional outputs that may be useful when observing the Generator output with an oscilloscope. The first is the Pattern Sync or output which generates one pulse per pattern frame. This signal may be used to trigger an oscilloscope at the beginning of the output data pattern. The second is the CLOCK/4 output, which is a clock signal at one quarter the frequency of CLOCK. This signal is particularly useful when viewing the output of the Generator using an oscilloscope that doesn't have sufficient bandwidth to trigger on the CLOCK signal.

Both the Pattern Sync and CLOCK/4 outputs have a fixed amplitude of 200 mV pk-pk, centered around ground, when terminated by 50 Ohms to ground. The phase relationship of CLOCK/4 and CLOCK is also fixed, with the nominal location of CLOCK/4 transitions occurring on the falling edge of CLOCK.

The width and location of the Pattern Sync pulse depends on which pattern type is currently active. For PRBS patterns, the Pattern Sync pulse has a width equal to one bit time slot, at a fixed position not adjustable by the user. For short- WORD patterns (1-Mbit Option not installed) the Pattern Sync waveform is a nominal square wave that is high during the first byte of a 16-bit WORD, and low for the second. For long-WORD patterns (1-Mbit Option installed), the Pattern Sync pulse is one byte wide that occurs at the beginning of the frame.

3-16 GB1400 User Manual