Using the High Speed Adapter with the Digital Discovery

The Digital Discovery is a combined logic analyzer and pattern generator instrument designed to allow you to debug, visualize, and simulate digital signals for most embedded projects. The High Speed Adapter and impedance-matched probes can be paired with the Digital Discovery to measure up to 800 MS/s with the logic analyzer.

Digital Discovery with the High Speed Adapter and Logic Probes

Inventory

The following materials are used with this tutorial:

Background

The high speed adapter with twisted wires provides proper termination, improved bandwidth, and noise reduction to enable Digital Discovery to take higher resolution measurements. This is highly recommended for observing high speed signals exceeding 100 MHz or to look at signal phase with better than 10 ns of resolution.

Demonstration

  1. Connect the high speed adapter to the 2×16 High-Speed Inputs connector on the Digital Discovery. The adapter is not keyed so either orientation can be used. Note that if you are following the pin adapter diagram from the Digital Discovery Reference Manual, the pin labels may not match the ones used in tutorials on the High-Speed Adapter if it is not oriented in the same direction.
  2.  High Speed Adapter next to the Digital Discovery  High Speed Adapter attached to the Digital Discovery  High Speed Adapter attached to the Digital Discovery
  3. Attach the 2×1 housing side of the twisted wire pairs to the the adapter. The black wires will need to be attached to the grounded pins on the high-speed adapter, located on the outer rows on the high speed adapter, as the red wires have an embedded 100 Ohm series resistor.
  4.  High Speed Adapter attached to the Digital Discovery  High Speed Adapter attached to the Digital Discovery
  5. Attach the other end of the twisted wire pairs with the embedded 100 Ohm resistor (red wire) to the device under test.
  6. Twisted Logic Probe wires attached to a set of FPGA pins

In the WaveForms software, a selection of high-speed pin groups are available to choose from in the upper right-hand corner of the WaveForms GUI. Currently, only these pins can be chosen for high speed inputs.

WaveForms Preset Options for High Speed Inputs (click to enlarge)

The Digital Discovery with the High-Speed Adapter can be further explored by following the Decoding VGA Signals With a Portable Logic Analyzer project.