DPA-400 AUX Monitor


DisplayPort™ AUX Channel Monitor

DPA-400 with the AUX Channel Monitor GUI provide a compact, pocket sized tool for recording and analyzing DisplayPort AUX channel traffic. They enable the user to monitor, capture and document the DPCD reads and writes and the MST Sideband Channel Communication over a DP link. Compatible with all DP versions from DP 1.1 to 1.4 and HDCP 1.3 and 2.2 messaging. DPA-400 is also compatible with DisplayPort Alternate Mode in USB Type-C interface.

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An Essential Tool

Unigraf AUX Channel Monitor is an almost mandatory tool for any engineer verifying or debugging Compliance Test or Interoperability Test results. Only by analyzing the details of the source – sink interaction the designer is able to fully confirm the behavior of both parties. When the content of each read and write are available in detail, there will be no room for guessing.


Raw and Parsed Message Data

DPA-400 GUI parses all data captured from the AUX Channel traffic. This makes it straightforward for the engineer to follow the Sink / Source communication, the CTS test execution and refer it to the requirement of the standard. AUX Channel Monitor GUI lists every AUX Channel events and DPCD content both as as time stamped raw data and in a parsed form. The details are explained with the same terminology used by the relevant VESA standard and Unigraf CTS Test report. The complete logs can also be stored for later use or shared with colleagues as universally portable HTML files.

Compatible to DP 1.0 to DP 1.4 and
HDCP 1.3 and 2.2

DPA-400 GUI detects and parses all DPCD locations used in DP versions 1.0, 1.1, 1.2, 1.3 and 1.4. It decodes as well the HDCP 1.3 and 2.2 messages and DP Sideband Channel Communication messages. The activity of the Hot Plug Detect (HPD) signal and optional user defined input signals will also be tracked and time stamped. 

USB-C DisplayPort Alt Mode

With the special, Unigraf provided cable you can attach DPA-400 directly between any two USB Type-C enabled devices and monitor DisplayPort Alt Mode related AUX Channel message transaction.

Easy to Use

DPA-400 is a small sized, USB-powered device. It measures only 10.5×13×3.5 centimeters. The compact size and light weight makes it an ideal tool for a laboratory desktop. It is a snappy companion to a compatible laptop computer or tablet.

Unigraf AUX Channel Monitor affects the signal quality as little as possible. DPA-400 delivery includes a custom cable for bypassing the main stream lane signals. This ensures that the signal integrity of the high speed bus will not be compromised with monitoring.


  • Compatible with all DP versions
  • Device independent
  • Data interpreter with time stamps
  • Detect and parse all DPCD locations
  • Decode the Sideband CH Communication messages
  • Pocket Size
  • USB controlled and powered


  • Silicon validation
  • Software debug and validation
  • Resolve interoperatibility problems
  • Monitoring and time measurement of events