A special application is conformance testing in line with the standard’s compliance test specification (CTS) as a final interoperability test. Before a device fitted with an HDMI or MHL port is introduced to the market, it must first be checked by an authorized test center (ATC) to verify that its functionality conforms to the CTS. Tests are not just conducted at the protocol level but also on the physical layer, with separate tests for sinks (TVs), sources (set-top boxes) and cables.
The tests carried out during the certification process are both time-consuming and costly. If errors are found during certification, the entire test has to be repeated. It therefore makes sense to conduct tests using suitable T&M equipment capable of assuring devices’ quality prior to the certification process.
To certify consumer electronics equipment in a lab or to conduct advance assessments, protocol tests must be carried out as described in detail in the standards under specific test IDs. The section headings in the CTS correspond to the test ID numbers. Figure 3
shows the system tests specified in MHL.
Figure 3: Raw TMDS data is analyzed for system tests conducted in accordance with the compliance test specification (CTS)