182 Chapter 10 Testing EDID
2. Press and hold the R key and then press and release the ACS key. Alternatively power
off the generator, press and hold both the R and ACS keys then power up the generator
to configure the generator knob list with the hot plug formats.
The initial compliance test screen re-appears and the Format knob list includes only
those formats in the display EDID.
Visual verification of formats
Additional visual inspection of Tests 8-19 and 8-20 is necessary to ensure that each
format can be loaded and displayed at each pixel encoding and at its minimum and
maximum pixel rate.
Test ID 8-19 involves testing each format with different YCbCr pixel encoding: 4:4:4 pixel
sampling and 4:2:2 sampling. Test ID 8-20 requires that each format listed in the EDID be
be tested at two different pixel clock frequencies. The two different frequencies shall be the
minimum and maximum permitted by a Source. For 50Hz formats, these values are
49.75Hz and 50.25Hz (50Hz ± 0.5%). For 59.94Hz or 60Hz formats, these frequencies are
59.64Hz (59.94Hz – 0.5%) and 60.3Hz (60Hz + 0.5%). The tested pixel clock frequency
accuracy shall be ±0.05%.
A separate listing of the formats is provided on the Format knob list to support this visual
inspection testing. The nomenclature for visual inspection testing of maximum and
minimum pixel rate is of the form shown in the example below: