What video resolutions are supported by the DisplayPort RX Subsystem IP (1.2 or 1.4) and can the IP support custom resolutions?
For example, can the DisplayPort 1.2 RX Subsystem IP support a single stream with 3200x1200 pixel frames at 120 fps?
The DisplayPort RX subsystem IP should be able to support any resolution sent by a DP1.2 compliant source and the DisplayPort 1.4 RX subsystem IP should be able to support any resolution (without DSC) sent by a DP1.4 compliant source.
It can support any resolutions which are in the bandwidth mentioned in the related specification.
For example for DisplayPort 1.2:
The maximum lane rate for DP1.2 is 5.4 Gbps.
As it can have up to 4 lanes, the maximum bandwidth is 21.6Gbps.
As the data is 8b/10b encoded, the maximum data rate (or effective bandwidth) for DP1.2 is 17.28Gbps (21.6*8/10 = 17.28Gbps).
The data rate is computed as follow:
Total Horizontal Pixels * Total Vertical Lines * Refresh Rate * Component * Bits per component
Example with 3200*1200 assuming a reduced blanking in RGB (3 components), 8 bits per component:
Total Horizontal Pixels = 3280 (3200 active + 80 blanking)
Total Vertical Lines = 1271 (1200 active + 71 blanking)
Data rate = 3280 * 1271 * 120 * 3 * 8 = 12.006Gbps which is under the DP1.2 maximum data rate when the link is trained with 4 lanes @5.7Gbps.
So the IP should be able to receive this resolution (3200*1200@120Hz).
Note: The resolution needs to be in the EDID in order for a source (TX) to send the resolution.