User Guide

Functional Description
Microsemi Proprietary and Confidential UG0935 User Guide Revision 2.0 5
3 Functional Description
3.1 HPD
DisplayPort Tx IP detects Hot Plug Detect (HPD) assertion, de-assertion, and HPD interrupt event. It
reports the HPD event through an interrupt. After HPD assertion, which means a DisplayPort monitor is
connected, DisplayPort Source application software should start the training procedure.
DisplayPort Rx IP outputs HPD signal according to DisplayPort Sink application software settings. After
DisplayPort Rx IP is ready, DisplayPort Sink application software should set the HPD signal to 1. When it
expects the DisplayPort Source device to re-read Sink device status or re-training, DisplayPort Sink
application software should set an HPD to generate the HPD interrupt signal.
3.2 AUX Channel
DisplayPort Source and Sink device communicate through an AUX Channel. Source device sending
request transaction to the Sink device and the Sink device sending Reply transaction to Source Device.
DisplayPort Tx and Rx IP implements the AUX transaction transmitter and receiver. For AUX transaction
transmitter, DisplayPort Source or Sink application software provides all AUX transaction content bytes,
DisplayPort Tx and Rx IP generate the transaction bitstream. For the AUX transaction receiver,
DisplayPort Tx and Rx IP receive the transaction and extract all bytes to DisplayPort application
software.
The Link Policy Maker and Stream Policy Maker should be implemented in the DisplayPort application
software.
3.3 Video Stream Transmission
DisplayPort Tx and Rx IP supports 8 bpc RGB/YCbCr 4:4:4, and only supports a single video stream.
After training is done and the video stream is ready, DisplayPort Tx IP and RX IP start to transmit video
stream.
DisplayPort Source application software should configure the video stream attribute MSA and enable
DisplayPort Tx IP video transmission. The VSC packet is not supported. DisplayPort Tx and Rx IP are
using MISC0 and MISC1 in MSA for Pixel Encoding/Colorimetry Format Indication.
After training, DisplayPort Rx IP should be enabled for video receive. DisplayPort Rx IP gets the received
MSA and sets the recovery video format parameter to let DisplayPort Rx IP output the correct video
stream signal.
DisplayPort Tx and Rx IP support synchronous video clock mode and asynchronous video clock mode.
For synchronous video clock mode, Mvid and Nvid are fixed value in MSA, DisplayPort Source
application software should set Mvid and Nvid. For asynchronous video clock mode, Nvid is fixed and
configured by software. The user needs to generate Mvid and send Mvid to DisplayPort Tx IP.
DisplayPort Rx IP does not include a video clock recovery function. The user should recovery the video
clock outside DisplayPort Rx IP or use a fixed high enough frequency clock to output video stream data.