Product guide

Description
XAPP1178 (v2.0) January 23, 2015 www.xilinx.com 11
DisplayPort Transmitter Software Drivers
The software application provided in this application note is built upon the DisplayPort
transmitter drivers which has the link policy maker and stream policy maker features
implemented. Local driver repository (v3.0) provided in the application package overwrites the
DisplayPort drivers (v2.0) that exist in the Vivado Design Suite. DisplayPort drivers also use the
common video libraries present with the DP drivers. The complete API details of the drivers and
their usage are provided in the XAPP package:
DP_Tx_Xapp/common/driver_repo/drivers/dptx_v3_0/doc/html/api/index.html
Note that the XDptx_VideoMode structure is renamed to XVid_VideoMode and is placed under
the common video libraries. The XDptx_DmtMode structure is renamed to
XVid_VideoTimingMode and is placed under the common video libraries.
Refer to the updated software drivers documented with Doxygen and available with SDK tool.
Summary
The DisplayPort transmitter (DPTX) bare-metal software (SW) driver follows the VESA
DisplayPort 1.2a specification. The following functionality is provided by the DPTX driver:
• AUX channel device and link services:
°
Read/writes from an RX device DisplayPort Configuration Data (DPCD) using the AUX
channel.
°
Reads from a RX sink Extended Display Identification Data (EDID) using I2C-over-AUX
reads.
• Link policy maker (LPM)
• Stream policy maker (SPM)
• Hot-plug-detect (HPD) handling
• Multi-stream transport (MST) support using sideband messaging
• Topology manager
• Payload bandwidth management
AUX Channel Device and Link Services
The auxiliary (AUX) channel communication allows communication between the DPTX and a DP
receiver (DPRX) without needing the main link to be trained. This allows the DPTX to determine
a DPRX capabilities and status, and to configure and control it.
The SW driver allows the following AUX channel and device link services: