DisplayPort Intel® FPGA IP User Guide

ID 683273
Date 1/24/2022
Public

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Document Table of Contents

9.71. btc_dptxll_hpd_irq

Prototype:

int btc_dptxll_hpd_irq(BYTE tx_idx)

Thread-safe:

No

Available from ISR:

Yes

Include:

< btc_dptxll_syslib.h >

Return:

0 = success, 1 = fail

Parameters:

tx_idx—Source instance index (0 - 3)

Description:

This function handles an HPD_IRQ. Must be invoked every time an HPD_IRQ is detected.

Example:

btc_dptxll_hpd_irq(0);

When btc_dptxll_hpd_change(1) is invoked and an MST capable DisplayPort sink device is detected, the topology discovery process is started automatically.

The process performs the following steps:
  • Assigns a new GUID to sinks without one.
  • Traverses all the topology connected through the DisplayPort sink.
  • Adds each port found to the list of discovered ports.
  • For each output port with plug status asserted and messaging capabilities, collects full and available PBN.
  • Clears the sink VCP ID Table.
  • Enables MST framing.