DisplayPort

/ˈdɪspleɪ pɔːrt/

n. "VESA's royalty-free digital audio/video interface transmitting uncompressed pixel streams over HBR/UHBR lanes."

DisplayPort, short for DisplayPort, delivers high-bandwidth digital video/audio via 1-4 differential pairs (HBR3=32.4Gbps, UHBR20=80Gbps), supporting daisy-chaining, Multi-Stream Transport (MST) for 4x 1080p monitors, and Adaptive Sync (FreeSync). Tunnels through USB4 and competes with HDMI via 128b/132b encoding (DP2.1), enabling 16K@60Hz or 8K@240Hz with DSC compression—uses micro-packet architecture with link training unlike DVI's TMDS.

Key characteristics of DisplayPort include: Micro-Packet Architecture transmits blanking/aux data separately from pixels (HBR3=8.1Gbps/lane x4); UHBR Tiers scale from 10/13.5/20Gbps per lane (DP2.1=77.37Gbps payload); Multi-Stream Transport fans out single cable to 3+ displays via time-division multiplexing; Adaptive-Sync eliminates tearing (FreeSync/G-Sync compatible); Daisy-Chaining connects 6+ monitors without hub using DP-in/DP-out ports.

Conceptual example of DisplayPort usage:

/* DP 2.1 Link Training - UHBR20 negotiation */
struct dp_link_training {
    uint8_t voltage_swing;      // 0-3 (400-1200mV)
    uint8_t pre_emphasis;       // 0-3 (0-3.5dB)
    uint8_t post_cursor;        // DFE taps
    bool uhbr20_trained;        // 20Gbps/lane success
};

void dp_lt_train(struct dp_link_training *lt) {
    // Training Pattern 1: Swing/emphasis sweep
    for (lt->voltage_swing = 0; swing < 4; swing++) {
        send_tp1_pattern();
        if (rx_eq_satisfied()) break;
    }
    // TP2: Channel equalization with DFE
    send_tp2_pattern();
    lt->uhbr20_trained = check_ber_lt_1e-8();
    
    // Final: Main stream attributes (MSA)
    set_msa(3840, 2160, 60, 8);  // 4K@60 8bpc
}

Conceptually, DisplayPort streams raw RGB pixels + audio + sideband messages over HBR/UHBR lanes with link training optimizing CTLE/DFE taps per cable length—MST branches one PHY to office monitor daisy-chain while USB4 tunnels DP1.4 inside 40Gbps pipe for laptop docking. Stress-tested via PRBS/LFSR generators hitting 1e-12 BER, with DP80 cables mandatory for UHBR20 unlike HDMI's license walls.