HDMI Compliance Test Specification (CTS) forms the complete certification standard framework, split into 4 core test layers enforced by all authorized ATC labs, separate from high-level HDMI Forum version specs (2.1 / 2.2).
·Physical Layer CTS (Foundation Test)Verifies transmission eye diagram, jitter, rise/fall time, differential impedance, insertion/return loss. Separate eye templates for 48Gbps (HDMI 2.1) and 96Gbps (HDMI 2.2). Failed physical layer tests block all upper-layer protocol & encryption testing.
·Protocol Layer CTSCovers EDID data parsing/storage, CEA-861 video timing compliance, SCDC I2C communication, CEC device control, ARC/eARC audio channel handshake. SCDC I2C pull-up resistor mismatch & incomplete EDID timing are top protocol layer failure causes.
·HDCP Encryption CTSValidates key burn-in, Source-Sink encryption handshake, stream decryption, key revocation list update, independent from physical/protocol tests yet sequential in lab workflow.
·Cross-Device Interoperability Test (Mandatory ATC Requirement)Pair DUT with mainstream certified TVs/monitors to verify stable pairing, video/audio output, no flicker/disconnect issues; eliminates mass-market customer compatibility complaints despite no standalone official CTS document.
2 Core CTS Differences: HDMI 2.1 vs HDMI 2.2
·Physical layer bandwidth upgrade to 96Gbps FRL, updated equalization & lane calibration limits requiring advanced lab oscilloscope hardware.
·New exclusive CTS test modules: Multi-link dynamic HDR synchronization, LIP Latency Indication Protocol (only mandatory if hardware enables these features).
·Parallel transition policy: 48Gbps devices without HDMI 2.2 exclusive features still certify under HDMI 2.1 CTS throughout 2026. Only native 96Gbps hardware with 12K/16K/LIP functionality enforces HDMI 2.2 CTS full testing.
3 Key Core Sub-Standards Inside Protocol CTS
·EDID Standard: Sink device self-description data covering resolution, refresh rate, HDR/audio support; lab cross-checks EDID binary against product spec sheet & CDF form for full matching.
·CEA-861 Timing Spec: Regulates pixel clock, horizontal/vertical blanking parameters for all video resolutions; out-of-tolerance timing causes display black screen or screen tearing.
·SCDC (Status & Control Data Channel): I2C communication bus for bandwidth negotiation & mode switching; abnormal SCDC traffic leads to intermittent connection failure.
·CEC (Consumer Electronics Control): Cross-device remote control signal transmission, widely prone to cross-brand compatibility defects despite simple test logic.
4 Category-Specific CTS Test Scope Division
·Source (Set-top box, game console): Physical transmit performance, EDID parsing, HDCP encryption, video timing output – no Sink-side receiving/EDID storage tests.
·Sink (TV, monitor): Signal receiving sensitivity, complete EDID storage, HDCP decryption, timing compatibility – no transmission physical layer testing.
·Repeater (AV receiver, splitter): Dual-sided physical layer test, EDID relay verification, HDCP intermediate key transfer, full link equalization – widest test coverage & highest lab cost.
·HDMI Cable: Only physical layer signal integrity (impedance, crosstalk, eye diagram), zero protocol/HDCP testing. Tiered cable specs: Standard < High Speed < Premium High Speed < UHS 48Gbps < UHS 96Gbps Ultra96.Critical cable rules: No standalone cable testing allowed; distinct cable lengths require separate independent certification & Test IDs.
BlueAsia Testing & Compliance Consultant: +86 13534225140 (Benson)
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