DVI TMDS Data Channel for Green Color

Digital Visual Interface (DVI) relies on Transition-Minimized Differential Signaling (TMDS) to transmit high-speed digital video data from a graphics host to a display. In a standard single-link DVI implementation, the visual signal is divided across three dedicated serial data channels alongside a separate clock signal. This article identifies which specific TMDS data channel is responsible for transmitting green color data and outlines the overall channel mapping used in DVI transmission.

The Green Color TMDS Data Channel

In the DVI specification, TMDS Data Channel 1 carries the green color data.

During the active video display period, 8-bit green pixel components are encoded into 10-bit transition-minimized symbols and serialized across TMDS Data Channel 1 at the pixel clock rate.

DVI TMDS Channel Mapping Breakdown

A single-link DVI connection employs three discrete TMDS data channels (numbered 0 through 2) and one clock channel. Each channel is assigned a specific primary color and control data stream:

  • TMDS Data Channel 0: Carries Blue color data during active video, as well as Horizontal Synchronization (HSync) and Vertical Synchronization (VSync) signals during the blanking intervals.
  • TMDS Data Channel 1: Carries Green color data during active video, along with control signals CTL0 and CTL1 during blanking periods.
  • TMDS Data Channel 2: Carries Red color data during active video, along with control signals CTL2 and CTL3 during blanking periods.
  • TMDS Clock Channel: Carries a dedicated reference clock signal that allows the receiver to synchronize and recover the incoming data streams across all three data channels.

Physical Pinout for TMDS Data Channel 1

On a standard DVI connector (such as DVI-D or DVI-I), TMDS Data Channel 1 utilizes the following differential pair pins:

  • Pin 18: TMDS Data 1+ (positive differential signal)
  • Pin 19: TMDS Data 1- (negative differential signal)
  • Pin 20: TMDS Data 1/3 Shield (ground shield to reduce electromagnetic interference)

In dual-link DVI configurations, a second set of three data channels (Channels 3, 4, and 5) is added to double the available bandwidth for higher resolutions, but TMDS Data Channel 1 remains the primary path for green color data in standard video streams.