DVI Port DDC Serial Data Pin Designation

This article provides a direct overview of the pin configuration for the Digital Visual Interface (DVI) standard, focusing specifically on the Display Data Channel (DDC). Readers will identify the exact pin designation for the DDC serial data line, understand its electrical function within the I²C communication bus, and learn about the complementary pins required for display identification.

DDC Serial Data Pin

On a standard DVI connector (including DVI-D, DVI-I, and DVI-A variants), the pin designation for the DDC serial data line (SDA) is Pin 7.

Function of the DDC Data Line

Pin 7 serves as the bidirectional data pathway for the Display Data Channel. Based on the I²C serial communication protocol, this line allows the graphics card (host) and the display device to exchange configuration information.

The primary purpose of this connection is to transmit Extended Display Identification Data (EDID). Through Pin 7, the display communicates its supported resolutions, refresh rates, native pixel timing, color capabilities, and manufacturer specifications back to the computer, enabling automatic Plug-and-Play setup.

For the DDC serial data line to function, it operates alongside several supporting pins within the standard 24-pin DVI grid:

  • Pin 6 (DDC Clock / SCL): Carries the I²C serial clock signal generated by the host to synchronize data transmission.
  • Pin 14 (+5V Power): Delivers standby power from the host to the display's EDID EEPROM, enabling the computer to query the display's identity even if the monitor is powered off.
  • Pin 15 (Ground): Acts as the signal ground reference for the +5V power line and the DDC data and clock signals.

This four-wire sub-circuit (Pins 6, 7, 14, and 15) remains identical across single-link and dual-link DVI implementations, ensuring universal backward compatibility across all DVI-compliant monitors and source devices.