To make the audio-visual entertainment experience as natural as possible is one of the major targets of electronic entertainment companies. The journey of televisions from Black & White to plasma and now to LEDs is a fair example of it. High definition digital recording has been made possible through DVDs and Blu-rays. However, to transmit the same quality of high definition data to the display, high quality interface is needed. In pursuit of this life like quality, electronics giants of the world: Sony, Thomson, Panasonic, Toshiba, Phillips and Hitachi, made a joint research group that has given one of the best ways to transmit and access video and audio, HDMI.
Outer Structure



HDMI Connectors


Pin Layout

S.No
|
HDMI Pin Number
|
Function
|
Additional Comments
|
1.
|
Group A (Pins 1-3),
Group B (Pins 4-6),
Group C (Pins 7-9)
|
These pins aid in Transition Minimized Differential Signaling (TMDS). Every group for TMDS signals has 3 pins out serving as positive (1, 4, 7), negative (pins 3, 6, 9) and ground (pins 2, 5, 8).
|
This technology increases up the speed for signal transmission as well as minimizes the interference between the signals. The TMDS signals can carry visual and audio data simultaneously.
|
2.
|
Group D (Pins 10-12)
|
This group of pins aids in syncing the signals sent in the TMDS so that information is transferred in the best and precise manner even if the rate of transmission is high.
|
|
3.
|
Pin 13
CEC(Consumer Electronics Channel)
|
Serves as a communicator between the connected devices, thus acting as a bi-directional control bus.
|
It is an optional feature in HDMI configurations
|
4.
|
Pin14
|
Kept as spare for future purposes
|
|
5.
|
Pin 15
DDC
(Display Data Channel)
|
Utilized to make the output HDMI device send data to input HDMI device.
|
Through this, the devices are synced in terms of video and audio output format.
|
6
|
Pin 16
EDID
(Extended Display Information Data)
|
Used to sync the source and destination device in terms of output quality.
|
For instance, display should be 1080p or 720p and audio should be a 2.1 or 5.1 sound etc. is all synced between the devices through EDID.
|
7
|
Pin 17
|
Provides a shielding for DDC and CEC channels by acting as ground for unwanted signals conveyed through them
|
|
8
|
Pin 18
|
Responsible for supplying power to the HDMI cable which is 5V.
|
|
9
|
Pin 19 (Hot Plug Detect)
|
Facilities simple plug and play facilities for the user.
|
|
Table 1: Table Showing Functions of each of 19 Pins of HDMI Cable
Wiring Section & Conclusion


Filed Under: Insight
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