Facts : 1 E-DDC Enhanced Display Data Channel (E-DDC) is the most recent revision of the DDC standardbr Facts : 2 Version 1 was introduced in September 1999 and featured the addition of a segment pointer which allowed up to 32 Kbytes of display information storage for use by the Enhanced EDID (E-EDID) standardbr Facts : 3 Earlier DDC implementations used simple 8-bit data offset when communicating with the EDID memory in the monitor, limiting the storage size to 2 bytes = 256 bytes, but allowing the use of cheap 2-Kbit EEPROMsbr Facts : 4 However, VESA specification defines the segment index value range as 00h to 7Fh, so this only allows addressing 128 segments * 256 bytes = 32KBbr Facts : 5 The segment index register is volatile, defaulting to zero and automatically resetting to zero after each NACK or STOPbr Facts : 6 Therefore, it must be set every time access to data above the first 256-byte segment is performedbr Facts : 7 The auto-reset mechanism is to provide for backward compatibility to, for example, DDC2B hosts, otherwise they may be stuck at a segment other than 00h in some rare casesbr Facts : 8 Other important changes were removal of the DDC1 and DDC2Ab protocols, deprecation of separate VESA P&D and FPDI device addresses, and clarifications to the DDC power requirementsbr Facts : 9 E-DDC Version 1.1, approved March 2004, featured support for HDMI and consumer electronicsbr Facts : 10 E-DDC Version 1.