EDID 的介绍课程

EDID IntroductionContent❑1.What is EDID ?❑2.Data Formats❑3.I²C Bus❑4.Result of EDID Measuring❑5.F/D Measure1. What is EDID?EDID => Extended Display Identification DataThe EDID includesmanufacturer name ; product type ; timings supported by the display ;display size ; luminance data ;Pixel mapping data(for digital display only) ;Computer DisplayGraphics CardEDIDEDID is Defined by a standard published by the Video Electronics Standard Association (VESA)VESA Video Electronics Standard Association視訊電子標準協會VESA is an organization that supports and sets industry-wide interface standards for the PC, workstation, and consumer electronics industries.BenQ 19”!!EDID簡單的說: EDID 能使個人電腦知道現在連接的顯示器是哪一家廠商,螢幕大小,解析度多少, 等…..For example, here is a summary of the data reported by an Envision EN-775e monitor:010101012.1 EDID Data Formats:128 bytesEDID Structure 1.0 –was defined in 1994EDID Structure 1.1 –was defined in 1996EDID Structure 1.2 –was defined in 2000EDID Structure 1.3 –was defined in 2000256 bytesEDID Structure 2.0 –defines a new 256-byte structure2.2 EDID Formats Overview•ID Manufacturer Name/ID Product NameID Serial Number/Week,Year of Manufacture•EDID Version/Revision (Binary)•Video input DefinitionMax Horizontal/Vertical Image sizeFeature Support2.2.1Header(8 bytes)2.2.2Vendor/Product ID(10 bytes)此表格為固定格式2.2.2-1ID Manufacturer Name/ID Product Code(2 bytes)2.2.2-2ID Serial Number(4 bytes)EX1: Dell0001000010101100001000010101100DEL 10ACHex BinaryEX2: IBM0010010001001101010010001001101IBM 244DHex Binary2.2.2-3Week of Manufacture(1byte)2.2.2-4Year of Manufacture(1byte)The Week of Manufacture field ,if used , set to a value in the range of 1~53If not used , the value should be set to 0Value stored = Year of manufacture –19902.2.3EDID Structure Version / Reversion (2 bytes)0A 10 HexBinaryValue00001010EX1: Week of manufacture = 10 EX2: Year of manufacture = 1995 0505Hex Binary Value 000001010101Hex Binary Value 00000001EX3: EDID Structure version = 12.2.4Basic Display Parameters and Features(5 bytes)2.2.4-1Video input definition(1 bytes)EX1: Bit6 Bit5= 0 00.700 , 0.300 (1.000Vp-p)EX2: 00001000it means:Analog Input ,1.0Vp-p,separate syncs2.2.4-2Max Horizontal/Vertical Image size(1 byte)2.2.4-3Display Transfer Characteristic -Gamma(1 byte)Value stored = (gamma x 100) –100EX: a gamma value of 2.8 would be represented as 18040 28Hex ValueBinary 00101000 EX1: Max H Image size = 40cm180 ValueEX1: Display Gamma = 2.8B4Hex Binary 101101002.2.4-4Feature Support(1 bytes)EX1: 11001000it means:Standby ,Suspend ,RGB ColorEX2: 11101111it means:Standby ,Suspend ,RGB Color ,sRGB supported ,Referred Timing ,Default GTF support2.2.5Color Characteristics(10 bytes)EX1: Rx = 0.3400.340 x 2 = 0.6800.680 x 2 = 1.3600.360 x 2 = 0.7200.720 x 2 = 1.4400.440 x 2 = 0.8800.880 x 2 = 1.7600.760 x 2 = 1.5200.520 x 2 = 1.0400.040 x 2 = 0.0800.080 x 2 = 0.160010*******2.2.6 EDID Established Timing Section(3 bytes)Indicate support for established VESA and other common timings in a very compact formEX1: Established timing 1 = 10100101 =A5it means established timing720x400 @70Hz640x480 @60Hz640x480 @75Hz800x600 @60HzEX2: Established timing 2 = 11001111 =CFit means established timing800x600 @72Hz,75Hz1024x768 @60Hz,70Hz,75Hz1280x1024 @75Hz2.2.7 Standard Timing Identification(16 bytes)The next 16 bytes provide identification for up to eight additional timings,Each identified by a unique 2-byte code derived from the mode format and fresh rateUnused fields in this section shall be set to 01h,01hEX1: 10101001 A901000000 40It means 1600x1200 @ 60Hz(1600/8)-31 = 169 = 10101001(Bin)60-60= 0 = 00000(Bin)1600:1200 = 4:3 = 01(Bin)The Range of horizontal active pixels Is 256 2288EX2: Why H-Range is 256~2288 ?? Min:00000001=11+31=3232x8=256Max:11111111=255255+31=286286x8=22882.2.8.1 Detailed Timing Descriptions(72bytes)The detailed timing block is divided into four descriptors which are 18 bytes eachEX1: Pixel Clock=135M Hz135M / 10000 = 1350013500 = 0011010010111100 = 34h,BChstored as BCh,34hEX2: Horizontal pixels = 000000001100000001010001Horizontal Active Pixels0101+00000000=010*********=1280 pixelsHorizontal Blanking Pixels0001+11000000=000111000000= 448 pixels2.2.8.2 Detailed Timing Descriptions(72bytes)The detailed timing block is divided into four descriptors which are 18 bytes each EX3: Horizontal sync. Offset = 18 pixels = 00010010(bin)Horizontal sync. Width = 108 pixels = 01101100(bin)Vertical sync. Offset = 38 lines = 00100110(bin)Vertical sync. Width = 2 lines = 00000010(bin)Byte 1 00010010 (H-sync. Offset lower 8 bits)Byte 2 01101100 (H-sync.Width lower 8 bits)Byte 3 01100010 (V-sync Offset lower 4 bits + V-sync Width lower 4 bits)Byte 4 00001000 (H-sync Offset upper 2 bits + H-sync Width upper 2 bits +V-sync Offset upper 2 bits + V-sync Width upper 2 bits) EX4: H image size = 380 mm = 101111100(bin)V image size = 290 mm = 100100010(bin)Byte 1 01111100 (H image size lower 8 bits)Byte 2 00100010 (V image size lower 8 bits)Byte 3 00010001 (H image size upper 4 bits + V image size upper 4 bits)2.2.9 Monitor Descriptor Description(18 bytes)2.2.9.1 Tag definitions2.2.10 Extension Flag and Checksum(2 bytes)3.1 The channelThe channel for transmitting the EDID from the display to the graphics card Is usually the I²C Bus3.2 What is I²CI²C(for Inter-integrated Circuit) is a serial computer bus invented by Phililps. I²C uses only two bi-direction lines,clock and data .3.2 EEPROM Spec:I²C Start & Stop Condition I²C Data is transmitted Changing the SDA line , While the SCL line is high ,A start or stop is recognized .Changing the SDA line , While the SCL line is low , Data is transmitted .3.3 EEPROM Spec:Recommend Operating Conditions4.1 EEPROM Spec: Write OperationCurrent Address Read4.2 PCB-Test 燒錄量測: (隨機燒錄一個程式)128 Bytes(8bits)4.2-1 EDID燒錄量測:(燒錄128個FF)4.2-2 EDID 燒錄量測: (燒錄1個AA)4.2-3 EDID 燒錄量測: (燒錄1個00)Result of EDID Measuring 4.2-4 EDID 燒錄量測: (燒錄5個00)。