Extended Display Identification Data - EDID 1.3 Data Format

EDID 1.3 Data Format

EDID structure, version 1.3
Bytes Description
0–19 Header information
0–7 Fixed header pattern: 00 FF FF FF FF FF FF 00
8–9 Manufacturer EISA ID. Encoded as 3 5-bit letters (1=A, 26=Z), big-endian, with msbit reserved.
Bit 15 (Reserved, always 0)
Bits 14–10 First letter of manufacturer ID (byte 8, bits 6–2)
Bits 9–5 Second letter of manufacturer ID (byte 8, bit 1 through byte 9 bit 5)
Bits 4–0 Third letter of manufacturer ID (byte 9 bits 4–0)
10–11 Manufacturer product code. 16-bit number, little-endian.
12–15 Serial number. 32 bits, little endian.
16 Week of manufacture. Week numbering is not consistent between manufacturers.
17 Year of manufacture, less 1990. (1990–2245). If week=255, it is the model year instead.
18 EDID version, usually 1 (for 1.3)
19 EDID revision, usually 3 (for 1.3)
20–24 Basic display parameters.
20 Video input parameters bitmap
Bit 7=1 Digital input. If set, the following bit definitions apply:
Bits 6–1 Reserved, must be 0
Bit 0 Signal is compatible with VESA DFP 1.x TMDS CRGB, 1 pixel per clock, up to 8 bits per color, MSB aligned,
Bit 7=0 Analog input. If clear, the following bit definitions apply:
Bits 6–5 Video white and sync levels, relative to blank: 00=+0.7/−0.3 V; 01=+0.714/−0.286 V; 10=+1.0/−0.4 V; 11=+0.7/0 V
Bit 4 Blank-to-black setup (pedestal) expected
Bit 3 Separate sync supported
Bit 2 Composite sync (on HSync) supported
Bit 1 Sync on green supported
Bit 0 VSync pulse must be serrated when composite or sync-on-green is used.
21 Maximum horizontal image size, in centimetres (max 292 cm/115 in at 16:9 aspect ratio)
22 Maximum vertical image size, in centimetres. If either byte is 0, undefined (e.g. projector)
23 Display gamma, datavalue = (gamma*100)-100 (range 1.00–3.54)
24 Supported features bitmap
Bit 7 DPMS standby supported
Bit 6 DPMS suspend supported
Bit 5 DPMS active-off supported
Bits 4–3 Display type (digital): 00 = RGB 4:4:4; 01 = RGB 4:4:4 + YCrCb 4:4:4; 10 = RGB 4:4:4 + YCrCb 4:2:2; 11 = RGB 4:4:4 + YCrCb 4:4:4 + YCrCb 4:2:2
Bits 4-3 Display type (analog): 00 = Monochrome or Grayscale; 01 = RGB color; 10 = Non-RGB color; 11 = Undefined
Bit 2 Standard sRGB colour space. Bytes 25–34 must contain sRGB standard values.
Bit 1 Preferred timing mode specified in descriptor block 1.
Bit 0 GTF supported with default parameter values.
25–34 Chromaticity coordinates.
10-bit CIE xy coordinates for red, green, blue, and white. .
25 Red and green least-significant bits
Bits 7–6 Red x value least-significant 2 bits
Bits 5–4 Red y value least-significant 2 bits
Bits 3–2 Green x value least-significant 2 bits
Bits 1–0 Green y value least-significant 2 bits
26 Blue and white least-significant 2 bits
27 Red x value most significant 8 bits. 0–255 encodes 0–0.996 (255/256); 0–0.999 (1023/1024) with lsbits
28 Red y value most significant 8 bits
29–30 Green x and y value most significant 8 bits
31–32 Blue x and y value most significant 8 bits
33–34 Default white point x and y value most significant 8 bits
35–37 Established timing bitmap. Supported bitmap for very common timing modes.
35 Bit 7 720×400 @ 70 Hz
Bit 6 720×400 @ 88 Hz
Bit 5 640×480 @ 60 Hz
Bit 4 640×480 @ 67 Hz
Bit 3 640×480 @ 72 Hz
Bit 2 640×480 @ 75 Hz
Bit 1 800×600 @ 56 Hz
Bit 0 800×600 @ 60 Hz
36 Bit 7 800×600 @ 72 Hz
Bit 6 800×600 @ 75 Hz
Bit 5 832×624 @ 75 Hz
Bit 4 1024×768 @ 87 Hz, interlaced (1024×768i)
Bit 3 1024×768 @ 60 Hz
Bit 2 1024×768 @ 72 Hz
Bit 1 1024×768 @ 75 Hz
Bit 0 1280×1024 @ 75 Hz
37 Bit 7 1152x870 @ 75 Hz (Apple Macintosh II)
Bits 6–0 Other manufacturer-specific display modes
38–53 Standard timing information. Up to 8 2-byte fields describing standard display modes.
Unused fields are filled with 01 01
Byte 0 X resolution, divided by 8, less 31 (256–2288 pixels, value 00 is reserved and should not be used)
Byte 1 bits 7–6 X:Y pixel ratio: 00=16:10; 01=4:3; 10=5:4; 11=16:9.
(Versions prior to 1.3 defined 00 as 1:1.)
Byte 1 bits 5–0 Vertical frequency, less 60 (60–123 Hz)
54–71 Descriptor 1 Descriptor blocks. Detailed timing descriptors, in decreasing preference order. After all detailed timing descriptors, additional descriptors are permitted:
  • Monitor range limits (required)
  • ASCII text (monitor name (required), monitor serial number or unstructured text)
  • 6 Additional standard timing information blocks
  • Colour point data
72–89 Descriptor 2
90–107 Descriptor 3
108–125 Descriptor 4
126 Number of extensions to follow. 0 if no extensions.
127 Checksum. Sum of all 128 bytes should equal 0 (mod 256).
EDID Detailed Timing Descriptor
Bytes Description
0–1 Pixel clock in 10 kHz units. (0.01–655.35 MHz, little-endian)
2 Horizontal active pixels 8 lsbits (0–4095)
3 Horizontal blanking pixels 8 lsbits (0–4095) End of active to start of next active.
4 Bits 7–4 Horizontal active pixels 4 msbits
Bits 3–0 Horizontal blanking pixels 4 msbits
5 Vertical active lines 8 lsbits (0–4095)
6 Vertical blanking lines 8 lsbits (0–4095)
7 Bits 7–4 Vertical active lines 4 msbits
Bits 3–0 Vertical blanking lines 4 msbits
8 Horizontal sync offset pixels 8 lsbits (0–1023) From blanking start
9 Horizontal sync pulse width pixels 8 lsbits (0–1023)
10 Bits 7–4 Vertical sync offset lines 4 lsbits (0–63)
Bits 3–0 Vertical sync pulse width lines 4 lsbits (0–63)
11 Bits 7–6 Horizontal sync offset pixels 2 msbits
Bits 5–4 Horizontal sync pulse width pixels 2 msbits
Bits 3–2 Vertical sync offset lines 2 msbits
Bits 1–0 Vertical sync pulse width lines 2 msbits
12 Horizontal display size, mm, 8 lsbits (0–4095 mm, 161 in)
13 Vertical display size, mm, 8 lsbits (0–4095 mm, 161 in)
14 Bits 7–4 Horizontal display size, mm, 4 msbits
Bits 3–0 Vertical display size, mm, 4 msbits
15 Horizontal border pixels (each side; total is twice this)
16 Vertical border lines (each side; total is twice this)
17 Features bitmap
Bit 7 Interlaced
Bits 6–5 Stereo mode: 00=No stereo; other values depend on bit 0:
Bit 0=0: 01=Field sequential, sync=1 during right; 10=similar, sync=1 during left; 11=4-way interleaved stereo
Bit 0=1 2-way interleaved stereo: 01=Right image on even lines; 10=Left image on even lines; 11=side-by-side
Bits 4–3 Sync type: 00=Analog composite; 01=Bipolar analog composite; 10=Digital composite (on HSync); 11=Digital separate
Bit 2 If digital separate: Vertical sync polarity (1=positive)
Other types: VSync serrated (HSync during VSync)
Bit 1 If analog sync: Sync on all 3 RGB lines (else green only)
Digital: HSync polarity (1=positive)
Bit 0 2-way line-interleaved stereo, if bits 4–3 are not 00.

When used for another descriptor, the pixel clock and some other bytes are set to 0:

EDID Other Monitor Descriptors
Bytes Description
0–1 Zero, indicates not a detailed timing descriptor
2 Zero
3 Descriptor type. FAFF currently defined. 000F reserved for vendors.
4 Zero
5–17 Defined by descriptor type. If text, code page 437 text, terminated (if less than 13 bytes) with LF and padded with SP.

Currently defined descriptor types are:

  • 0xFF: Monitor serial number (text)
  • 0xFE: Unspecified text (text)
  • 0xFD: Monitor range limits. 6- or 13-byte binary descriptor.
  • 0xFC: Monitor name (text)
  • 0xFB: Additional white point data. 2× 5-byte descriptors, padded with 0A 20 20.
  • 0xFA: Additional standard timing identifiers. 6× 2-byte descriptors, padded with 0A.
EDID Monitor Range Limits Descriptor
Bytes Description
0–4 Standard header, byte 3 = 0xFD.
5 Minimum vertical field rate (1–255 Hz)
6 Maximum vertical field rate (1–255 Hz)
7 Minimum horizontal line rate (1–255 kHz)
8 Maximum horizontal line rate (1–255 kHz)
9 Maximum pixel clock rate, rounded up to 10 MHz multiple (10–2550 MHz)
10 Extended timing information type:
00: No information, padded with 0A 20 20 20 20 20 20.
02: Secondary GTF supported, parameters as follows.
11 Reserved, must be 0.
12 Start frequency for secondary curve, divided by 2 kHz (0–510 kHz)
13 GTF C value, multiplied by 2 (0–127.5)
14–15 GTF M value (0–65535, little-endian)
16 GTF K value (0–255)
17 GTF J value, multiplied by 2 (0–127.5)
EDID 1.3 additional white point descriptor
Bytes Description
0–4 Standard header, byte 3 = 0xFB.
5 White point index number (1–255) Usually 1; 0 indicates descriptor not used.
6 White point CIE xy coordinates least-significant bits (like EDID byte 26)
Bits 7–4 Unused, must be 0.
Bits 3–2 White point x value least-significant 2 bits
Bits 1–0 White point y value least-significant 2 bits
7 White point x value most significant 8 bits (like EDID byte 27)
8 White point y value most significant 8 bits (like EDID byte 28)
9 datavalue = (gamma*100)-100 (1.0–3.54, like EDID byte 23)
10–14 Second descriptor, like above. Index number usually 2.
15–17 Unused, padded with 0A 20 20.

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