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1、Ver 1 Rev 0 Draft 2 CONFIDENTIAL NEC MITSUBISHI ELECTRIC VISUAL SYSTEMS Page 1 of 1 1C4Bxxxx 0 x S N DDC CI Command VCP Feature reply op code RC Result Code 00h NoError 01h Unsupported VCP Code CP VCP op code from Feature request message TP VCP type code 00h Set parameter 01h Momentary MH Maximum va
2、lue High byte ML Maximum value Low byte SH Present value High byte SL Present value Low byte n Nack No ack The checksum is still computed by using the 0 x50 virtual host address If Monitor reply Unsupported VCP Code message maximum value and present value are replied as follows MH ML FFh FFh SH SLl
3、00h 00h Interval 50m sec Refer to 4 1 Interval Condition PC Monitor Ver 1 Rev 0 Draft 2 CONFIDENTIAL NEC MITSUBISHI ELECTRIC VISUAL SYSTEMS Page 10 of 10 2 3 2 VESA standard Command 2 Set VCP Feature Set VCP Feature The Set VCP Feature instructs the monitor to change the parameter specified by the m
4、inor op code If the host attempts to select a value that exceeds the permissible adjustment range the monitor selects the largest permissible value S 6E a 51 a 84 a 03 a CP a SH a SL a CHK a P Receive 03H as Set VCP Feature COMMAND CP VCP op code SH High byte SL Low byte Interval 50m sec Refer to 4
5、1 Interval Condition PC Monitor Ver 1 Rev 0 Draft 2 CONFIDENTIAL NEC MITSUBISHI ELECTRIC VISUAL SYSTEMS Page 11 of 11 2 3 3 VESA standard Command 3 Save Current Settings Save Current Settings This command instructs the monitor to save all programmable values to nonvolatile Memory User memory area S
6、6E a 51 a 81 a 0C a CHK a P Receive 0CH as Save current settings op code Interval 200m sec Refer to 4 1 Interval Condition PC Monitor Ver 1 Rev 0 Draft 2 CONFIDENTIAL NEC MITSUBISHI ELECTRIC VISUAL SYSTEMS Page 12 of 12 2 3 4 VESA standard Command 4 Capabilities Request Capabilities Request A Capabi
7、lities Request message shall be issued by the computer to a device to instruct the addressed device to reply with a Capabilities Reply S 6E a 51 a 83 a F3 a OFS H a OFS L a CHK a P Receive F3H as Capabilities Request Command OFS H Offset value high byte 1 OFS L Offset value Low byte Interval 40m sec
8、 Refer to 4 1 Interval Condition S 6F a 6E a LN a E3 a OFS H a OFS L a Data 0 a Data 1 a Data 2 a Data n a CHK n P E3 Capabilities reply op code LN Length Byte length 80H Data Capability strings data ASCII code Support data Ver 1 prot type cmds and vcp Example Prot Monitor type crt Model LCD15XX Nee
9、d actual Model name Cmds 01 02 03 vcp 10 12 14 16 18 1A 20 22 24 26 28 30 32 vcp type mccs ver asset eep and mpu ver No need to support e edid sel now Refer to VESA DDC CI Implementation Guide PC Monitor Ver 1 Rev 0 Draft 2 CONFIDENTIAL NEC MITSUBISHI ELECTRIC VISUAL SYSTEMS Page 13 of 13 vcp VCP da
10、ta is an ASCII string of monitor control panel functions All op codes must be represented by two ASCII hexadecimal characters Spaces between op codes are optional The supported enumeration value of the non continuous VCPs which have multiple supports should be described by following way The VCPs whi
11、ch are required to show the capability of enumerate value are shown in the Enum value in VCP of attached VCP table Ex VCP 10 12 14 01 02 04 05 08 Above strings means Contrast Brightness and Select color preset sRGB Native 5000K 6500K 9300K are supported If VCP Page is supported Ex vcp 10 12 14 01 05
12、 06 08 16 18 1A 50 92 vcp p02 00 11 12 18 Space is not necessary beside with or but necessary with each VCP codes type The Monitor type information is defined by following strings Type LCD LCD monitor mccs ver The supported MCCS version can be defined by following strings The monitor which uses the
13、protocol in this document must support the version 1 1 or later Ex mccs ver 1 1 asset eep The models that support commands Asset read 2 send again the offset from the most recently transmitted Capabilities Request indicating the computer did not receive a response and wants a retransmit 3 send next
14、the offset from the most recently received Capabilities Reply plus the number of bytes in the message fragment new offset old offset fragment length fragment length message length 3 With these restrictions the computer can make three requests start over send current and send next See Capabilities Re
15、ply message for further details 2 1 10 4 7 Capabilities Reply A Capabilities Reply shall be used to reply to a Capabilities Request message with a fragment of data starting at offset Ver 1 Rev 0 Draft 2 CONFIDENTIAL NEC MITSUBISHI ELECTRIC VISUAL SYSTEMS Page 15 of 15 The protocol is designed to be
16、simple for the device to implement The device is free to choose the most convenient fragment size from one message to the next The only state information the device should need to maintain is the current offset and length of the most recently transmitted fragment On receiving a Capabilities Request message the device shall examine the offset field 1 If equal to zero the device shall set the current offset to zero and send the fragment from offset zero 0 2 If equal to the current offset the devic
