LPS:Low power state
SoT:Start of Transmission
SP:Short Packet
LgP:Long Packet
EoT:End of Transmission
The packet includes two types which are Long packet and Short packet. The first byte
of the packet, the Data Identifier (DI), includes information specifying the type of the
packet. Command Mode systems send commands and an associated set of parameters, with the number of parameters depending on the command type.
Short packets are four bytes in length including the ECC. Short packet is used for
most Command Mode commands and associated parameters. Where Short packets
format include an 8-bit Data ID followed by two command or data and an 8-bit ECC.
Figure 4.16 shows the structure of the Short packet.
Long packets specify the payload length using a two-byte Word Count field and then
the payload maybe from 0 to 65,535 bytes in length. Long packets permit
transmission of large blocks of pixel or other data. Figure 4.17 shows the structure of
the Long packet. Long Packet Header composed of three elements: an 8-bit Data
Identifier, a 16-bit Word Count, and 8-bit ECC. An application-specific Data Payload
has Word Count * bytes following the Packet Header. The Packet Footer has one
element, a 16-bit checksum. Long packets can be from 6 to 65,541 bytes in length.
Where 65,541 bytes = 4 bytes PH + (216-1)bytes Payload + 2 bytes PF
DI (Data ID): Contain Virtual Channel Identifier and Data Type.
WC (Word Count): The receiver use WC to determine the packet end.
ECC (Error Correction Code): The Error Correction Code allows single-bit errors to
be corrected and 2-bit errors to be detected in the Packet Header.
PF (Packet Footer): Mean 16-bit Checksum.
Short packet write Command / Parameters
Long packet write Command / Parameters / Pixel Datas