TC5747 Datasheet, PDF (29/44 Pages) List of Unclassifed Manufacturers – Single Chip CMOS Imager with Integrated Image Signal Processor and JPEG Codec

TC5747 Preliminary Data Sheet
Single Chip CMOS Imager
4.2.7 Data Markers
Extra optional data markers are inserted at the beginning and end of each image line. The user may select
between TransChip-specific markers, and markers that conform to the ITU 656 standard.
4.2.7.1 TransChip Markers
A “ Timing signal” or Marker is defined in the ITU 656 standard as a sequence of four bytes, the first three
bytes holding reserved values of FF 00 00, and the fourth byte composed of a collection of bits whose
function is defined in the standard. The TransChip markers utilize the format of the markers as defined in
the standard, but redefines two bits in the last marker byte.
There are four types of markers:
Start of First Line marker – This marker precedes the data of the first line in a frame.
Start of Line Marker - This marker precedes the data of each line in a frame, except for the first line.
When Bayer output mode is selected, bit #5 of the marker content differentiates between a “ red” line
and a “ blue” line (0 and 1 respectively).
End of Last Line Marker - This marker immediately follows the data of the last line in a frame.
End of Line Marker - This marker immediately follows the data of each line in a frame, except for the
last line.
All markers are 4 bytes long. The first 3 bytes of all markers are identical, and annotate the marker header.
The marker content is “ FF 00 00 xy” , where xy is different for each marker type.
Marker
SOFL
Marker Header
0xFF 0x00 0x00
Marker content
DOUT[9:2] / DYUV[7:0]
0xC7
SOLR (YCrCb or “red” line)
SOLB (“blue” line)
EOLL
0xFF
0xFF
0xFF
0x00
0x00
0x00
0x00
0x00
0x00
0x80
0xAB
0xDA
EOL
0xFF 0x00 0x00 0x9D
Table 4: TransChip Markers
Bits [7:4] of the Marker-content byte carry the marker information:
Bit [7] – Always 1 to avoid 0x00 code
Bit [6] - Special frame markers (start-first-line/end-last-line)
Bit [5] – For Bayer – line “ color” (0 for Red, 1 for Blue)
Bit [4] – End/Start bit, 0 for Start-of-line marker, 1 for End-of-line
Bits [3:0] of the Marker-content byte provide parity check capability, allowing for one-bit errors to be
corrected, and two-bit errors to be detected, according to ITU-656-4 Standard.
TransChip ©
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