TC5747 Datasheet, PDF (30/44 Pages) List of Unclassifed Manufacturers – Single Chip CMOS Imager with Integrated Image Signal Processor and JPEG Codec

TC5747 Data Sheet
Single Chip CMOS Imager
4.2.7.2 ITU 656 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.
Bits [7:4] of the Marker-content byte carry the marker information:
Bit [7] – Always 1 to avoid 0x00 code
Bit [6] – F – field 0 or field 1
Bit [5] – V - blank or active video line indication (0 for active, 1 for blank)
Bit [4] – H - 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.
When adhering to the bit-definition of the ITU-656 standard, there is a need to distinguish between
consecutive frames, either by inserting markers on at least one blank line between frames, or by toggling the
field bit on every frame start.
The PVI supports the following options.
Marker
SAV - active
SAV - blank
EAV - active
EAV - blank
SAV - active
SAV - blank
EAV - active
EAV - blank
Field
0
0
0
0
1
1
1
1
Marker Header
0xFF 0x00 0x00
0xFF 0x00 0x00
0xFF 0x00 0x00
0xFF 0x00 0x00
0xFF 0x00 0x00
0xFF 0x00 0x00
0xFF 0x00 0x00
0xFF 0x00 0x00
Marker content
DOUT[9:2] / DYUV[7:0]
Table 5: ITU 656 Markers
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