Allied International V2.4.0 Benutzerhandbuch
Camera interfaces
OSCAR Technical Manual V2.4.0
49
Pixel data
Pixel data are transmitted as isochronous data packets in accordance with
the 1394 interface described in IIDC V1.3. The first packet of a frame is iden-
tified by the 1 in the sync bit (sy) of the packet header.
the 1394 interface described in IIDC V1.3. The first packet of a frame is iden-
tified by the 1 in the sync bit (sy) of the packet header.
•
The video data for each pixel are output in either 8-bit or 12-bit format.
•
Each pixel has a range of 256 or 4096 shades of gray.
•
The digital value 0 is black and 255 or 4095 is white. In 16-bit mode
the data output is MSB aligned.
the data output is MSB aligned.
Field
Description
data_length
Number of bytes in the data field
tg
Tag field
shall be set to zero
channel
Isochronous channel number, as programmed in the iso_channel
field of the cam_sta_ctrl register
field of the cam_sta_ctrl register
tCode
Transaction code
shall be set to the isochronous data block packet tCode
sy
Synchronization value (sync bit)
This is one single bit. It indicates the start of a new frame.
It shall be set to 0001h on the first isochronous data block of a frame,
and shall be set to zero on all other isochronous blocks
and shall be set to zero on all other isochronous blocks
Video data payload
Shall contain the digital video information
Table 20: Description of data block packet format
0-7
8-15
16-23
24-31
data_length
tg
channel
tCode
sy
header_CRC
Video data payload
data_CRC
Table 19: Isochronous data block packet format. Source: IIDC V1.3
sync bit