Preliminary
CAMERA INTERFACE
S3C2451X RISC MICROPROCESSOR
23-4
Preliminary product information describe products that are in development,
for which full characterization data and associated errata are not yet available.
Specifications and information herein are subject to change without notice.
There are two timing reference signals in ITU-R BT 656 format, one at the beginning of each video data block
(start of active video, SAV) and one at the end of each video data block(end of active video, EAV) as shown in
Figure 23-3 and below table.
Table 23-2. Video timing reference codes of ITU-656 format
Data bit number
First word
Second word
Third word
Fourth word
9 (MSB)
1
0
0
1
8
1
0
0
F
7
1
0
0
V
6
1
0
0
H
5
1
0
0
P3
4
1
0
0
P2
3
1
0
0
P1
2
1
0
0
P0
1
(Note) 1 0 0 0
0
1 0 0 0
NOTE:
For compatibility with existing 8-bit interfaces, the values of bits D1 and D0 are not defined.
F = 0 (during field 1), 1 (during field 2)
V = 0 (elsewhere), 1 (during field blanking)
H = 0 (in SAV : Start of Active Video), 1 (in EAV : End of Active Video)
P0, P1, P2, P3 = protection bit
Camera interface logic can catch the video sync bits like H(SAV,EAV) and V(Frame Sync) after reserved data as
“FF-00-00”.
VSYNC
HREF
t1
t2
t3
t1
t4
Figure 23-5 Sync signal timing diagram
Table 23-3. Sync signal timing requirement
Minimum
Maximum
t1
12 cycles of Pixel clock
-
t2
12 cycles of Pixel clock
-
t3
2 cycles of Pixel clock
-
t4
12 cycles of Pixel clock
-
Note! (t4 + t1) must be long enough to finish DMA transactions if preview is enabled or output data format of codec is RGB.
Because, DMA transaction for preview and codec RGB are delayed by 4 or 8 horizontal lines.