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Filename:
SAA7115_Datasheet.fm
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Last edited by H. Lambers
Philips Semiconductors
CS-PD Hamburg
CVIP2
Datasheet
SAA7115
Date:
10/23/01
Version:
0.67
8.5.1
S
CALER OUTPUT FORMATTER
(
SUBADDRESSES
93H
AND
C3H)
The output formatter organizes the packing into the output FIFO. The following formats are available: Y-C
B
-C
R
4 : 2 : 2,
Y-C
B
-C
R
4 : 1 : 1, Y-C
B
-C
R
4 : 2 : 0, Y-C
B
-C
R
4 : 1 : 0, Yonly (e.g. for raw samples). The formatting is controlled by
FSI[2:0] 93H[2:0], FOI[1:0] 93H[4:3] and FYSK[93H[5]].
The data formats are defined on Dwords, or multiples, and are similar to the video formats as recommended for PCI
multimedia applications, but planar formats are not supported.
FSI[2:0] defines the horizontal packing of the data, FOI[1:0] defines how many Y only lines are expected, before a Y/C
line will be formatted. If FYSK is set to logic 0 preceding Y only lines will be skipped, and the output will always start with
a Y/C line.
Additionally the output formatter limits the amplitude range of the video data (controlled by ILLV[85H[5]]); see Table 23.
Table 21
Byte stream for different output formats
Table 22
Explanation to Table 21
Table 23
Limiting range on I-port
8.5.2
V
IDEO
FIFO (
SUBADDRESS
86H)
The video FIFO at the scaler output contains 32 Dwords. That corresponds to 64 pixels in 16-bit Y-C
B
-C
R
4 : 2 : 2 format.
But as the entire scaler can act as a pipeline buffer, the actual available buffer capacity for the image port is much higher,
and can exceed beyond a video line.
The video FIFO provides 4 internal flags, reporting to what extent the FIFO is actually filled.
These are:
The FIFO Almost Empty (FAE) flag
The FIFO Combined Flag (FCF) or FIFO filled, which is set at almost full level and reset, with hysteresis, only after the
level crosses below the almost empty mark
The FIFO Almost Full (FAF) flag
The FIFO Overflow (FOVL) flag.
OUTPUT FORMAT
BYTE SEQUENCE FOR 8-BIT OUTPUT MODES
Y-CB-CR 4 : 2 : 2
Y-CB-CR 4 : 1 : 1
Yonly
CB0
CB0
Y0
Y0
Y0
Y1
CR0
CR0
Y2
Y1
Y1
Y3
CB2
CB4
Y4
Y2
Y2
Y5
CR2
CR4
Y6
Y3
Y3
Y7
CB4
Y4
Y8
Y4
Y5
Y9
CR4
Y6
Y10
Y5
Y7
Y11
CB6
CB8
Y12
Y6
Y8
Y13
NAME
EXPLANATION
CBn
Yn
CRn
CB (B
Y) colour difference component, pixel number n = 0, 2, 4 to 718
Y (luminance) component, pixel number n = 0, 1, 2, 3 to 719
CR (R
Y) colour difference component, pixel number n = 0, 2, 4 to 718
LIMIT STEP
ILLV[85H[5]]
VALID RANGE
SUPPRESSED CODES (HEXADECIMAL VALUE)
DECIMAL VALUE
HEXADECIMAL VALUE
LOWER RANGE
UPPER RANGE
0
1
1 to 254
8 to 247
01 to FE
08 to F7
00
FF
00 to 07
F8 to FF