
PRELIMINARY
S3C6400X RISC MICROPROCESSOR
JPEG CODEC
22-5
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.
Table 22-1. Markers at JPEG CODEC
Marker
Codes(Hex)
Description
SOI
FFD8
Start of image
SOF
0
FFC0
Baseline
DCT
SOS
FFDA
Start of scan
DQT
FFDB
Define quantization table
DHT
FFC4
Define Huffman table
DRI
FFDD
Define restart interval
RSTm
FFD0~FFD7
Restart with module 8 count “m”
EOI
FFD9
End of image
The markers in Table 1 are subject to process during decompression. The other markers except SOF1~SOFF
and JPG will be ignored.
BITSTREAM OF COMPRESSED FILE
The created JPEG Bit Stream is shown below.
SOI
DQT
DRI
SOF0
DHT
SOS
ECS
EOI
Figure 22-3. Bit stream of JPEG file Block Diagram
PROGRAMMER’S MODEL
Process start command instructs to start the encoding or decoding process of one frame, after setting various
registers. It is set by writing 0x1 on the
SW_JSTART
register. Then, the core processing will start and then
JPGSTS
will be high. Operation can’t be guaranteed when this command is issued again during processing. Do
not set like that.
Table 22-2. Registers that must be configured before start processing
Register
Description
At Encoding process At Decoding process
JPGMOD
Process mode register Essential
Essential
JPGQHNO Quantization and Huffman table number register
Essential
--