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PRELIMINARY
JPEG CODEC
S3C6400X RISC MICROPROCESSOR
22-8
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.
JPEG DECODING SEQUENCE: SOFTWARE CONTROLLED DECODING
Start
Decoding proc.
Set
JPGMOD
Set
IMG_ADDRx
Set
HUF_ADDRx
Encoding proc.
Finished
N
Y
Set
MISC
Set
SW_JSTART
N
HD_IRQ
is high ?
Y
Set
SW_JRSTART
MAIN_IRQ
is high ?
N
Read
JPGIRQ
Y
Read
JPGSTS
Decoding
more frame?
Figure 22-5. Example flow chart of software controlled decoding
Take the following steps for software controlled JPEG decoding:
1. Set the process mode to decoding process in
JPGMOD
2. Set the destination address of 1st decoded image data I
MG_ADDR0
and 2nd decoded image data
address
IMG_ADDR1
3. Set the source address of 1st JPEG file
HUFADDR0
and next JPEG file Address
HUFADDR1
4. Set the Miscellaneous register
MISC (set MODE_SEL to 0x1 or 0x2 , DMS bit to 0)
5. Set
the
SW_JSTART
to high.
6. If HD_IRQ is high and ERR_IRQ is low, read
JPGIRQ
register to clear internal pended IRQ
.
7. Set
the
SW_JRSTART
to high.
8. If MAIN_IRQ is high and ERR_IRQ is low, read frame size (in byte) from
JPGCNT
register