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PRELIMINARY
S3C6400X RISC MICROPROCESSOR
MULTI-FORMAT VIDEO CODEC
21-6
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.
Hardware Acceleration
The BIT processor core embeds hardware acceleration sub-modules as followings.
-
Accelerator to support bitstream packing instruction such as
put_bits
-
Accelerator to support bitstream unpacking instructions such as
get_bits
and
show_bits
-
Look-up table and searching module for VLC and VLD operation
-
Motion vector prediction/reconstruction module
-
DMA controller to transfer bitstream from/to external SDRAM
Downloading the firmware
The BIT firmware to drive the video codec module and interface with a host processor is divided into 2 parts.
One is for boot code that is downloaded by the host processor through the APB bus. The size of the boot code is
1024-byte. Another is for codes for codec processing such as MPEG-4, H.263, H.264 and VC-1. The procedure
for downloading the firmware is executed only once at the initialization step.
Boot code
Before running codec, a host processor must download the BIT boot code to the program memory, 2048x16
synchronous single-port SRAM, through the host interface as following.
Step 1.
addr
= 0;
Step 2.
code_data = (addr << 16) + bit_code[addr]
Step 3. write
code_data
to the
CodeDownLoad
register of the host
interface embedded in the BIT processor
Step 4.
addr = addr + 1
Step 5. if (
addr
< 512) go to step 1 else go to the procedure to
download the codec firmware (refer to the 5.3.2)
The bit_code is an array of which size is 512 * 16-bit.
Note:
Above bit_code[0-511] has to be also written in a region specified in the
CodeBufAddr
register of the host
interface.