r8a77850anbg Renesas Electronics Corporation., r8a77850anbg Datasheet - Page 1057

• Manufacturer Part Number: r8a77850anbg
• Description: Renesas 32-bit Risc Microcomputer Superh? Risc Engine Family
• Manufacturer: Renesas Electronics Corporation.

(2)
The CPU performs required initialization and starts the processing. IDCT data must be prepared in
the buffer RAM 1. The procedure is shown below.
No. Operation
(7) IDCT data
(8) Estimated
(9) Estimated
reading
image data
generation
image data
writing
MC Processing Procedure
Description
IDCT data stored in buffer RAM 1 is read.
(Only blocks specified by a CBP setting of 1 are read from buffer RAM 1.)
The IDCT data should be stored in buffer RAM 1 as 16-bit signed data.
(The sign is discriminated using the uppermost bit (bit 15).)
Regardless of the CBP value, the IDCT data should be stored in successive
addresses in the order Y0 (128 bytes), Y1 (128 bytes), Y2 (128 bytes), Y3
(128 bytes), U (128 bytes), V (128 bytes).
When there is a CBP=0 block, the address space should not be packed, but
data should be stored in successive addresses in the Y0, Y1, Y2, Y3, U, V
data format.
The CBP value indicates whether a sign is required compared with the
comparison image for the six blocks (four luminance blocks and two
chrominance blocks). The above Y0, Y1, Y2, Y3, U, V are CBP values of
block positions in the following format.
CBP Blocks with YUV4:2:0
(Data for a CBP=0 block: data invalid)
9-bit saturation computation is performed for IDCT data read from RAM 1 (-
256 ≤ x ≤ 255).
(The sign is discriminated using the uppermost bit (bit 15).)
IDCT data reading is performed in parallel with the operation of (5) and (6).
Estimated image data is generated using the following formula from the half-
pixel processing data generated in (6) and the IDCT data (9-bit data after
saturation computation) read in (7).
Formula: (data of (6) + data of (7)) -> (saturation computation) (0 ≤ x ≤ 255)
Estimated image data is written to DDR2-SDRAM at the address computed in
(1) and (2).
Luminance Y
Y0
Y2
20. Graphics Data Translation Accelerator (GDTA)
Y1
Y3
Rev.1.00 Jan. 10, 2008 Page 1027 of 1658
Chrominance
U/V
REJ09B0261-0100
U
V