Renesas SH7781 - Manual (Page 1046)

20. Graphics Data Translation Accelerator (GDTA)
Rev.1.00 Jan. 10, 2008 Page 1016 of 1658
REJ09B0261-0100
Table 20.8 shows ARGB8888 conversion sequence shown in figure 20.4.
No. in the table corresponds to the number used in figure 20.4. (1) and (2) correspond to the
numbers in figure 20.3.
Table 20.8 ARGB8888 Conversion Sequence
No. Operation Description
(1) Input data
reading
YUV-separated input data stored in DDR2-SDRAM is read into the GDTA.
The input data includes padding data with the specified input Y (UV)
padding size, but the GDTA excludes this padding data when reading the
data. However, if the input frame width is not on a 32-byte boundary,
padding data of the amount for 32-byte boundary adjustment is read into the
GDTA. Transfer of data from the DDR2-SDRAM to the GDTA is in 32 byte
units, so that the input data size should be an integral multiple of 32 bytes
for one line (frame width + input padding). If there are deviations in the
specified padding sizes for Y and U/V, operation is not guaranteed.
(2) Rearrangement YUV data is rearranged according to the format indicated in the display
image of figure 20.3.
(When converting from YUV 4:2:0 to YUV 4:2:2, because the data quantity
for UV is 1/2 that for Y, the UV data in even lines is used for the UV data in
odd lines. For example, the UV data in line 0 is also used in line 1.)
(3) Color
information
reading
Data converted in (2) is used as the address of the color conversion table
stored in buffer RAM 0 (CLPLPR setting address + converted data), and
color information is read from buffer RAM 0.
(Converted data: Data converted in (2) is shifted two bits to the left and
added to be the RAM 0 address.)
(Color information is read from the buffer RAM 0 address calculated by
adding the Y value read from DDR2-SDRAM to the buffer RAM 0 palette
pointer value (the address set in CLPLPR). (Same for U and V))