SH7785 Datasheet, PDF (1043/1692 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer

20. Graphics Data Translation Accelerator (GDTA)
20.4 GDTA Operation
20.4.1 Explanation of CL Operation
By writing 1 to the CL_EN bit in GACER, registers in the CL register unit can be accessed. After
setting, as initial values, the input frame width/height, input padding size, output padding size,
operating mode (and, in ARGB conversion mode, the palette pointer setting), data written in
succession to CLCF is received, and upon receiving four command parameters (input Y/U/V
pointers, output pointer), processing is begun. In processing, data for one input frame as defined
by the settings (width vs. height) is read, and by setting the CL_MD bit in CLCR, YUYV
conversion or ARGB conversion is performed within the module. Processing is performed in
single frame units, and one frame's worth of converted data is transmitted to the output destination.
The CL can store two commands (in register CLCF) and does not accept the command for the next
frame when two commands are already stored (command FIFO full). A judgment as to whether
processing has ended can be made by using either an interrupt or the CL_END bit in GACISR.
(1) Overview of YUYV Conversion Functions
The following shows an outline of the YUYV conversion specification.
DDR2-SDRAM
Input
Y pointer
Input
U pointer
Y0 Y1 Y2 Y3
Y4 Y5 Y6 Y7
**
**
**
**
...
**
**
**
**
Y8 Y9 ...
U0 U1 U2 U3
**
**
**
**
...
**
**
**
**
U4 U5 ...
Input
V pointer
Output
pointer
V0 V1 V2 V3
**
**
**
**
...
**
**
**
**
V4 V5 _...
Y0 U0 Y1 V0
Y2 U1 Y3 V1
Y4 U2 Y5 V2
Y6 U3 Y7 V3
**
**
**
**
...
**
**
**
**
Y8 U0 Y9 V0
Y10 U1 ...
In the example of this figure, H'8 is set in CLIWR
and H'30 is set in CLOPR.
Display image
Frame width (8 pixels in this figure)
Output padding size (= 48 bytes)
(1) Input data
reading
Y0 U0 Y1 V0 Y2 U1 Y3 V1 Y4 U2 Y5 V2 Y6 U3 Y7 V3
Y8 U0 Y9 V0 Y10 U1 Y11 V1 Y12 U2 Y13 V2 Y14 U3 Y15 V3
Converted data output order
Y16 U4 Y17 V4 Y18 U5 Y19 V5 Y20 U6 Y21 V6 Y22 U7 Y23 V7
Y24 U8 Y25 V8 Y26 U9 Y27 V9 Y28 U10 Y29 V10 Y30 U11 Y31 V11
Y32 U1 Y33 V12 Y34 U13 Y35 V13 Y36 U14 Y37 V14 Y38 U15 Y39 V15
(2) Rearrangement (with output padding)
External memory
connected to the
local bus
(3) Output data writing (including output padding data)
For output
(= 16 bytes)
Not for output
(= 32 bytes)
Depending on the specified width and padding size,
there may exist either one or neither of "padding data
for output" and "padding data not for output".
Figure 20.3 YUYV Conversion Functions
Rev.1.00 Jan. 10, 2008 Page 1013 of 1658
REJ09B0261-0100