SH7760 Datasheet, PDF (1098/1345 Pages) Renesas Technology Corp – SuperHTM RISC engine

Note: 1. The minimum alignment unit of LDSARU and LDSARL is four bytes. Because the LCDC
handles these values as longword data, the values written to the lower two bits of each
register are always treated as 0. The lower two bits of each register are always read as 0.
For 1 or 2 bpp, set the registers so that the start of each line is aligned with the longword
boundary (32 bits). (Data at the start of each line is always valid.) Data that exceeds the
longword boundary at the end of each line (1, 2, or 3 bytes) will be discarded. For 4, 8, 15,
or 16 bpp, set the registers so that the start of each line is aligned with the longword
boundary (32 bits).
30.3.7 LCDC Display Line Address Offset Register (LDLAOR)
LDLAOR specifies the Y-coordinate increment address width used by the LCDC to read an image
recognized by the graphics driver. When the Y-coordinate is increased by 1, this register specifies
by how many bytes the address for reading data from memory should be moved, and it needs not
conform to the width of the LCD panel. This register corresponds to B when the equation Ax + By
+ C is used to calculate the memory address of a point (X, Y) in a two dimensional image.
Bit: 15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
LAO15 LAO14 LAO13 LAO12 LAO11 LAO10 LAO9
Initial value: 0
0
0
0
0
0
1
R/W: R/W R/W R/W R/W R/W R/W R/W
LAO8
0
R/W
LAO7
1
R/W
LAO6
0
R/W
LAO5
0
R/W
LAO4
0
R/W
LAO3
0
R/W
LAO2
0
R/W
LAO1
0
R/W
LAO0
0
R/W
Bit
Bit Name Initial Value R/W
15 to 10 LAO15 to All 0
R/W
LAO10
9
LAO9 1
R/W
8
LAO8 0
R/W
7
LAO7 1
R/W
6 to 0 LAO6 All 0
R/W
to
LAO0
Description
Line Address Offset
The minimum alignment unit of LDLAOR is four bytes.
Because the LCDC handles these values as longword
data, the values written to the lower two bits of the
register are always treated as 0. When reading from
the register, the lower two bits are always read as 0.
In order for VGA (640 × 480 dot) display data to be
read continuously without skipping an address
between lines, the initial value is set to (× resolution =
640). For details, see table 30.4, Display Resolutions
when Using Display Rotation, in section 30.4,
Operation.
A binary exponential at least as large as the horizontal
width of the image is recommended for the LDLAOR
value, taking into consideration the software operation
speed.
When the hardware rotation function is used, the
LDLAOR value should not correspond to the width of
the LCD panel (320 in a 320 × 240 panel), but should
be a binary exponential (in this example, 256) at least
as large as the horizontal width of the image (after
rotation, 240 in a 240 × 320 panel).
Rev. 1.0, 02/03, page 1048 of 1294