SH7727 Datasheet, PDF (848/1109 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH RISC engine Family/SH7700 Series

Section 25 LCD Controller
25.2.7 LCDC Line Address Offset Register for Display Data Fetch (LDLAOR)
LDLAOR sets the address width of the Y-coordinates increment used for LCDC to read the image
recognized by the graphics driver. This register specifies how many bytes the address from which
data is to be read should be moved when the Y coordinates (vertical direction) have been
incremented by 1. This register does not have to be equal to the horizontal width of the LCD
panel. When the memory address of a point (X, Y) in the two-dimensional image is calculated by
Ax + By+ C, this register becomes equal to B in this equation.
Bit: 15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
LAO15 LAO14 LAO13 LAO12 LAO11 LAO10 LAO9 LAO8 LAO7 LAO6 LAO5 LAO4 LAO3 LAO2 LAO1 LAO0
Initial value: ₀
0
0
0
0
0
1
0
1
0
0
0
0
0
0
0
R/W: _{R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W}
Bits 15 to 0—Line Address Offset (LDLAOR)
Notes: 1. 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. The lower two bits of the register are always read as 0. The
initial values (× resolution = 640) will continuously and accurately place the VGA (640
× 480 dots) display data without skipping an address between lines. For details, see
table 25.3, in section 25.3, Operation.
2. 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 (ROT = 1), the LDLAOR value
should be a binary exponential (in this example, 256) at least as large as the horizontal
width of the image (after rotation, it becomes 240 in a 240 × 320 panel) instead of the
horizontal width of the LCD panel (320 in a 320 × 240 panel).
Rev. 5.00 Dec 12, 2005 page 776 of 1034
REJ09B0254-0500