Epson S1D13708 Benutzerhandbuch
Epson Research and Development
Page 179
Vancouver Design Center
Hardware Functional Specification
S1D13708
Issue Date: 02/03/07
X39A-A-001-02
12 SwivelView™
12.1 Concept
Most computer displays are refreshed in landscape orientation – from left to right and top
to bottom. Computer images are stored in the same manner. SwivelView™ is designed to
rotate the displayed image on an LCD by 90
to bottom. Computer images are stored in the same manner. SwivelView™ is designed to
rotate the displayed image on an LCD by 90
°
, 180
°
, or 270
°
in an counter-clockwise
direction
.
The rotation is done in hardware and is transparent to the user for all display
buffer reads and writes. By processing the rotation in hardware, SwivelView™ offers a
performance advantage over software rotation of the displayed image.
performance advantage over software rotation of the displayed image.
The image is not actually rotated in the display buffer since there is no address translation
during CPU read/write. The image is rotated during display refresh.
during CPU read/write. The image is rotated during display refresh.
12.2 90° SwivelView™
90
°
SwivelView™ requires the Memory Clock (MCLK) to be at least 1.25 times the
frequency of the Pixel Clock (PCLK), i.e. MCLK
≥
1.25PCLK.
The following figure shows how the programmer sees a 320x480 portrait image and how
the image is being displayed. The application image is written to the S1D13708 in the
following sense: A–B–C–D. The display is refreshed by the S1D13708 in the following
sense: B-D-A-C.
the image is being displayed. The application image is written to the S1D13708 in the
following sense: A–B–C–D. The display is refreshed by the S1D13708 in the following
sense: B-D-A-C.
Figure 12-1 Relationship Between The Screen Image and the Image Refreshed in 90
°
SwivelView.
image seen by programmer
= image in display buffer
= image in display buffer
480
SwivelView
window
480
320
A
B
C
D
D
C
B
A
32
0
S
w
ivelView
w
ind
ow
display start address
image refreshed by S1D13708
(panel origin)
physical memory
start address