S1D13742 Epson, S1D13742 Datasheet - Page 95

• Manufacturer Part Number: S1D13742
• Description: Mobile Graphics Engine
• Manufacturer: Epson

Epson Research and Development
Vancouver Design Center
16 SwivelView™
16.1 Concept
16.2 90° SwivelView™
16.2.1 Register Programming
Hardware Functional Specification
Issue Date: 2007/09/18
physical memory
start address
Figure 16-1: Relationship Between The Screen Image and the Image Refreshed in 90° SwivelView.
image seen by programmer
= image in display buffer
C
A
SwivelView
window
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°, 180°, or 270° in a counter-clockwise
direction. The rotation is done in hardware and is transparent to the user for all display
buffer writes. By processing the rotation in hardware, SwivelView™ offers a performance
advantage over software rotation of the displayed image.
The actual address translation is performed during the Host Write and is therefore stored in
memory as rotated. Because of where the rotation logic is, each Window written to the
S1D13742 can be independently rotated with respect to each other.
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 S1D13742 in the
following sense: A–B–C–D. The display is refreshed in the following sense: B-D-A-C.
There is no special programming requirements other than simply enabling the rotation
itself. All start addresses and Line Offset’s are automatically calculated by hardware.
320
D
B
Revision 6.01 - EPSON CONFIDENTIAL
display start address
(panel origin)
www.DataSheet.co.kr
image refreshed by the S1D13742
480
X63A-A-001-06
S1D13742
Page 95
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