Epson Research and Development
Page 81
Vancouver Design Center
Hardware Functional Specification
S1D13704
Issue Date: 01/02/08
X26A-A-001-04
12.2 Alternate SwivelView Mode
Alternate SwivelView Mode may be used when the virtual image size of Default
SwivelView Mode cannot be contained in the 40kByte integrated frame buffer. For
example, the panel size is 240x160 and the display mode is 8 bit-per-pixel. The minimum
virtual image size for Default SwivelView Mode would be 240x256 which requires 60K
bytes. Alternate SwivelView Mode requires a panel size of only 240x160 which needs only
38,400 bytes.
Alternate SwivelView Mode requires the memory clock (MCLK) to be at least twice the
frequency of the pixel clock (PCLK), i.e. MCLK
≥
2 x PCLK. Because of this, the power
consumption in Alternate SwivelView Mode is higher than in Default SwivelView Mode.
The following figure shows how the programmer sees a 240x160 image and how the image
is being displayed. The application image is written to the S1D13704 in the following
sense: A–B–C–D. The display is refreshed by the S1D13704 in the following sense: B-D-
A-C.
Figure 12-2: Relationship Between The Screen Image and the Image Refreshed by S1D13704
image seen by programmer
= image in display buffer
240
SwivelView
window
240
160
A
B
C
D
D
C
B
A
16
0
start
address
S
wivelView
w
ind
ow
display
image refreshed by S1D13704
start
address
physical
memory
*