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Epson Research and Development
Vancouver Design Center
15.3 180° SwivelView™
180° SwivelView™ is accomplished by fetching the display buffer image in the reverse
address direction, starting at the bottom-right corner of the image. Unlike 90°
SwivelView™, the 180° SwivelView™ image is not rotated in the display buffer. The
image is simply displayed 180° clockwise rotated. Furthermore, a virtual window is not
required and all color depths (4/8/15/16 bpp) are supported.
15.3.1 Register Programming
Reverse Display Buffer Fetching Address Direction
Set SwivelView™ Enable bit 1 to 1. During screen refresh, the direction of the address for
display buffer fetching is reversed. This setting does not affect CPU to display buffer access
in any way. SwivelView™ Enable bit 0 should be set to 0.
Display Start Address
The Display Start Address must be programmed to be at the bottom-right corner of the
image, since the display is now refreshed in the reverse direction. The LCD Display Start
Address register (REG[042h], REG[043h], REG[044h]) must be set accordingly.
LCD Display Start Address (words)
= (MA_Offset × H) − (MA_Offset − W) − 1
for 15/16 bpp mode
= (MA_Offset × H) − (MA_Offset − W/2) − 1 for 8 bpp mode
= (MA_Offset × H) − (MA_Offset − W/4) − 1 for 4 bpp mode
where H is the height of the panel in number of lines, W is the width of the panel in number
of pixels, and MA_Offset is the LCD Memory Address Offset.
Horizontal Panning
Horizontal panning works in the same way as when SwivelView™ is not enabled, except
that the effect of the LCD Pixel Panning register is reversed:
• Increment/decrement LCD Display Start Address register pans the display window to
the right/left.
• Increment/decrement LCD Pixel Panning register pans the display window to the
left/right.
Vertical Panning
Vertical panning works in the same way as when SwivelView™ is not enabled:
• Increase/decrease LCD Display Start Address register by one memory address offset
scrolls the display window down/up by 1 line.
S1D13506
X25B-A-001-10
Hardware Functional Specification
Issue Date: 01/02/06
EPSON [ EPSON COMPANY ]
