Epson S1D13705 - Manual (Page 86)

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S1D13705 Hardware Functional Specification
X27A-A-001-10 Issue Date: 02/02/01
12.2.1 How to Set Up Alternate SwivelView Mode
The following describes the register settings needed to set up Alternate SwivelView Mode
for a 320x480x4 bpp image.
• Select Alternate SwivelView Mode:
REG[1Bh] bit 7 = 1 and bit 6 = 1
• The display refresh circuitry starts at pixel “B”, therefore the Screen 1 Start Address
register must be programmed with the address of pixel “B”, or
• The Line Byte Count Register for SwivelView Mode must be set to the image width in
bytes, i.e.
• Panning is achieved by changing the Screen 1 Start Address register:
• Increment the register by 1 to pan horizontally by one byte, e.g. two pixels in 4 bpp
mode
• Increment the register by the value in the Line Byte Count register to pan vertically by
one line, e.g. add A0h to pan by one line in the example above
REG[10h], REG[0Dh], REG[0Ch] AddressOfPixelB =
AddressOfPixelA ByteOffset +
( )
=
AddressOfPixelA
320pixels 4bpp
×
8bpb
--------------------------------------------  
 
1 – + =
AddressOfPixelA 9Fh + =
Where bpp is bits-per-pixel and bpb is bits-per-byte.
REG 1Ch
[ ] 320
8bpb
( )
4bpp
( ) ÷
------------------------------------------
320
2
--------- 160 A0h = = = =
Where bpb is bits-per-byte and bpp is bits-per-pixel.