Epson S1D13705 technical manual How to Set Up Alternate SwivelView Mode

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	Vancouver Design Center

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

REG[10h], REG[0Dh], REG[0Ch] =	AddressOfPixelB
= (AddressOfPixelA + ByteOffset)
	 320pixels ⋅		4bpp	– 1
= AddressOfPixelA + 		--------------------------------------------8bpb	

= AddressOfPixelA + 9Fh

Where bpp is bits-per-pixel and bpb is bits-per-byte.

•The Line Byte Count Register for SwivelView Mode must be set to the image width in bytes, i.e.

REG[1Ch] =	-----------------------------------------320	= 320-------- = 160 = A0h
	(8bpb) ⎟ (4bpp)	2

Where bpb is bits-per-byte and bpp is bits-per-pixel.

•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

S1D13705	Hardware Functional Specification
X27A-A-001-10	Issue Date: 02/02/01