Epson technical manual Alternate SwivelView Mode, Start Address 480 Image refreshed by S1D13705

Epson Research and Development	Page 79
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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 80K byte integrated frame buffer. For example, the panel size is 480x320 and the display mode is 4 bit-per-pixel. The minimum virtual image size for Default SwivelView Mode would be 480x512 which requires 122,880 bytes. Alternate SwivelView Mode requires a panel size of only 480x320 which needs only 76,800 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. This makes the power consumption in Alternate SwivelView Mode higher than in Default SwivelView Mode while increasing performance.

The following figure shows how the programmer sees a 480x320 image and how the image is being displayed. The application image is written to the S1D13705 in the following sense: A–B–C–D. The display is refreshed by the S1D13705 in the following sense: B-D- A-C.

physical memory start address

480

A B

SwivelView window

C D

320

image seen by programmer = image in display buffer

display		B	SwivelView window	D	320
	A			C
start
address
			480
		image refreshed by S1D13705

Figure 12-2: Relationship Between The Screen Image and the Image Refreshed by S1D13705 in Alternate Mode

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