S1D13503 Epson Electronics America, Inc., S1D13503 Datasheet - Page 137

• Manufacturer Part Number: S1D13503
• Description: S1d13503 Graphics Lcd Controller
• Manufacturer: Epson Electronics America, Inc.

Epson Research and Development
Vancouver Design Center
5.1.2 Description
Programming Notes and Examples
Issue Date: 01/01/30
The S1D13503 can be programmed to wrap memory offsets in such a way that the physical display behaves as a viewport
into a much larger “virtual” memory space. This viewport can be panned and/or scrolled to display this larger memory
space.
Referring to the figure below, a virtual image of 640x480 can be viewed by navigating the 320x240 viewport around the
image by panning and scrolling.
To create a virtual display, the Address Pitch Adjustment Register must be programmed to indicate the horizontal size of
the larger, “virtual” image stored in display memory. The Address Pitch Adjustment Register tells the S1D13503 how
many bytes or words of display memory are part of the nonvisible region of display memory (see Example 12).
Example 12: Program the Address Pitch Adjustment Register to support a 16 color 640 x 480 virtual
1.
2.
3.
4.
5.
6.
Initialize the S1D13503 registers for a 320x240 panel.
Determine whether the Address Pitch Adjustment Register refers to bytes or words.
Since the Memory Interface is set to 16 bits, the Address Pitch Adjustment Register refers to words.
Determine the number of pixels per unit referred to by the Address Pitch Adjustment Register.
The Address Pitch Adjustment Register refers to units of words, so find the number of pixels per word.
Calculate the number of pixels on a horizontal scan line not visible.
Consequently on a screen update the S1D13503 will show the first 320 of 640 pixels, and then ignore the remaining
320 pixels in order to reach the next scan line.
Program the Address Pitch Adjustment Register
Therefore AUX[0Dh] = 50h
To view the rest of the image refer to Section 5.5, “Panning and Scrolling” on page 52, keeping in mind that the hor-
izontal width is 640 pixels, not 320.
display on a 320 x 240 LCD panel; the Memory Interface is 16 bits.
virtual display width in pixels
16 colors => 4 bits per pixel
4 bits per pixel => 2 pixels per byte
pixels per word
number of hidden horizontal pixels
----------------------------------------------------------------------------------- -
Figure 13: Moving A Viewport Inside A Virtual Display
pixels per word
=
320x240
Viewport
pixels per byte
–
panel width in pixels
“Virtual” Display
=
640x480
2
320
-------- -
4
=
2 2
=
80 words
=
640 320
=
4 pixels per word
–
=
50h words
=
320 hidden pixels
X18A-G-002-06
S1D13503
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