S1D13503 Epson Electronics America, Inc., S1D13503 Datasheet - Page 148

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

Page 52
5.5 Panning and Scrolling
5.5.1 Initialization
5.5.2 Panning Right and Left
S1D13503
X18A-G-002-06
7.
8.
Panning and scrolling are typically used to show an image which is too large to be shown completely on an LCD panel.
Although the image is stored entirely in display memory, only a small portion is actually visible on the LCD panel. This
visible portion is called the viewport; the user moves this viewport over different portions of the image by panning and
scrolling. Panning moves the viewport right or left. Scrolling moves the viewport up or down.
To pan and scroll over a large image, the S1D13503 registers must first be initialized and the image written to display
memory. To do so, initialize the registers as described in Section 2, “INITIALIZING THE S1D13503” on page 10, but with
the following exception: the Address Pitch Adjustment Register in the S1D13503 must be set to create a virtual display;
see Section 5.1, “Virtual Displays” on page 40 for more information.
To pan to the right, increase the value in the Screen 1 Display Start Address Register. To pan to the left, decrease the value
in the Screen 1 Display Start Address Register.
Note that the S1D13503 can pan right or left by either 1, 2, 4, 8, or 16 pixels. This is because the Screen 1 Display Start
Address Register refers to either bytes or words (see Section 4.2.1, “S5U13503B00C Evaluation Board Display Memory”
on page 36), and a byte can represent 1, 2, 4, or 8 pixels, and so a word can represent 2, 4, 8, or 16 pixels; see Table 5-1
below:
Screen 2 Display Start Address Register
Program the Screen 2 Display Start Address Register to point to the beginning of the second half of the image.
The second half of the image is placed right after the first half, as shown below:
AUX[08h] = 00h
AUX[09h] = 4Bh
Write both the first and second halves of the image to their respective locations in display memory.
Interface
Memory
16 bits
8 bits
Table 5-1: Smallest Number Of Pixels For Panning
Gray Levels
Colors/
=
=
256
256
16
16
2
4
2
4
Screen 1 Display Start Address Register
0000h
+
9600h
-------------- -
2
Pixels per Byte
=
4B00h
8
4
2
1
8
4
2
1
Smallest Number of Pixels
Epson Research and Development
+
size of first half of image in bytes
--------------------------------------------------------------------------------
for Panning
Programming Notes and Examples
16
8
4
2
1
8
4
2
2 bytes per word
Vancouver Design Center
Issue Date: 01/01/30