Scrolling Up And Down - Epson S1D13503 Technical Manual

Epson Research and Development
Vancouver Design Center

5.5.3 Scrolling Up and Down

To scroll up, increase the value in the Screen 1 Display Start Address Register by the number of bytes in one virtual scan
line. To scroll down, decrease the value in the Screen 1 Display Start Address Register by the number of bytes in one virtual
scan line.
A virtual scan line is in reference to a virtual display, in which an image larger than the physical size of the LCD is stored.
The number of bytes in a virtual scan line is the number of bytes required to store one horizontal line of pixels in the virtual
image.
Example 16: Scroll down one line for a 16 gray shade 640 x 200 virtual image using a 320 x 240 single
1. Calculate the number of bytes in a virtual scan line.
2. Add the number of words in a virtual scan line to the Screen 1 Display Start Address Register.
In this example the Screen 1 Display Start Address points to the beginning of the image.
3. Program the Screen 1 Display Start Address.
AUX[06h] = A0h
AUX[07h] = 00h
4. This step is for dual panels only.
Add the number of words in a virtual scan line to the Screen 2 Display Start Address Register.
In this example the Screen 2 Display Start Address has previously been initialized as described in Section 5.4.3.1,
"Displaying a Single Image on a Dual Panel" on page 50.
5. This step is for dual panels only.
Program the Screen 2 Display Start Address.
AUX[08h] = least significant byte of "Screen 2 Display Start Address"
AUX[09h] = most significant byte of "Screen 2 Display Start Address"
Programming Notes and Examples
Issue Date: 01/01/30
Downloaded from Elcodis.com electronic components distributor
panel LCD. The Memory Interface is set to 16 bits to support 128k of display memory.
Also describe how to scroll in a dual panel LCD.
number of horizontal pixels in virtual image
--------------------------------------------------------------------------------------------------------- -
number of pixels per word
Screen 1 Display Start Address
Screen 2 Display Start Address
640 pixels per scan line
= ------------------------------------------------------- -
2 pixels per byte
= Screen 1 Display Start Address
320
= 0000h + -------- -
2
= 00A0h
= Screen 2 Display Start Address
= 320 bytes per scan line
number of bytes in a virtual scan line
+ ---------------------------------------------------------------------------------------- -
2 bytes per word
number of bytes in a virtual scan line
+ ---------------------------------------------------------------------------------------- -
2 bytes per word
Page 53
S1D13503
X18A-G-002-06