
Page 34
Epson Research and Development
Vancouver Design Center
SED1352
Programming Notes and Examples
X16-BG-007-04
Issue Date: 98/10/08
5.4 Split Screen
This section describes how to create a split screen for both single and dual LCD panels. For single panel displays, the
Screen 1 Display Line Count Registers are used. For dual panel displays, the Screen 2 Display Start Address Registers are
used.
5.4.1 Registers
This register is used to enable the split screen display feature (single panel only) where two different images can be
displayed at the same time on one display. This register has no effect when using a dual panel configuration.
bits 7-0
Screen 1 Display Line Count Bits [7:0]
These bits are the seven LSB of a 9-bit value used to determine the number of lines displayed for screen 1.
The remaining lines will automatically display from the screen 2 display start address. The 9-bit value pro-
grammed is the number of display lines -1.
For example, if AUX[0A] = 20h for a 320x240 display system. The display will show 20h+1 = 33 lines on
the upper part of the screen according to display starting address AUX[06] and AUX[07] and 240 - 33 =
207 lines on the lower part of the screen according to display starting address AUX[08] and AUX[09].
Two different images can be displayed when using a dual panel configuration by changing the screen 2 dis-
play start address. However, by using this method screen 2 is limited to the lower half of the display.
bits 1-0
Screen 1 Display Line Count Bits [9:8]
These are the two MSB of the Screen 1 Display Line Count Register.
AUX[0A] Screen 1 Display Line Count Register (LSB)
I/O address = 1010b, Read/Write.
Screen 1
Display
Line Count
Bit 7
Screen 1
Display
Line Count
Bit 6
Screen 1
Display
Line Count
Bit 5
Screen 1
Display
Line Count
Bit 4
Screen 1
Display
Line Count
Bit 3
Screen 1
Display
Line Count
Bit 2
Screen 1
Display
Line Count
Bit 1
Screen 1
Display
Line Count
Bit 0
AUX[0B] Screen 1 Display Line Count Register (MSB)
I/O address = 1011b, Read/Write.
n/a
n/a
n/a
n/a
n/a
n/a
Screen 1
Display
Line Count
Bit 9
Screen 1
Display
Line Count
Bit 8