S1D13505 Epson Electronics America, Inc., S1D13505 Datasheet - Page 190

• Manufacturer Part Number: S1D13505
• Description: LCD Controller
• Manufacturer: Epson Electronics America, Inc.

Page 36
S1D13505
X23A-G-003-07
REG[13h] Screen 2 Display Start Address Register 0
REG[14h] Screen 2 Display Start Address Register 1
REG[15h] Screen 2 Display Start Address Register 2
Start Addr
Start Addr
Bit 15
Bit 7
n/a
Start Addr
Start Addr
Bit 14
Bit 6
n/a
These two registers form a value known as the line compare. When the line compare value
is equal to or greater than the physical number of lines being displayed there is no visible
effect on the display. When the line compare value is less than the number of physically
displayed lines, display operation works like this:
1. From the end of vertical non-display to the number of lines indicated by line compare
2. After line compare lines have been displayed the display will begin showing data
These three registers form the twenty bit offset to the first word in the display buffer that
will be shown in the screen 2 portion of the display.
Screen 1 memory is always displayed first at the top of the screen followed by screen 2
memory. The start address for the screen 2 image may be lower in memory than that of
screen 1 (i.e. screen 2 could be coming from offset 0 in the display buffer while screen 1
was coming from an offset located several thousand bytes into the display buffer). While
not particularly useful, it is possible to set screen 1 and screen 2 to the same address.
the display data will be from the memory pointed to by the Screen 1 Display Start Ad-
dress.
from Screen 2 Display Start Address memory.
Start Addr
Start Addr
Bit 13
Bit 5
Figure 5-7: Screen 2 Display Start Address
n/a
Start Addr
Start Addr
Bit 12
Bit 4
n/a
Start Addr
Start Addr
Start Addr
Bit 11
Bit 19
Bit 3
Start Addr
Start Addr
Start Addr
Bit 10
Bit 18
Bit 2
Epson Research and Development
Start Addr
Start Addr
Start Addr
Programming Notes and Examples
Bit 17
Bit 1
Bit 9
Vancouver Design Center
Issue Date: 01/02/05
Start Addr
Start Addr
Start Addr
Bit 16
Bit 0
Bit 8