Epson Research and Development
Page 49
Vancouver Design Center
Programming Notes and Examples S1D13706
Issue Date: 01/02/23 X31B-G-003-03
160
÷
(32
÷
4) = 20
Sub-window horizontal coordinates and horizontal width are valid.
3. Determine the main window display start address.
The main window is typically placed at the start of display memory which is at display
address 0.
main window display start address register = desired byte address
÷
4
= 0
Program the Main Window Display Start Address registers. REG[74h] is set to 00h,
REG[75h] is set to 00h, and REG[76h] is set to 00h.
4. Determine the main window line address offset.
number of dwords per line = image width
÷
(32
÷
bpp)
= 320
÷
(32
÷
4)
= 40
= 28h
Program the Main Window Line Address Offset registers. REG[78h] is set to 28h, and
REG[79h] is set to 00h.
5. Determine the sub-window display start address.
The main window image must take up 320 x 240 pixels
÷
2 pixels per byte= 9600h
bytes. If the main window starts at address 0h, the sub-window can start at 9600h.
sub-window display start address = desired byte address
÷
4
= 9600h
÷
4
= 2580h.
Program the Sub-window Display Start Address register. REG[7Ch] is set to 80h,
REG[7Dh] is set to 25h, and REG[7Eh] is set to 00h.
6. Determine the sub-window line address offset.
number of dwords per line = image width
÷
(32
÷
bpp)
= 160
÷
(32
÷
4)
= 20
= 14h
Program the Sub-window Line Address Offset register. REG[80h] is set to 14h, and
REG[81h] is set to 00h.
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