
Epson Research and Development
Page 55
Vancouver Design Center
Programming Notes and Examples
S1D13706
Issue Date: 01/02/23
X31B-G-003-03
2. Confirm the sub-window coordinates are valid.
The horizontal coordinates and horizontal width must be a multiple of 32
÷
bpp.
80
÷
(32
÷
4) = 10
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 a (panel width
×
panel height
×
bpp
÷
8))
÷
4) - 1
= ((0 + (320
×
240
×
4
÷
8))
÷
4) - 1
= 9599
= 257Fh.
Program the Main Window Display Start Address registers. REG[74h] is set to 7Fh,
REG[75h] is set to 25h, 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, then the sub-window can start at
9600h.
sub-window display start address
= ((desired byte a (sub-window width
×
sub-window height
×
bpp
÷
8))
÷
4) -
1 = ((9600h + (160
×
120
×
4
÷
8))
÷
4) - 1
= 11999
= 2EDFh
Program the Sub-window Display Start Address registers. REG[7Ch] is set to DFh,
REG[7Dh] is set to 2Eh, and REG[7Eh] is set to 00h.