
Page 52
Epson Research and Development
Vancouver Design Center
S1D13706
Programming Notes and Examples
X31B-G-003-03
Issue Date: 01/02/23
2. Confirm the sub-window coordinates are valid.
The horizontal coordinates and horizontal width must be a multiple of 32
÷
bpp.
60
÷
(32 ³ 4) = 7.5 (invalid)
120
÷
(32
÷
4) = 15
The sub-window horizontal start coordinate is invalid. Therefore, a valid coordinate
close to 60 must be chosen. For example, 8
×
(32
÷
4) = 64. Consequently the new
sub-window coordinates are (64, 80).
3. Determine the main window display start address.
The main window is typically placed at the start of display memory, which is at dis-
play address 0.
main window display start address register
= ((desired byte a (panel height
×
bpp
÷
8))
÷
4) - 1
= ((0 + (240
×
4
÷
8)
÷
4) - 1
= 29
= 1Dh
Program the Main Window Display Start Address registers. REG[74h] is set to 1Dh,
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)
= 240
÷
(32
÷
4)
= 30
= 1Eh
Program the Main Window Line Address Offset register. REG[78h] is set to 1Eh, 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 register
= ((desired byte a (sub-window width
×
bpp
÷
8))
÷
4) - 1
= ((9600h + (120
×
4
÷
8))
÷
4) - 1
= 9614
= 258Eh
Program the Sub-window Display Start Address register. REG[7Ch] is set to 8Eh,
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)