6. FUNCTIONAL DESCRIPTION
S1D15722D01B000 Technical Manual (Rev.1.1)
EPSON
17
6.2.2 Gray Scale Display
When 4-gray scale is displayed with the set display mode command, the display is expressed by controlling
FRM (frame gray scale) based on the gray scale data written to the display data RAM.
Density of gray level (gray scale 2, gray scale 1) of four gray scales is specified with the set gray scale pattern
command. The density of gray scale can be selected from 14 levels.
6.2.3 Page Address Circuit/Column Address Circuit
Use the set page address command and set column address command to specify display data RAM address to
be accessed as shown in Fig.6.5 and Fig.6.6.
The address increment direction can be selected between the column direction and page direction using the
select display data input direction command. In both directions, an increment by +1 takes place following read
or write operation.
When the address increment direction is column, the column address increments by +1 each time read or
write operation takes place. After the column address has made an access to DFH, the page address
increments by +1 and the column address moves to 0H.
When the address increment direction is page, the page address increments with the column address fixed.
After the page address has made an access to Page45, the column address increments by +1 and the page
address moves to Page0.
In both address increment directions, moves to the page address Page0 and the column address 0H after an
access to the column address DFH of the page address Page 45 is made.
As shown in Table 6.4, the correspondence between the column address of the display data RAM and
segment output can be reversed with the direction of setting column address command. Therefore, IC
arrangement comes to be less restricted when the LCD module is assembled.
Table 6.4
Correspondence between RAM
column address and SEG output
Direction of setting column address
Command register value
SEG0
→
SEG223
D0 = “0”
Column address: normal rotation
0(H)
→
DF(H)
D0 = “1”
Column address: reversal
DF(H)
←
0(H)
6.2.4 Line Address Circuit
For the line address, specify the line address corresponding to the COM output when the display data RAM is
displayed as shown in Fig.6.5 and Fig.6.6. Normally, specify the top line on display (in the state of common
output .. for normal rotation, COM0 output, for inverted, COM183 output) using the set display start line
command. The display area corresponds to the lines specified in the incremental direction from the specified
display start line address to the line address, using the number of display lines set command.
The display start line address is set every four lines of display. Dynamically changing the line address using
the set display start line command enables screen scrolling and page turning.
