DISPLAYING
CUSTOMIZED CHARACTER USING CGROM IN LCD DISPLAY LM016L
In LCD display we have seen that, when we send ASCII
value it directly display.
Actually the CGROM has all ASCII value store in it.
So when we send any ASCII value it compare it with CGROM and displays it.
A user defined Character Patterns can also be
generated using mask-programmed ROM.
To Generate a Customized Character like Symbol,
smiley etc.
We use 5x8 dot matrix to generate a symbol.
Don’t Care
|
5 COLUMN
|
Hex value
|
|||||||
8
R
O
W
|
0
|
0
|
0
|
0
|
X
|
X
|
X
|
0
|
0x0E
|
0
|
0
|
0
|
X
|
X
|
X
|
X
|
X
|
0x1F
|
|
0
|
0
|
0
|
X
|
0
|
0
|
0
|
X
|
0x11
|
|
0
|
0
|
0
|
X
|
0
|
0
|
0
|
X
|
0x11
|
|
0
|
0
|
0
|
X
|
0
|
0
|
0
|
X
|
0x11
|
|
0
|
0
|
0
|
X
|
0
|
0
|
0
|
X
|
0x11
|
|
0
|
0
|
0
|
X
|
X
|
X
|
X
|
X
|
0x1F
|
|
0
|
0
|
0
|
X
|
X
|
X
|
X
|
X
|
0x1F
|
|
X= 1;
0 = 0;
Higher 3-bit are don’t care because the data send is
8bit
So we use addition 3-bits a predefined 0 and rest of
5 bit are the 5 columns and 8 row are used to defined each row and column in
the display.
X indicates that the bit is 1.
0 indicates the bit as 0.
In 5x8 matrix only the higher 3 bit are don’t care.
The symbol Created is a Battery symbol. We can
generator many type of symbol using mask-programmed ROM (CGROM location that
are unused)
The Hex value created for symbol must be place in
CGROM location 40H.
The 40H memory has 8 addressable location from 00 to 07.
And while displaying we should mention addressable location of 40H that are storing 8-byte data in each location from 0x00 to 0x07.
Each location i.e. 0x00 hold 8-byte data.
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