HD66727 Datasheet, PDF (20/97 Pages) Hitachi Semiconductor – Low-Power Dot-Matrix Liquid Crystal Display Controller/Driver with Key Scan Function

HD66727
Character Generator RAM (CGRAM)
Character generator RAM (CGRAM) of 32 × 6 bits allows the user to redefine the character patterns. In the
case of 6 × 8-dot characters, up to four characters may be redefined.
Write the character codes at addresses “00”H to “03”H into DDRAM to display the character patterns
stored in CGRAM (Table 8).
Table 8
Example of Relationships between Character Code (DDRAM) and Character Pattern
(CGRAM Data)
Character code (DDRAM data)
D7 D6 D5 D4 D3 D2 D1 D0
0000* * 00
CGRAM address
A4 A3 A2 A1 A0
MSB
CGRAM data LSB
O7 O6 O5 O4 O3 O2 O1 O0
00
000 * *
0 10001
0 0 1 (Don't care) 0 1 0 0 0 1
010
0 10001
011
0 01010
100
0 00100
101
0 00100
110
0 00100
111
0 00000
Character
pattern
(1)
0000* * 11
11
000 * *
0 10001
0 0 1 (Don't care) 0 1 0 0 0 1
010
0 10001
011
0 01010
100
0 00100
101
0 00100
110
0 00100
111
0 00000
Character
pattern
(4)
Notes: 1. The lower 2 bits of the character code correspond to the upper two bits of the CGRAM address
(2 bits: 4 types).
2. CGRAM address bits 0 to 2 designate the character pattern raster-row position. The 8th raster-
row is the cursor position and its display is formed by a logical OR with the cursor.
3. In the 5-dot font width, the higher three bits of the CGRAM data are invalid; use the lower five
bits (O4 to O0). In the 6-dot font width, the higher two bits are invalid.
4. When the upper four bits (bits 7 to 4) of the character code are 0, CGRAM is selected.
Bits 3 and 2 of the character code are invalid (*). Therefore, for example, the character codes
00H and 08H correspond to the same CGRAM address.
5. A set bit in the CGRAM data corresponds to display selection, and 0 to non-selection.
Segment RAM (SEGRAM)
Segment RAM (SEGRAM) is used to enable control of segments such as icons and marks by the user
program. Segments and characters are driven by a multiplexing drive method.
20