hd66717 Renesas Electronics Corporation., hd66717 Datasheet - Page 13

• Manufacturer Part Number: hd66717
• Description: Low-power Dot-matrix Liquid Crystal Display Controller/driver -
• Manufacturer: Renesas Electronics Corporation.

HD66717
Table 2
RS
0
1
1
Display Data RAM (DDRAM)
Display data RAM (DDRAM) stores display data represented in 8-bit character codes. Its capacity is 60
8 bits, or 60 characters, which is equivalent to an area of 12 characters
lines (LCD drive duty ratio) from 1 to 4 can be selected by software. Here, assignment of DDRAM
addresses is the same for all display modes (Table 3). The line to be displayed at the top of the display
(display-start line) can also be selected by register settings. See Table 4.
Table 3
Display
Line
1st
2nd
3rd
4th
5th
Note: Char. indicates character position.
464
0
R/W
0
1
0
1
Register Selection
DDRAM Addresses and Display Positions
20
30
40
1st
Char.
00
10
Operation
IR write as an internal operation (display clear, etc.)
Read busy flag (DB7) read and address counter (DB0 to DB6) (4/8-bit bus interface)
DR write as an internal operation (DR to DDRAM, CGRAM, SEGRAM, or annunciator)
DR read as an internal operation (DDRAM, CGRAM, or SEGRAM to DR)
(4/8-bit bus interface)
2nd
Char.
01
11
21
31
41
Figure 1 Address Counter and DDRAM Address
3rd
Char.
02
12
22
32
42
Address
counter
(AC)
4th
Char.
03
23
33
43
13
AC 6 AC5 AC4 AC3 AC2 AC1
MSB
Example : DDRAM address 4A
1
5th
Char.
04
14
24
34
44
0
0
6th
Char.
05
15
25
35
45
1
0
7th
Char.
06
16
26
36
46
1
LSB
AC0
0
8th
Char.
07
17
27
37
47
5 lines. Any number of display
9th
Char.
08
18
28
38
48
10th
Char.
09
19
29
39
49
11th
Char.
0A
1A
2A
3A
4A
12th
Char.
0B
1B
2B
3B
4B