HD66730 Datasheet, PDF (73/131 Pages) Hitachi Semiconductor – Dot-Matrix Liquid Crystal Display Controller/Driver Supporting Japanese Kanji, Korean Font Display

HD66730/HD66731
Display Control Register 1 (R3)
The display control register 1 (Figure 10) includes bits ST, DC, and DS.
ST: When ST is 1, the display control register 1 enters the standby mode. The internal operation clock is
divided into 32. Data cannot be displayed on the LCD panel, however, the consumption current can be
suppressed during the standby mode. Note that the register setting value and the data inside the RAM are
maintained.
DC: When DC is 1, the character display is turned on.
DS: When DS is 1, the segment display is turned on. Bit DS can selectively display marks.
Display Control Register 2 (R4)
NC1/0: Selects the display character in the horizontal direction. When performing a horizontal smooth
scroll, set the number of display characters larger than the actual number of liquid crystal drive characters.
When the frame frequency (cycle) is stable, the operation frequency is proportional to the display
characters. Operation frequency must be suppressed by setting the number of display character as small as
possible because the consumption current is proportional to the operation frequency. Refer to Oscillator for
details.
NL1/0: Sets the number of display lines. Set the number of display lines larger than the duty drive ratio
(DT1/0). Do not set 10 to these bits. Table 13 indicates the settings of the display lines.
Table 14 Display Control Register 2 Setting
Display Lines
NL1/0
00
01
10
11
00
1-line 6 characters
2-line 6 characters
4-line 6 characters
Display Characters: NC1/0
01
10
1-line 20 characters
1-line 40 characters
2-line 10 characters
2-line 20 characters
Setting is inhibited.
4-line 10 characters
4-line 10 characters
R/W RS DB7
DB0
0 1 0 0 0 0 0 ST DC DS
Figure 10 Display Control Register 1
R/W RS DB7
0100
DB0
0 NC1 NC0 0 NL1 NL0
Figure 11 Display Control Register 2
72