HD66710 Datasheet, PDF (60/73 Pages) Hitachi Semiconductor – (Dot Matrix Liquid Crystal Display Controller/Driver)

HD66710
Horizontal Dot Scroll
Dot unit shifts are performed by setting the horizontal dot scroll bit (HDS) when the extension register is
enabled (RE = 1). By combining this with character unit display shift instructions, smooth horizontal
scrolling can be performed on a 6-dot font width display as shown below.
5-dot font width (FW = 0)
No shift performed
Shift to the left by one dot
Shift to the left by two dots
Shift to the left by three dots
Shift to the left by four dots
6-dot font width (FW = 1)
No shift performed
Shift to the left by one dot
Shift to the left by two dots
Shift to the left by three dots
Shift to the left by four dots
Shift to the left by five dots
Figure 27 Shift in 5- and 6-Dot Font Width
(1) Method of smooth scroll to the left
RS R/W DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
1 0 0 0 0 1 DL N 1 * * Enable the extension register
20 0 1 0 0 1 _{* * * *}
CPU Wait
30 0 1 0 1 0 _{* * * *}
CPU Wait
40 0 1 0 1 1 * * * *
CPU Wait
50 0 1 1 0 0 * * * *
CPU Wait
60 0 1 1 0 1 _{* * * *}
CPU Wait
70 0 1 0 0 0 _{* * * *}
80 0 0 0 0 1 1 0 * *
CPU Wait
Shift the whole display to the left by one dot
Shift the whole display to the left by two dots
Shift the whole display to the left by three dots
Shift the whole display to the left by four dots
Shift the whole display to the left by five dots^*1
Perform no shift
Shift the whole display to the left by one character^*2
Notes: 1. When the font width is five (FW = 0), this step is skipped.
2. The extended register enable bit (RE) is cleared.
Figure 28 Smooth Scroll to the Left
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