hd66765 Renesas Electronics Corporation., hd66765 Datasheet - Page 26

• Manufacturer Part Number: hd66765
• Description: 396-channel Segment Driver With Internal Ram For 4096-color Displays - Hitachi Semiconductor
• Manufacturer: Renesas Electronics Corporation.

Formula for the frame frequency
fosc: R-C oscillation frequency
Duty: drive duty (NL bit)
Division ratio: DIV bit
Clock cycles per raster-row: (RTN + 25) clock cycles
Vertical Scroll Control (R11h)
VL17–10: Specify the display-start raster-row at the 1st screen display for vertical smooth scrolling.
Any raster-row from the first to 176th can be selected. After the 176th raster-row is displayed, the
display restarts from the first raster-row. The display-start raster-row (VL17–10) is valid only when
VLE1 = 1. The raster-row display is fixed when VLE1 = 0. (VLE1 is the 1st-screen vertical-scroll
enable bit.)
VL27–20: Specify the display-start raster-row at the 2nd screen display. The display-start raster-row
(VL27–20) is valid only when VLE2 = 1. The raster-row display is fixed when VLE2 = 0. (VLE2 is the
2nd-screen vertical-scroll enable bit.) The vertical scroll for the 1st and 2nd screens can be independently
set.
Table 22
VL27
VL17
0
0
0
:
1
1
Note: Do not set over the 176th (AFH) raster-row.
Frame frequency =
R/W
W
RS
1
VL26
VL16
0
0
0
:
0
0
VL Bits and Display-start Raster-row
VL27
DB15
VL25
VL15
0
0
0
:
1
1
VL26
DB14
Clock cycles per raster-row division ratio 1/duty cycle
VL25
DB13
VL24
VL14
0
0
0
:
0
0
Figure 15 Vertical Scroll Control Instruction
VL24
DB12
VL23
VL13
0
0
0
:
1
1
VL23
DB11
VL22
DB10
VL22
VL12
0
0
0
:
1
1
fosc
VL21
DB9
26
VL21
VL11
0
0
1
:
1
1
VL20
DB8
VL17
DB7
VL20
VL10
0
1
0
:
0
1
VL16
DB6
Display-start Raster-row
1st raster-row
2nd raster-row
3rd raster-row
:
175th raster-row
176th raster-row
VL15
DB5
VL14
DB4
VL13
DB3
[Hz]
VL12
DB2
HD66765
VL11
DB1
VL10
DB0