HD66750 Datasheet, PDF (29/96 Pages) Hitachi Semiconductor – 128 x 128-dot Graphics LCD Controller/Driver with Four-grayscale Functions

HD66750/1
Table 12 CT Bits and Variable Resistor Value of Contrast Adjuster
CT Set Value
CT5
CT4
CT3
CT2
CT1
CT0
Variable Resistor (VR)
0
0
0
0
0
0
3.20 x R
0
0
0
0
0
1
3.15 x R
0
0
0
0
1
0
3.10 x R
0
0
0
0
1
1
3.05 x R
0
0
0
1
0
0
3.00 x R
Â¥
Â¥
Â¥
Â¥
0
1
1
1
1
1
1.65 x R
1
0
0
0
0
0
1.60 x R
1
0
0
0
0
1
1.55 x R
1
0
0
0
1
0
1.50 x R
Â¥
Â¥
Â¥
Â¥
1
1
1
1
0
1
0.15 x R
1
1
1
1
1
0
0.10 x R
1
1
1
1
1
1
0.05 x R
Entry Mode
Rotation
The write data sent from the microcomputer is modified in the HD66750/1 and written to the CGRAM. The
display data in the CGRAM can be quickly rewritten to reduce the load of the microcomputer software
processing. For details, see the Graphics Operation Function section.
I/D: When I/D = 1, the address counter (AC) is automatically incremented by 1 after the data is written to
the CGRAM. When I/D = 0, the AC is automatically decremented by 1 after the data is written to the
CGRAM.
AM1Ð0: Set the automatic update method of the AC after the data is written to the CGRAM. When AM1Ð0
= 00, the data is continuously written in parallel. When AM1Ð0 = 01, the data is continuously written
vertically. When AM1Ð0 = 10, the data is continuously written vertically with two-word width (32-bit
length).
LG1Ð0: Write again the data read from the CGRAM and the data written from the microcomputer to the
CGRAM by a logical operation. When LG1Ð0 = 00, replace (no logical operation) is done. ORed when
LG1Ð0 = 01, ANDed when LG1Ð0 = 10, and EORed when LG1Ð0 = 11.
RT2Ð0: Write the data sent from the microcomputer to the CGRAM by rotating in a bit unit. RT3Ð0 specify
rotation. For example, when RT2Ð0 = 001, the data is rotated in the upper side by two bits. When RT2Ð0 =
111, the data is rotated in the upper side by 14 bits. The upper bit overflown in the most significant bit
(MSB) side is rotated in the least significant bit (LSB) side.
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