HD66750 Datasheet, PDF (42/96 Pages) Hitachi Semiconductor – 128 x 128-dot Graphics LCD Controller/Driver with Four-grayscale Functions

HD66750/1
Graphics Operation Function
The HD66750/1 can greatly reduce the load of the microcomputer graphics software processing through the
16-bit bus architecture and graphics-bit operation function. This function supports the following:
1. A write data mask function that selectively rewrites some of the bits in the 16-bit write data.
2. A bit rotation function that shifts and writes the data sent from the microcomputer in a bit unit.
3. A logical operation function that writes the data sent from the microcomputer and the original RAM
data by a logical operation.
Since the display data in the graphics RAM (CGRAM) can be quickly rewritten, the load of the
microcomputer processing can be reduced in the large display screen when a font pattern, such as kanji
characters, is developed for any position (BiTBLT processing).
The graphics bit operation can be controlled by combining the entry mode register, the bit set value of the
RAM-write-data mask register, and the read/write from the microcomputer.
Table 17 Graphics Operation
Operation Mode
Write mode 1
Bit Setting
I/D AM
0/1 00
Write mode 2
0/1 01
Write mode 3
0/1 10
Read/write mode 1 0/1 00
Read/write mode 2 0/1 01
Read/write mode 3 0/1 10
LG
00
00
00
01 10 11
01 10 11
01 10 11
Operation and Usage
Horizontal data replacement, horizontal-border
drawing
Vertical data replacement, font development, vertical-
border drawing
Vertical data replacement with two-word width, kanji-
font development
Horizontal data replacement with logical operation,
horizontal-border drawing
Vertical data replacement with logical operation,
vertical-border drawing
Horizontal data replacement with two-word-width
logical operation
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