HD66766R Datasheet, PDF (51/97 Pages) Hitachi Semiconductor – 132 x 176-dot Graphics LCD Controller/Driver for 65K Colors

HD66766R
Rev. 1.0-1 / September 2002
Graphic Operation Function
The HD66766R can greatly reduce the load of the microcomputer graphics software processing through
the 16-bit bus architecture and internal 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 conditional write function that compares the write data and compare-bit data and writes the data sent
from the microcomputer only when the conditions match. Even if the display size is large, the display
data in the graphics RAM ( GRAM ) can be quickly rewritten. The graphics bit operation can be
controlled by combining the entry mode resister. The bit set value of the RAM-write –data mask resister,
and the write from the microcomputer.
Operation Mode
Bit Setting
I/D AM LG2-0
Write mode 1 0 /1
0
000
Write mode 2 0 /1
1
000
Write mode 3 ^{0 /1}
0
110,111
Write mode 4 0 /1
1
110,111
Operation and Usage
Horizontal data replacement, horizontal - border drawing
Vertical data replacement, vertical - border drawing
Conditional horizontal data replacement, horisontal - border drawing
Conditional vertical data replacement, vertical - border drawing
Table 33 Graphics operation
+1/-1 _{+ 256}
Address
counter
( AC )
Microcomputer
16
Write data latch
16
Logical / compare operation (LG2 - 0:)
000: replacement bit.
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matched write,
unmatched write
Write bit mask
Graphic RAM ( GRAM )
Logical operation bit
( LG2 - 0 )
Compare bit ( CP7 - 0 )
Write mask register
( WM15 - 0 )
Figure 37 Graphics Operation flow
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