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LCD Controller Operation
8.2.2.3
Mapping the Display Data
The LCD controller supports 1 or 2 bits per pixel graphics mode. In the 1-bit mode, each bit in the display
memory corresponds to a pixel in the LCD panel. The corresponding pixel on the screen is either fully on
or fully off. In 2-bit mode, each pixel is represented by two bits of display memory. To map the data to the
LCD panel, program the appropriate bit in the corresponding address of the display memory. Figure 8-4
illustrates how the system memory data in both modes are mapped.
7
(0,0)
Display
Mapping
(X-8,Y-1)
7
(0,0)
(X-4,Y-1)
Display
Mapping
8.2.2.4
Generating Grayscale Tones
In 2-bits-per-pixel mode, circuitry inside the LCD controller generates intermediate grayscale tones on the
LCD panel by adjusting the density of ones and zeroes that appear over the frames. The LCD controller
can generate 16 simultaneous grayscale levels out of a palette consisting of 16 shades. The two levels
between black and white can be selected using the information in Table 8-1 on page 8-7. Use the LGPMR
registers to program the grayscale level.
8-6
(0,0)
(1,0)
(2,0)
(0,Y-1)
(1,Y-1) (2,Y-1)
1-bit-per-pixel mode
6
5
(1,0)
(2,0)
(X-7,Y-1)
(X-6,Y-1)
(X-5,Y-1)
2-bits-per-pixel mode
6
5
(1,0)
(X-3,Y-1)
Figure 8-4. Mapping Memory Data on the Screen
MC68VZ328 User's Manual
LCD Drivers
(X-1,0)
(X-1,Y-1)
4
3
(3,0)
(4,0)
(5,0)
(X-4,Y-1)
(X-3,Y-1)
4
3
(2,0)
(X-2,Y-1)
2
1
0
(6,0)
(7,0)
(X-2,Y-1)
(X-1,Y-1)
2
1
0
(3,0)
(X-1,Y-1)
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