DS508UM1
99
6.17.2
PALLSW — Least Significant Word — LCD Palette Register
ADDRESS: 0x8000.0580
The least and most significant word LCD palette registers make up a 64-bit read / write register which
maps the logical pixel value to a physical grayscale level. The 64-bit register is made up of 16 x 4-bit
nibbles, each nibble defines the grayscale level associated with the appropriate pixel value. If the LCD
controller is operating in two bits-per-pixel, only the lower 4 nibbles are valid (D[0-15] in the least sig-
nificant word). Similarly, one bit-per-pixel means only the lower 2 nibbles are valid (D[0-7]) in the least
significant word.
6.17.3
PALMSW — Most Significant Word — LCD Palette Register
ADDRESS: 0x8000.0540
The pixel to grayscale level assignments and the actual physical color and pixel duty ratio for the gray-
scale values are shown in Table 54 on page 100. Note that colors 8
–
15 are the inverse of colors 7
–
0
respectively. This means that colors 7 and 8 are identical. Therefore, in reality only 15 grayscales
available, not 16. The steps in the grayscale are non-linear, but have been chosen to give a close
approximation to perceived linear grayscales. The is due to the eye being more sensitive to changes
in gray level close to 50% gray (See
PALLSW
description).
31-28
27-24
23-20
19-16
15-12
11-8
7-4
3-0
Grayscale
value for pixel
value 7
Grayscale
value for pixel
value 6
Grayscale
value for pixel
value 5
Grayscale
value for pixel
value 4
Grayscale
value for pixel
value 3
Grayscale
value for pixel
value 2
Grayscale
value for pixel
value 1
Grayscale
value for pixel
value 0
31-28
27-24
23-20
19-16
15-12
11-8
7-4
3-0
Grayscale
value for pixel
value 15
Grayscale
value for pixel
value 14
Grayscale
value for pixel
value 13
Grayscale
value for pixel
value 12
Grayscale
value for pixel
value 11
Grayscale
value for pixel
value 10
Grayscale
value for pixel
value 9
Grayscale
value for pixel
value 8
Summary of Contents for EP7312
Page 8: ...DS508UM1 9 Part I EP7312 User s Manual...
Page 58: ...DS508UM1 59 Part II Pin and Register Reference...
Page 122: ......