EM65568 ELAN Microelectronics Corp, EM65568 Datasheet - Page 43

• Manufacturer Part Number: EM65568
• Description: 130 Com/ 128 Seg 4096 Color Stn Lcd Driver
• Manufacturer: ELAN Microelectronics Corp

7.12 Gradation LSB Control
In 256 color mode (C256=1), the EM65568 provides segment driver output for 8-gradation display using 3-bits and that for
4-gradation display using 2-bits.
The segment driver output for the 4-gradation display uses 2-bits written to the corresponding RAM area and 1-bit
supplemented by the gradation LSB circuit, and then selects 4-gradation form 8-gradation.
In 256 color mode (C256=1), the segment driver output for the 4-gradation display result in a gradation level of 0 regardless of
the gradation LSB, when 2-bits of data on the display RAM are “00”. When 2-bits of data on the display RAM is “11”,a
gradation level of 7/7 is selected regardless of the bit information of the gradation LSB. The other gradation levels are selected
depending on 2-bits of data on the display RAM and the gradation LSB bits.
One bit of data is supplemented by setting the gradation LSB register (GLSB).
The Gradation LSB control bit applied to all 4-gradation segment drivers.
Gradation LSB = “0”: Selects 0 as the LSB information on the RAM for 4-gradation segment drivers.
Gradation LSB = “1”: Selects 1 as the LSB information on the RAM for 4-gradation segment drivers.
7.13 Gradation Palette
The EM65568 has two gradation display modes, the gradation fixed display mode and the gradation variable display mode.
Select either of the two modes using the gradation display mode register.
Caution: Different gradation levels can’t be set the same palette.
PWM = “0”: Selects the variable display mode using 16 gradation selected from 32 gradation. (C256=0)
PWM = “1”: Selects the fixed display mode using specific 16 gradation. (C256=0)
To select the best gradation level suited to the LCD panel, use the gradation palette register among the 32-level gradation
palettes in the gradation variable display mode. The segment driver output is set up by the selected 16-levels of gradation
palettes.
The gradation palette register provides three registers for the SEGAi (0-127) group, SEGBi (0-127) group, and SEGCi (0-127)
group of segment driver outputs [palettes Aj, Bj, and Cj (j = 0-15)]. Each register consists of a 5-bit register, selecting
16-gradations from the pattern for 32-gradations.
* This specification is subject to be changed without notice.
Selects the variable display mode using 8 gradation selected from 32 gradation. (C256=1)
Selects the fixed display mode using specific 8 gradation. (C256=1)
130 COM/ 128 SEG 4096 Color STN LCD Driver
43
2005/3/8 (V1.2)
EM65568