Epson S1D13506 Technical Manual page 148

Page 142
LCD Miscellaneous Register
REG[041h]
n/a n/a
bit 1
bit 0
S1D13506
X25B-A-001-12
n/a
Dithering Disable
When this bit = 1, dithering on the passive LCD panel for 15/16 bpp mode is disabled
allowing a maximum of 4096 colors (2
When this bit = 0, dithering on the passive LCD panel for 15/16 bpp mode is enabled
allowing a maximum of 64K colors (2
Note
This bit has no effect in 4/8 bpp modes where dithering is not supported.
All passive STN color panels are controlled using 3 bits for each pixel (RGB) for a total of
8 possible colors. LCD controllers use a combination of Frame Rate Modulation (FRM)
and dithering to achieve more than 8 colors per pixel. FRM can achieve 16 shades of color
for each RGB component resulting in a total of 4096 possible colors (16x16x16). Dithering
uses a 4 pixel square formation and applies a set of 4 hard-coded patterns for each of the 16
shades of color. This expands the original 16 shades of color from the FRM logic to 64
shades per RGB component which results in 256K colors per pixel (64x64x64).
For the S1D13506, 16 bpp is arranged as 5-6-5 RGB. In this mode, when dithering is
enabled, the LUT is bypassed and the original 16-bit data is used as a pointer into the 64
shades per color in the following manner.
(5-6-5 RGB) 32 possible Red, 64 possible Green, 32 possible Blue
This combination of FRM and dithering results in 256K colors/pixel, however, the 16 bpp
limitation of the S1D13506 limits this to 64K colors/pixel.
Dual Panel Buffer Disable
This bit is used to disable the Dual Panel Buffer.
When this bit = 1, the Dual Panel Buffer is disabled.
When this bit = 0, the Dual Panel Buffer is enabled.
When a single panel is selected, the Dual Panel Buffer is automatically disabled and this
bit has no effect.
The Dual Panel Buffer is needed to fully support dual panels. Disabling the Dual Panel
Buffer will improve performance, reduce power consumption, and allow higher resolu-
tion/ color display modes than would otherwise be possible; however, disabling the Dual
Panel Buffer will reduce image contrast and overall display quality. This mode is not nor-
mally used except in special circumstances such as simultaneous display on a CRT/TV
and dual panel LCD. For details on Frame Rate Calculation, see Section 17.
n/a n/a
12
) or 16 gray shades.
16
) or 64 gray shades.
Epson Research and Development
Vancouver Design Center
Dithering
n/a
Disable Buffer Disable
Hardware Functional Specification
Issue Date: 02/03/26
RW
Dual Panel