Epson S1D13705 - Manual (Page 116)

Page 22 Epson Research and Development
Vancouver Design Center
S1D13705 Programming Notes and Examples
X27A-G-002-03 Issue Date: 02/01/22
4.2.2 Gray Shade Modes
Gray shade modes are monochrome display modes. Monochrome display modes use the
Look-Up Table in a very similar fashion to the color modes. This most significant
difference is that the monochrome display modes use only the intensity of the green
element of the Look-Up Table to form the gray level.
One side effect of using only green for intensity selection is that in gray shade modes there
are only sixteen possible intensities. 8 bit-per-pixel is not supported for gray shade modes.
1 bpp gray shade
When the S1D13705 is configured for 1 bpp gray shade mode, the LUT is limited to
selecting colors from the first two green entries. The two LUT entries can be set to any of
sixteen possible intensities. Typically they would be set to 0h (black) and Fh (white).
Each byte in the display buffer contains eight adjacent pixels. If a bit has a value of “0” then
the color in the green LUT 0 index is displayed. A bit value of “1” results in the color in
green LUT 1 index being displayed.
The following table shows the recommended values 1 bpp gray shade display mode.
2 bpp gray shade
When the S1D13705 is configured for 2 bpp gray shade, the displayed colors are selected
from the first four green entries in the Look-Up Table. The remaining entries of the LUT
are unused. Each of the four entries can be set to any of the sixteen possible colors.
Each byte in the display buffer contains four adjacent pixels. If a bit combination has a
value of “00” then the intensity in the green LUT index 0 is displayed. A bit value of “01”
results in the intensity represented by the green in LUT index 1 being displayed. Likewise
the bit combination of “10” displays from the third LUT entry and “11” displays a from the
fourth LUT entry.
Table 4-5: Recommended LUT Values for 1 Bpp Gray Shade
Address Red Green Blue
00 00 00 00
01 00 F0 00
02 00 00 00
... 00 00 00
FF 00 00 00
unused entries