SED1374 Datasheet, PDF (115/420 Pages) Epson Company – SED1374 Embedded Memory Color LCD Controller

Epson Research and Development
Vancouver Design Center
Page 19
REG[17h] Look-Up Table Data Register
n/a
n/a
n/a
n/a
LUT Data
Bit 3
LUT Data
Bit 2
LUT Data
Bit 1
Read/Write
LUT Data
Bit 0
LUT Data
This register is where the 4-bit red/green/blue data value is written/read. With each
successive read or write the internal RGB selector is incremented. Depending on the RGB
Index setting, one to three access of this register will result in the Look-Up Table Address
incrementing.
4.2 Look-Up Table (LUT) Organization
Color and monochrome operation is slightly different. Both Look-Up Table schemes are
described here.
• The Look-Up Table treats the value of a pixel as an index into an array of colors or gray
shades. For example, a pixel value of zero would point to the first LUT entry; a pixel
value of 7 would point to the eighth LUT entry.
• The value inside each LUT entry represents the intensity of the given color or gray
shade. This intensity can range in value between 00 and 0Fh.
The following table shows how many elements from each Look-Up Table index are used
at the different color depths.
Table 4-4: Look-Up Table Configurations
Display Mode
1 Bpp Gray
2 Bpp Gray
4 Bpp Gray
4-Bit Wide Look-Up Table
Red
Green
Blue
4 banks of 2
4 banks of 4
1 bank of 16
1 Bpp Color
2 Bpp Color
4 Bpp Color
8 Bpp Color
4 banks of 2
4 banks of 4
1 bank of 16
2 banks of 8
4 banks of 2
4 banks of 4
1 bank of 16
2 banks of 8
4 banks of 2
4 banks of 4
1 bank of 16
4 banks of 4
Indicates the Look-Up Table is not used for that display mode
Programming Notes and Examples
Issue Date: 99/04/27
SED1374
X26A-G-002-02