Epson Research and Development
Page 19
Vancouver Design Center
Programming Notes and Examples
S1D13505
Issue Date: 01/02/05
X23A-G-003-07
3.1.6 Memory Organization for Sixteen Bit-Per-Pixel (65536 Colors/16 Gray Shades)
Figure 3-6: Pixel Storage for 16 Bpp (65536 Colors/16 Gray Shades) in Two Bytes of Display Buffer
In 16 bit-per-pixel mode the S1D13505 is capable of generating 65536 colors. The 65536
color pixel is divided into three parts: five bits for red, six bits for green, and five bits for
blue. In this mode the Look-Up Table is bypassed and output goes directly into the Frame
Rate Modulator.
The full color range is only available on TFT/D-TFD or CRT displays. Passive LCD
displays are limited to using the four most significant bits from each of the red, green and
blue portions of each color. The result is 4096 (2
4
* 2
4
* 2
4
) possible colors.
When monochrome mode is selected, the green component of the LUT is used to determine
the gray shade intensity. The green indices, with only four bits, can resolve 16 gray shades.
In this situation one might as well use four bit-per-pixel mode and conserve display buffer.
Bit 15
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
Red Bit 4
Red Bit 3
Red Bit 2
Red Bit 1
Red Bit 0
Green Bit 5
Green Bit 4
Green Bit 3
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Green Bit 2
Green Bit 1
Green Bit 0
Blue Bit 4
Blue Bit 3
Blue Bit 2
Blue Bit 1
Blue Bit 0