Epson Research and Development
Page 17
Vancouver Design Center
3.3 Memory Organization for 8 Bpp (256 Colors/16 Gray Shades)
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Pixel 0
Bits 7-0
Figure 3-2: Pixel Storage for 8 Bpp in One Byte of Display Buffer
At a color depth of eight bpp each byte of display buffer represents one pixel on the display.
At this color depth the read-modify-write cycles of 4 bpp are eliminated making the update
of each pixel faster.
Each byte indexes into one of the 256 positions of the LUT. The S1D13506 LUT supports
four bits per primary color. This translates into 4096 possible colors when color mode is
selected. Therefore the displayed mode has 256 colors available out of a possible 4096.
When a monochrome panel 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.
Note
When a monochrome panel (REG[030h] bit 2 = 0) is selected, a four bpp color depth
also provides 16 gray shades and uses less display buffer.
3.4 Memory Organization for 15 Bpp (32768 Colors/32 Gray Shades)
Bit 15
Reserved
Bit 7
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
Red Component
Bits 4-0
Green Component
Bits 4-3
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Green Component
Bits 2-0
Blue Component
Bits 4-0
Figure 3-3: Pixel Storage for 15 Bpp in Two Bytes of Display Buffer
At a color depth of 15 bpp the S1D13506 is capable of displaying 32768 colors. The 32768
color pixel is divided into four parts: one reserved bit, five bits for red, five bits for green,
and five bits for blue. In this mode the LUT is bypassed and output goes directly into the
Frame Rate Modulator.
Programming Notes and Examples
Issue Date: 01/02/06
S1D13506
X25B-G-003-03
EPSON [ EPSON COMPANY ]
