sed1355 ETC-unknow, sed1355 Datasheet - Page 170

• Manufacturer Part Number: sed1355
• Description: Sed1355 Embedded Ramdac Lcd/crt Controller
• Manufacturer: ETC-unknow

Page 14
3.1.5 Memory Organization for Fifteen Bit-Per-Pixel (32768 Colors/16 Gray Shades)
3.1.6 Memory Organization for Sixteen Bit-Per-Pixel (65536 Colors/16 Gray Shades)
SED1355
X23A-G-003-05
Bit 15
Red Bit 4
Bit 7
Green Bit 2
Green Bit 2
Reserved
Bit 15
Bit 7
Bit 14
Red Bit 3
Bit 6
Green Bit 1
Figure 3-5: Pixel Storage for 15 Bpp (32768 Colors/16 Gray Shades) in Two Bytes of Display Buffer
Figure 3-6: Pixel Storage for 16 Bpp (65536 Colors/16 Gray Shades) in Two Bytes of Display Buffer
Green Bit 1
Red Bit 4
Bit 14
Bit 6
In 15 bit-per-pixel mode the SED1355 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 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
Should monochrome mode be chosen at this color depth, the output reverts to sending the four most
significant bits of the green LUT component to the modulator for a total of 16 possible gray shades.
In this situation one might as well use four bit-per-pixel mode and conserve display buffer.
In 16 bit-per-pixel mode the SED1355 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
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 13
Red Bit 2
Bit 5
Green Bit 0
Green Bit 0
Red Bit 3
Bit 13
Bit 5
Bit 12
Red Bit 1
Bit 4
Blue Bit 4
Blue Bit 4
Red Bit 2
Bit 12
Bit 4
4
4
* 2
* 2
4
4
* 2
* 2
4
4
Bit 11
Bit 3
Red Bit 0
Blue Bit 3
) possible colors.
) possible colors.
Blue Bit 3
Red Bit 1
Bit 11
Bit 3
Bit 10
Green Bit 5
Bit 2
Blue Bit 2
Blue Bit 2
Red Bit 0
Bit 10
Bit 2
Epson Research and Development
Programming Notes and Examples
Bit 9
Green Bit 4
Bit 1
Blue Bit 1
Green Bit 4
Blue Bit 1
Bit 9
Bit 1
Vancouver Design Center
Issue Date: 99/04/27
Bit 8
Green Bit 3
Bit 0
Blue Bit 0
Green Bit 3
Blue Bit 0
Bit 8
Bit 0