SED1354 Datasheet, PDF (123/472 Pages) Epson Company – Color Graphics LCD/CRT Controller

Epson Research and Development
Vancouver Design Center
Page 115
9.1 Image Buffer
The image buffer contains the formatted display data - see Section 10.1, “Display Mode Data
Format” on page 116.
The displayed image(s) may take up only a portion of the image buffer; the remaining area can be
used for multiple images - possibly for animation or general storage. See Section 10, “Display
Configuration” on page 116 for details on the relationship between the image buffer and the display.
9.2 Half Frame Buffer
In dual panel mode, with the half frame buffer enabled, the top of the display buffer is allocated to
the half-frame buffer. The size of the half frame buffer is a function of the panel resolution and
whether the panel is color or monochrome:
Half Frame Buffer Size (in bytes) = (panel width x panel length) * factor / 16
where factor = 4 for color panel
= 1 for monochrome panel
For example, for a 640x480 8 bpp color panel the half frame buffer size is 75K bytes. In a 512K byte
display buffer, the half-frame buffer resides from 6D400h to 7FFFFh. In a 2M byte display buffer,
the half-frame buffer resides from 1ED400h to 1FFFFFh.
Hardware Functional Specification
Issue Date: 99/05/18
SED1354
X19A-A-002-16