MB86290A Datasheet, PDF (42/184 Pages) Fujitsu Component Limited. – Graphics Controller Hardware Specifications

4.2 Frame Management
4.2.1 Single Buffer
The entire or partial area of the drawing frame is assigned as a display frame.
The display field is scrolled by relocating the position of the display frame.
When the display frame crosses the border of the drawing frame, the other
side of the drawing frame is displayed, assuming that the drawing frame is
rolled over (top and left edges assumed logically connected to bottom and
right edges, respectively). To avoid the affect of drawing on display, the
drawing data can be transferred to the Graphics Memory in the blanking
time period.
4.2.2 Double Buffer
Two drawing frames are set. While one frame is displayed, drawing is done
at the other frame. Flicker-less animation can be performed by flipping these
two frames back and forth. Flipping is done in the blanking time period.
There are two flipping modes: automatically at every scan frame period, and
by user control. The double buffer is assigned independently for the Base
and Middle layers. When the screen partition mode is selected (so that both
Base and Middle layers split into separate left and right windows), the double
buffer can be assigned independently for left and right windows.
42