Renesas SH7781 - Manual (Page 981)

19. Display Unit (DU)
Rev.1.00 Jan. 10, 2008 Page 951 of 1658
REJ09B0261-0100
19.4.13 Wraparound Display
In addition to display scrolling, wrap-around display, which can be used in spherical scrolling, is
possible for each plane. When enabling wrap-around display, the PnWAE bit in PnMR is set. As a
result of changing the plane n display start position X, Y (the plane n start position X set in
PnSPXR and the plane n start position Y set in PnSPYR) in order to scroll the display, even when
plane n overflows the wrap-around area, the wrap-around area is seen as a spherical surface in
wrap-around display, as in figure 19.10, and the part overflowing is complemented and displayed.
The method used to specify the wrap-around area is described below.
1. The leading address of the memory used for plane n is specified in PnDSA0R and PnDSA1R.
2. With the beginning of the specified memory as origin, the upper-left coordinates of the wrap-
around area are specified in PnWASPR. The X-direction width of the wrap-around area is the
memory width set in PnMWR.
3. The Y-direction width of the wrap-around area is set in PnWAMWR.
Plane n display area start address
Plane n wrap-around start position
Wrap-around
memory width Y
Plane n display start position
Wrap-around display
Memory width
Plane n display start position
1
2
4 3
1
3 4
2
Figure 19.10 Schematic Diagram of Wraparound Display
Note: When wrap-around display is disabled (when the PnWAE bit in PnMR is 0), the part
overflowing the wrap-around area becomes the color specified by BPOR, and
superposition processing using this color is performed.