Texas Instruments OMAP5912 Reference Manual page 686

System DMA
Figure 9. 2-D Transparent Color Block Diagram
Match
Constant Fill
Figure 10. 2-D Constant Color Fill Block Diagram
62 Direct Memory Access (DMA) Support
2-D graphic transparent color block diagram
Source element
Match
Color key
This feature is enabled by setting the TRANSPARENT_COPY_ENABLE bit in
the channel control 2 register, DMA_CCR2. If this bit is enabled, the DMA color
parameter registers, DMA_COLOR_L and DMA_COLOR_U, are used to
specify the color key.
If the data type, ES, is 8 or 16 bits, only the DMA_COLOR_L register is used;
if the data type is 32 bits, the DMA_COLOR_U register is also used. The
system DMA always compares all bits (8, 16, or 32 bits). If other color depths
(other than 8, 16, or 32) are used, it is the responsibility of the software to
ensure that unused upper bits are constant. See the register description for
more detailed information.
LCh Types Supporting this Feature yp pp g
This feature allows filling a region with a constant (solid color) or a pattern by
repeating the data horizontally and/or vertically in the region. The system DMA
writes to the destination a constant color/value defined in a register. There is
no read access on any system DMA source port.
2-D constant color-fill block diagram
Source element
Constant color key
No read access
on source port
Destination element
No write
2D P PD
√
Destination element
Constant color key
Write access on
destination port
No write
G D
√
SPRU755B