Digital Signal Processing Reference
In-Depth Information
graphics simple so that the design will fit on the FPGA chip. If the video game needs a
random number generator, information on random number generation can be found in
Appendix A.
8.
Use the character font ROM and the ideas from the MIPS character output example to
add video character output to another complex design.
9.
Using Matlab or C, write a program to convert a color bitmap into a *.mif file with run-
length encoding. Design a state machine to read out the memory and generate the RGB
color signals to display the bitmap. Use a reduced resolution pixel size such as 160 by
120. Find a bitmap to display or create one with a paint program. It will work best if the
bitmap is already 160 by 120 pixels or smaller. A school mascot or your favorite cartoon
character might make an interesting choice. Limited internal memory is available in the
FPGA, so a 12-bit RLE format with nine bits for length and three bits for color can be
used with up to 7,600 locations on the UP3. Some boards have more slightly more
memory as seen in Table 2.1. This means that the bitmap can only have several thousand
color changes as the image is scanned across the display. Simple images such as cartoons
have fewer color changes. A Matlab example is on the DVD.
10.
Add color mixing or dithering with more than 8 colors to the previous problem. The 3-bit
color code in the RLE encoded memory can be used to map into a color palette. The
color palette contains the RGB patterns used for color mixing or interlacing. On boards
that support more than 8 colors directly in hardware, the color palette value can be used
directly to drive several of the higher RGB output bits. The color palette memory selects
8 different colors. The program translating the bitmap should select the 8 closest colors
for the color palette.
11.
Modify the VGA Sync core to support a higher screen resolution and demonstrate it
using one of the earlier example video designs
.
