This directory contains a standalone demo that can be compiled, copied to the SD card, and booted and executed on the eZdsp without a PC.
C:\Program Files\Texas Instruments\ccsv4\emulation\boards\ezdsp5535_v1\boot_post_SDcard
Import the project into CCS and compile it. Then follow the instructions in this text file to create a bootable .bin file and copy that file to the SD card:
C:\Program Files\Texas Instruments\ccsv4\emulation\boards\ezdsp5535_v1\boot_post_SDcard\Creating_Bootable_Demo.txt
After copying the bootimg1.bin file to the SD card (and removing other .bin files), the device can be powered with an external USB power supply and will load and execute the code on the SD card.
One of the demos is an audio loopback that reads data from the microphone and plays it back to the headphones. This is probably a good starting point for writing filters. Read the data, do something to it, then write it out to the headphones.
Unfortunately the audio loopback demo isn't working quite right for me yet. I can hear the headphones pop as the DAC is unmuted, but I don't hear the microphone input on the headphones.
EDIT: The stand alone audio loopback demo is working now. It requires a line-level input at the stereo in jack, not a microphone-level input. (The corresponding source code file is named aic3204_loop_linein.c.) It's not clear to me yet how the sample rate is set, but anyway, the code is clearly reading data from the line in and writing data to the headphone out - which should be enough to stick a filter in-between.
EDIT 2: Looks like DSPLIB has a lot of filter-related functions. Combining the stand alone loopback demo and some functions from DSPLIB can probably go a long way towards making a software-enhanced/-defined radio. http://processors.wiki.ti.com/index.php/DSPLIB