This is a based on Fischl.de's TI Stellaris Launchpad logic analyser (http://www.fischl.de/arm/sllogiclogger_logic_analyser_for_stellaris_launchpad).
Major changes:
Increased buffer length from 16KB to 31KB (http://www.sodnpoo.com/posts.xml/longer_buffer_for_stellaris_logic_analyser.xml)
Sampling is SysTick interrupt driven (http://www.sodnpoo.com/posts.xml/variable_sample_rate_stellaris_logic_analyser.xml)
Bufferless/continuous sampling (http://www.sodnpoo.com/posts.xml/bufferless_stellaris_logic_analyser.xml)