Texas Instruments SPRAA56 appendix Modifications to the Base Example

Application Report

SPRAA56 – September 2004

DSP/BIOS Real-Time Analysis (RTA) and Debugging Applied to a Video Application

Brian Jeff	DSP Field Software Applications
Arnie Reynoso	Software Development Systems

ABSTRACT

DSP/BIOS and the Reference Frameworks allow developers to non-intrusively instrument real-time applications. The software provided with this application note applies real-time analysis (RTA) services to a working application—a H.263 encode/decode loopback example for the TMS320DM642 evaluation module. The software demonstrates techniques for benchmarking and controlling video software. It also introduces a service to programmatically measure CPU and TSK loading. Debugging and troubleshooting techniques for real-time applications, using Code Composer Studio, is also discussed.

		Contents
1 Important Benchmarks for Video Applications			2
2	Base Application Overview		3
	2.1	DSP/BIOS and RF5 Components Used	5
	2.2	Requirements for Viewing RTA Benchmarks	7
3 Modifications to the Base Example			7
	3.1	Splitting the Encode and Decode CELLs	8
	3.2	Adding the Control TSK and MBX Communication	8
	3.3	Querying the H.263 Encoder for Status	9
	3.4	Controlling the Frame Rate	10
4 RTA Techniques for Performance Measurement			11
	4.1	Measuring Function Execution Time with the UTL Module	11
	4.2	Measuring Task Scheduling Latencies	12
	4.3	Measuring End-to-End Latencies	12
	4.4	Measuring the Frame Rate	13
	4.5	Simulating High CPU Load Stress Conditions with Dummy NOP Loads	14
	4.6	Programmatic Measurement of Total CPU Load	14
	4.7	Memory Bus Utilization	15
	4.8	Bitrate and Frame Type	17
	4.9	Methods for Transmitting Measured Performance Data	18
	4.10 Application-Specific Control via GEL Scripts in CCStudio		19
5 Viewing Benchmarks in the Instrumented Application			19
	5.1	Requirements	19
	5.2	Running the Application	20
	5.3	Interpreting the Benchmarks	22
	5.4	Controlling the Run-Time Parameters Dynamically	25
6	References		26
Appendix A. Performance Impact			27
	A.1	Overhead of Performance Measurement Techniques	27
	A.2	RTA Effects on CPU Load	27
	A.3	Memory Footprint	28

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