Texas Instruments SPRAA56 Viewing Benchmarks in the Instrumented Application, Requirements

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SPRAA56

The benchmarking routines send out selected benchmark data at a prescribed interval: every

30th frame, every I (Intracoded) frame, or only on a dropped frame. The interval can be selected by controlling the .rtaMode variable within the control structure.

Benchmark data is transmitted to the CCStudio on the host PC via RTDX (Real-Time Data eXchange), which is used behind the scenes by the DSP/BIOS RTA tools. RTDX allows Code Composer Studio to read from or write to target buffers in DSP addressable memory at run-time. For example, the UTL_logDebug2 API command use RTDX to move two variables and a message to the Message Log window available from the DSP/BIOS menu in CCStudio.

Although the channel used in this example is the standard debugging connection, data could be sent over any channel with sufficient bandwidth to an endpoint where you can view the data. For example, the benchVideoProcRta data structure could be sent over Ethernet in a networked encoder or decoder application to provide statistics to a third-party receiving application.

The current size of the debug structure is small (defined in Appendix A), so sending the structure once every 30 frames would introduce a negligible load on the system and the network, yet could still provide useful information at that rate.

4.10Application-Specific Control via GEL Scripts in CCStudio

As mentioned earlier, run-time control is provided by the h263rateControl.gel script. The menu item controls in the script allow you to manipulate the global benchVideoProcRta structure from the host PC.

menuitem "Rate Control --bitrate-framerate"; slider setFrameRate(0, 30, 1, 1, framerate)

{

controlVideoProc.frameRateChanged = 1; controlVideoProc.frameRateTarget = framerate;

}

For details on the GEL language and its functions, see the “Using the Integrated Development Environment” section of the Code Composer Studio online help.

5Viewing Benchmarks in the Instrumented Application

Now that we have described the available benchmarks, this section tells how to measure those benchmarks while running the application.

5.1Requirements

To run the application supplied with this note, you need the following components:

•DM642 EVM and Board Support Package

•CCStudio v2.21 or greater

•JTAG emulator

•Input video source – composite or S-Video

•Video display – composite or S-Video

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

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Contents References Appendix A. Performance Impact Modifications to the Base ExampleRTA Techniques for Performance Measurement Viewing Benchmarks in the Instrumented ApplicationFigures Important Benchmarks for Video ApplicationsSPRAA56 Base Application OverviewTskInput 1 LOG DSP/BIOS and RF5 Components Used3 TRC 2 STS4 UTL Requirements for Viewing RTA Benchmarks Modifications to the Base ExampleAdding the Control TSK and MBX Communication Splitting the Encode and Decode CELLsTskInput Querying the H.263 Encoder for StatusTskO utput Controlling the Frame Rate Measuring Function Execution Time with the UTL Module RTA Techniques for Performance MeasurementMeasuring End-to-End Latencies Measuring Task Scheduling LatenciesMeasuring the Frame Rate Programmatic Measurement of Total CPU Load Memory Bus Utilization External memory 720*480 = 345,600 B86,400 B 14,400 BBitrate and Frame Type Methods for Transmitting Measured Performance Data Application-Specific Control via GEL Scripts in CCStudio Viewing Benchmarks in the Instrumented ApplicationRequirements Load the h263loopbackrta.out program Running the ApplicationSPRAA56 Interpreting the Benchmarks Expected Values for the STS Objects Expected and Measured STS Benchmarks Expected and Measured Logged Benchmarks Debug ModeExpected Values Delivered to the Message Log Controlling the Run-Time Parameters DynamicallyCapture and Display Task Benchmarking ReferencesMeasured Performance of Benchmarking Techniques Appendix A. Performance ImpactOverhead of Performance Measurement Techniques RTA Effects on CPU LoadMemory Footprint Details Memory FootprintImportant Notice
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