05-11-2012, 03:34 PM
Analyzing Target System Energy Consumption in Code Composer Studio™ IDE
[attachment=38189]
ABSTRACT
In the world of portable electronics, one of the key care-abouts for consumers is the time
they can operate their devices on battery. A top priority therefore in the portable
electronics industry is to develop “low-power” solutions. To enable our customers, the
portable electronic device providers, to succeed in this endeavor, TI has developed tooling
to measure power consumption on customer target systems and has integrated this
capability into Code Composer Studio to allow users to understand and address power
issues early in the product development lifecycle.
This application note introduces how to setup an environment for measuring power via
Code Composer Studio; some helpful tips on designing target systems that are conducive
to more accurate power measurement; how to instrument your application for power
measurement and visualize energy/function utilization.
Introduction
This application report has been developed as a high-level introduction to guide users through
the process of understanding how to measure and profile energy consumption on their own
target systems. While the methodology is such that all analysis is done with respect to the user’s
target application, there is no restriction on where, physically, power is measured on your target
board. That is to say, you can measure power with respect to the board supply, the digital signal
processor (DSP) core supply, the input/output (I/O) supply, etc. The data that gets visualized
though is always with respect to areas in your target application.
The two areas of concern for most are: understanding peak power (what is the maximum current
drawn by the system at any particular time) and understanding average energy consumption
(how much current is drawn over a period of time). The CCS Power Analyzer provides both
these capabilities, though the accuracy of the information is dependant on where on the target
you are measuring, the presence of decoupling capacitors, whether you use a wire loop and
current probe for current measurement or a sense resistor, the length of the range of code you
are measuring, etc.
This solution provides multiple modes of measurement. Each mode has its positives and
negatives. Depending on where you are in your power understanding lifecycle, you must choose
the appropriate mode. While some modes preserve the real–time constraints of your application,
they may not provide the granularity of information you need (single–range real time mode).
Whereas multifunction non–real time mode puts no restrictions on the number of functions
instrumented and allows for higher sampling rates, it stops the target, and any real–time
constraints your application has will be lost.
CCS Power Analyzer Plug-in and support software
The CCS Power Analyzer Plug-in is available via a CCS Update Advisor patch or in the
TMS320C5510 DSP Starter Kit (DSK). It will automatically register into Code Composer Studio.
The plug–in provides the capability to instrument your application in various modes and display
the measured data. It also allows you to save the measured data to a Comma Separated Value
(CSV) file that can be imported into standard spreadsheet and data analysis software packages.
Included with the plug–in are target specific support libraries that must be added to the project
that is to be analyzed. This support software is responsible for coordinating code execution and
power and peripheral data capture. You will need to use a different library, based on your choice
of profiling method and memory model.
Setting Up the Current Probe
The user should follow the setup procedure for the current probe and amplifier as described in
the manufacturer’s instruction manual. After completing the calibration, the user will need to
adjust the output (current/div) setting of the current amplifier, to maximize the output of the
current measurement. The current/division setting of the current amplifier must be input into the
Power Analyzer Plug–In.
Emulation Logic and Run Free
Emulation logic on the target system consumes some power. This power is measured with the
applications power in MR and MNR modes. These modes need the emulation logic because
they use breakpoints (MNR) and RTDX (MR). Since the power consumed by the emulation logic
is included with the power measured by the Power Analyzer, these measurements cannot be
considered absolute, rather they are relative.
It is possible to turn off the emulation logic in SR mode. After instrumenting and loading your
program, run it with the run free command on the debug menu instead of the normal run
command. The run free command turns off the emulation logic and then instructs the target
processor to run. There is one minor caveat, it takes some time for the emulation logic to be
completely shut off. Therefore if the range you're measuring is at the very beginning of the
program you should include a short delay loop before the range you're measuring begins.
Saving Results
The Power Analyzer allows you to save captured measurements (results and raw data) to a
Comma Separated Value (CSV) file. This file can then be imported into Excel, Lotus, and many
other applications.
[attachment=38189]
ABSTRACT
In the world of portable electronics, one of the key care-abouts for consumers is the time
they can operate their devices on battery. A top priority therefore in the portable
electronics industry is to develop “low-power” solutions. To enable our customers, the
portable electronic device providers, to succeed in this endeavor, TI has developed tooling
to measure power consumption on customer target systems and has integrated this
capability into Code Composer Studio to allow users to understand and address power
issues early in the product development lifecycle.
This application note introduces how to setup an environment for measuring power via
Code Composer Studio; some helpful tips on designing target systems that are conducive
to more accurate power measurement; how to instrument your application for power
measurement and visualize energy/function utilization.
Introduction
This application report has been developed as a high-level introduction to guide users through
the process of understanding how to measure and profile energy consumption on their own
target systems. While the methodology is such that all analysis is done with respect to the user’s
target application, there is no restriction on where, physically, power is measured on your target
board. That is to say, you can measure power with respect to the board supply, the digital signal
processor (DSP) core supply, the input/output (I/O) supply, etc. The data that gets visualized
though is always with respect to areas in your target application.
The two areas of concern for most are: understanding peak power (what is the maximum current
drawn by the system at any particular time) and understanding average energy consumption
(how much current is drawn over a period of time). The CCS Power Analyzer provides both
these capabilities, though the accuracy of the information is dependant on where on the target
you are measuring, the presence of decoupling capacitors, whether you use a wire loop and
current probe for current measurement or a sense resistor, the length of the range of code you
are measuring, etc.
This solution provides multiple modes of measurement. Each mode has its positives and
negatives. Depending on where you are in your power understanding lifecycle, you must choose
the appropriate mode. While some modes preserve the real–time constraints of your application,
they may not provide the granularity of information you need (single–range real time mode).
Whereas multifunction non–real time mode puts no restrictions on the number of functions
instrumented and allows for higher sampling rates, it stops the target, and any real–time
constraints your application has will be lost.
CCS Power Analyzer Plug-in and support software
The CCS Power Analyzer Plug-in is available via a CCS Update Advisor patch or in the
TMS320C5510 DSP Starter Kit (DSK). It will automatically register into Code Composer Studio.
The plug–in provides the capability to instrument your application in various modes and display
the measured data. It also allows you to save the measured data to a Comma Separated Value
(CSV) file that can be imported into standard spreadsheet and data analysis software packages.
Included with the plug–in are target specific support libraries that must be added to the project
that is to be analyzed. This support software is responsible for coordinating code execution and
power and peripheral data capture. You will need to use a different library, based on your choice
of profiling method and memory model.
Setting Up the Current Probe
The user should follow the setup procedure for the current probe and amplifier as described in
the manufacturer’s instruction manual. After completing the calibration, the user will need to
adjust the output (current/div) setting of the current amplifier, to maximize the output of the
current measurement. The current/division setting of the current amplifier must be input into the
Power Analyzer Plug–In.
Emulation Logic and Run Free
Emulation logic on the target system consumes some power. This power is measured with the
applications power in MR and MNR modes. These modes need the emulation logic because
they use breakpoints (MNR) and RTDX (MR). Since the power consumed by the emulation logic
is included with the power measured by the Power Analyzer, these measurements cannot be
considered absolute, rather they are relative.
It is possible to turn off the emulation logic in SR mode. After instrumenting and loading your
program, run it with the run free command on the debug menu instead of the normal run
command. The run free command turns off the emulation logic and then instructs the target
processor to run. There is one minor caveat, it takes some time for the emulation logic to be
completely shut off. Therefore if the range you're measuring is at the very beginning of the
program you should include a short delay loop before the range you're measuring begins.
Saving Results
The Power Analyzer allows you to save captured measurements (results and raw data) to a
Comma Separated Value (CSV) file. This file can then be imported into Excel, Lotus, and many
other applications.