General EE
Name/Title of Material: Audio Effects using TMS320C6711 and Audio Daughter Card
Author: Richard Sikora
E-mail: richard@sikora.demon.co.uk
DSP device on which material is based: TMS320C6000
DSP development tools used in material: TMS320C6711 DSK, Audio Daughter Card
Type of Materials: Lab Exercises
Application area: Audio
Type/level of lab: General EE, Non-EE, Introductory undergraduate, Advanced undergraduate, TMS320C6000
Is the Lab a primary focus of the course? Yes
Type of course for which material was developed: Application
Language in which material is written: English
Developed/Last Updated Date: 18th March 2002
File type: Code Composer Studio Project
File: Audio Effects Using C6711 & ADC.zip (278K)
Computer Language on which the material is based: C
Description of item(s)/value to others: A series of 8 audio applications using the Audio Daughter Card and the TMS320C6711 DSK. Illustrates the use of DSP in audio setting. Applications are controlled by user switches on DSK and use LEDS as bargraph.
Additional equipment required: CD player with cable, multi-media computer loudspeakers. Signal generator or electric guitar.
- Application 1. Alien voices. Using ring-modulation to produce sum and difference frequencies, as used in science- fiction TV/films.
- Application 2. Delays and Echo. Using buffers to generate delayed playback (as used on radio phone-ins). Introduction to Finite Impulse Response (FIR) configuration.
- Application 3. Electronic Crossover. Using FIR filters to divide audio signal into bass and treble.
Application 4. Guitar Effects. Reverberation, treble boost and distortion for electric guitar.
- Application 5. Guitar Tuner. Uses adaptive filter to identify 6 notes of guitar strings.
- Application 6. Record and Playback. Use buffers as to record and playback voice / music. Playback at half-speed and double speed to introduce concepts of decimation and interpolation.
- Application 7. Reverberation. Simulation of echoing room / auditorium using feedback filter. Introduction to Infinite Impulse Response (IIR) filter configuration.
- Application 8. Signal generator. Generates sine waves sweeping between 60 Hz to 12 kHz to act as test wave forms for filters etc. Sine wave forms generated using recursive equation.
Name/Title of Material: Simple Experiments using TMS320LF2407
Author: Richard Sikora
E-mail: richard@sikora.demon.co.uk
DSP device on which material is based: TMS320C2000
DSP development tools used in material: TMS320F2407 DSK, TMS320F2407 EVM
Type of Materials: Tutorials with sample code
Application area: Control, General Signal Processing
Type/level of lab: General EE, Non-EE, Introductory undergraduate, Advanced undergraduate, TMS320C2000
Is the Lab a primary focus of the course? Yes
Type of course for which material was developed: Application
Language in which material is written: English
Developed/Last Updated Date: 18th March 2002
File types: MS Word, C source files
File: TMS320F2407 Applications.zip (6M)
Computer Language on which the material is based: C, Assembler
Description of item(s)/value to others: A series of simple applications of the TMS320LF2407. Uses the 2407 DSK to control a stepper motor, dc motor, generate sine waves using PWM, FIR and IIR filters.
Code written mostly in C with some in assembly language for speed.
A 12V 1A DC power supply and an oscilloscope would be useful.
Schematic provided of some basic electronic components costing only a few dollars.
Name/Title of Material: Assembly Language Tutorials for the TMS320C2000 Family
Author: Richard Sikora
E-mail: richard@sikora.demon.co.uk
DSP device on which material is based: TMS320C2000
DSP development tools used in material: TMS320F2407 DSK, TMS320F243 DSK, TMS320F2407 EVM, TMS320F243 EVM
Type of Materials: Tutorials with sample code
Application area: Control, General Signal Processing
Type/level of lab: General EE, Non-EE, Introductory undergraduate, TMS320C2000
Is the Lab a primary focus of the course? No
Type of course for which material was developed:Application
Language in which material is written: English
Developed/Last Updated Date: 18th March 2002
File types: MS Word
File: TMS320F2000 Tutorials.zip (2.4M)
Computer Language on which the material is based: C, Assembler
Description of item(s)/value to others: A series of 10 assembly language tutorials with code. Tested on TMS320F243 DSK, but applicable to all the 'C2000 family. Simple experiments to illustrate use most common assembly language instructions e.g. moving data, adding, multiplication with accumulation. Add on components for DSK will only cost a few dollars. Assumes no previous knowledge of assembly language programming, but does use some basic C code.
Name/Title of material: Hands-on TMS320LF2407 in C
Author: Frank Bormann
University: University of Applied Sciences Zwickau
E-mail: Frank.Bormann@fh-zwickau.de
DSP device on which material is based: TMS320C2000
DSP development tools used in material: TMS320C243 EVM, TMS320C2407 EVM
Type of Materials: Lab Exercises
Application Area: General Signal Processing
Type/level of lab: General EE, Introductory Undergraduate, Introductory graduate, TMS320C2000
Is the Lab a primary focus of the course? Yes
Type of course for which material was developed: Lab
Language in which material is written: English
Developed/Last Updated Date: June 2000
Course URL: http://www.fh-zwickau.de/tutorial/dsp
File type: Adobe Acrobat PDF, HTML, C/Assembly/Executable
File: F24x EVM Labs.zip (2.4MB)
Computer Language on which the material is based: C
Description of item(s)/value to others: The labs are based on the TMS320LF2407 EVM / TMS320F243 EVM. They involve two add-on boards for these EVMs. They include LED's,Switches,Potentiometers and an SPI-EEPROM. The aim of the lab is to get all the internal peripherals of this DSP to work. The labs are based on CodeComposer and are programmed in C. The additional boards are manufactured by our university.
Name/Title of Material: Use of Audio Daughter Card with C6711 DSK
Author: Rulph Chassaing
University: University of Massachusetts Dartmouth
Email: chassaing@msn.com
DSP Device on which this Material is Based: TMS320C6000
DSP Development Tools Used in Material: TMS320C6711 DSK
Type of Materials: Lab Exercises
Application Area: Audio, General Signal Processing
Type/Level of Lab: General EE, Non-EE, Advanced undergraduate, Introductory graduate, TMS320C6000
Is the Lab a Primary Focus of the Course?: Yes
Type of course for which material was developed: Lab
Language in which Material is Written: English
Developed/Last Updated Date: January 2002
File Type: Executable, C/Assembly Code
File: AudioDC Examples.zip (28.5K)
Computer Language on which Material is based: C, C++
Description of item(s)/value to others: Two examples using TI's stereo codec PCM3003-based Audio Daughter Card with C6711 DSK. Taken from book "DSP Applications Using C and the TMS320C6x DSK" by Rulph Chassaing.
- "Loop" with output=delayed input
- FIR filter implementation
Name/Title of material: An Introduction to Digital Signal Processors
Author: Bruno Paillard
University: Universite de Sherbrooke
E-mail: Bruno.Paillard@USherbrooke.ca
DSP device on which material is based: TMS320C5000
DSP development tools used in material: Signal Ranger DSP board
Type of Materials: Introductory Book
Type/level of lab: General EE, Introductory Graduate, TMS320C5000
Is the Lab a primary focus of the course? No
Type of course for which material was developed: Lab
Language in which material is written: English
Developed/Last Updated Date: February 2002
File type: Adobe Acrobat PDF
File: C5000 Course Manual (English).zip (3.1MB)
Computer Language on which the material is based: Assembler
Description of item(s)/value to others: (New edition, written in English) This book has been written to support an introductory course on Microprocessors and Microprocessor applications. The focus is on embedded systems in general, and systems incorporating Digital Signal Processing functions in particular.
The book covers the following topics:
- Short history of the microprocessor
- Systems architecture
- Boolean algebra and fixed point computation
- Development tools
- The TMS320VC5402
- Software development methodology for embedded systems
Name/Title of material: FIR Filters
Author: Mohamed El-Tanany
University: Carleton University
E-mail: tanany@sce.carleton.ca
DSP device on which material is based: TMS320C5000
DSP development tools used in material: TMS320C54x EVM
Type of Materials: Lab Exercises
Type/level of lab: General EE, Introductory Undergraduate, TMS320C5000
Is the Lab a primary focus of the course? Yes
Type of course for which material was developed: Lab
Language in which material is written: English
Developed/Last Updated Date: August 2001
File type: Adobe Acrobat PDF, Matlab, Executable, Assembly
File: FIR Lab.zip (132K)
Computer Language on which the material is based: Assembler
Description of item(s)/value to others: This lab is meant to explore the basic characteristics and design of FIR filters. Included are all the files needed to run the experiment in addition to the Matlab files needed for the design, plus the lab/assignment writing as it was given to our students, plus two sets of lecture notes.
Name/Title of material: Une introduction aux processeurs de traitement du signal
Author: Bruno Paillard
University: Universite de Sherbrooke
E-mail: Bruno.Paillard@USherbrooke.ca
DSP device on which material is based: TMS320C5000
DSP development tools used in material: Third Party tools (Signal Ranger DSP Board)
Type of Materials: Introductory Book
Application area: General Microprocessors
Type/level of lab: General EE, Introductory undergraduate, TMS320C5000
Is the Lab a primary focus of the course? No
Type of course for which material was developed: Lab
Language in which material is written: French
Developed/Last Updated Date: May 2001
File type: Adobe Acrobat PDF
File: introduction_dsp.zip (2.4M)
Computer Language on which the material is based: Assembler
Description of item(s)/value to others: This book has been written to support an introductory course on Microprocessors and Microprocessor implementation. The focus is on embedded systems in general, and systems incorporating Digital Signal Processing functions in particular.
The book covers the following topics:
- Short history of the microprocessor
- Systems architecture
- Boolean algebra and fixed point computation
- Development tools
- The TMS320VC5402
- Software development methodology for embedded systems
Name/Title of Material: winDSK
Author: Michael Morrow
University: University of Wisconsin-Madison
Email: morrow@engr.wisc.edu
DSP Platform on which Material is Based: TMS320C3x
DSP Device on which Material is Based: TMS320C3x
DSP Development Tools Used in Material: TMS320C3x DSK
Type of Material: Educational Software
Application Area: Audio, General Signal Processing
Type/Level of Lab: General EE, Non-EE, Introductory Undergraduate, TMS320C3x
Is the Lab a Primary Focus of the Course? (Yes/No): No
Major Emphasis of Course for which Material was Developed: Application
Language in which Material is Written: English
Developed/Last Updated Date: November 21, 2000
File Types: Executable File
File: winDSK_1_6_1_2.zip (1.3Mb)
Computer Language in which Material is Written: Executable
Description/Value to Others: winDSK is a Windows 9X/NT demonstration and debugging program for use with the TMS320C31 DSK.
Supported demonstrations include; sampling/quantization effects, oscilloscope/spectrum analyzer, arbitrary waveform generator, notch/bandpass filter, graphic equalizer, audio effects, and guitar synthesizer.
winDSK also provides a tool for debugging applications which use a PC host to control the DSK, and includes an EEPROM programmer utility to develop stand-alone applications.
Extract the files to a temporary directory, and run setup.exe. The winDSK help files contain information on operating the program.
Name/Title of Material: winDSK6
Author: Michael Morrow
University: University of Wisconsin-Madison
Email:morrow@ieee.org
DSP Platform on which Material is Based: TMS320C6000
DSP Device on which Material is Based: TMS320C6000
DSP Development Tools Used in Material: TMS320C6211 DSK, TMS320C6711 DSK
Type of Material: Educational Software
Application Area: Audio, General Signal Processing
Type/Level of Lab: General EE, Non-EE, Introductory Undergraduate, TMS320C6000
Is the Lab a Primary Focus of the Course?: No
Major Emphasis of Course for which Material was Developed: Application
Language in which Material is Written: English
Developed/Last Updated Date: August 26, 2002
File Types: Executable File
File:winDSK6.zip (1184K)
Computer Language in which Material is Written: Executable
Description/Value to Others: winDSK6 is a Windows 9X/NT/2000 demonstration and debugging program for use with the TMS320C6X11 DSK. It supports a number of analog interfaces in addition to the DSK's onboard codec, including several stereo codec daughtercards and the Texas Instruments THS1206 EVM.
Supported demonstrations include; sampling/quantization effects, oscilloscope/spectrum analyzer, arbitrary waveform generator, notch/bandpass filter, graphic equalizer, audio effects, DTMF generator and guitar synthesizer. An HPI Interface application facilitates the development and debugging of host PC Windows applications that communicate with the DSK.
Extract the files to a temporary directory, and run setup.exe. The winDSK6 help files contain information on operating the program. winDSK6 does not require Code Composer Studio for operation.
First Name: Richard
Last Name: Sikora
University: None
E-mail: richard@sikora.demon.co.uk
DSP device on which material is based: TMS320C5000
DSP development tools used in material: TMS320C5402 DSK
Type of Materials: Lab exercises
Application area: Audio | General Signal Processing | Speech
Type/level of lab: General EE | Non-EE | Introductory undergraduate | TMS320C5000
Is the Lab a primary focus of the course? Yes
Name/Title of material: Configuring the Audio Daughter Card with TMS320C5402 DSK
Type of course for which material was developed: Lab
Language in which material is written: English
Developed/Last Updated Date: 11/11/02
File type: Archived Source File | MS Word
File: Template for Audio Daughter Card with TMS320C5402 DSK.ZIP (50k)
Computer Language on which the material is based: C | Assembler
Description of item(s)/value to others:
Template for an audio project for use with the TMS320C5402 DSK and Code Composer Studio V1.20.
Requires a CD player / walkman and headphones / powered computer speakers. A signal generator if available would be useful.
Code provided in C.
Configures the TMS320C5402 DSK with the Audio Daughter Card for audio usage. Allows the student to use the 2 user switches as inputs and the 3 LEDs as a bargraph display.
Intended to be used as a starting point for audio experiments.
First Name: Richard
Last Name: Sikora
University: None
E-mail: richard@sikora.demon.co.uk
DSP device on which material is based: TMS320C5000
DSP development tools used in material: TMS320C5402 DSKOther TMS320C5416 DSK
Type of Materials: Lab exercises
Application area: Audio
Type/level of lab: General EE | Non-EE | Introductory undergraduate | TMS320C5000
Is the Lab a primary focus of the course? Yes
Name/Title of material: Audio Experiments 1 - 4 for the TMS320C5416 DSK
Type of course for which material was developed: Lab
Language in which material is written: English
Developed/Last Updated Date: 11/11/02
File type: Executable File | MS Word
File: TMS320C5416 DSK Laboratories 1 - 4.ZIP (320K)
Computer Language on which the material is based: C | Assembler
Description of item(s)/value to others:
The first four in a series of practical experiments to process audio using the TMS320C5416 DSK and Code Composer Studio V2.0. Requires a CD player / walkman and headphones / powered computer speakers. If available, a signal generator would be useful.
Code is written mostly in C and C5400 assembly language where speed is required. Users the 4 user switches on the TMS320C5416 DSK and configures the 4 LEDs as a bargraph display.
The laboratories allow the student to find out the answers to the following questions by practical experiment:
Laboratory 1. What sampling rate is required for
a) music?
b) speech?
The C code provided allows 16 different sampling rates from 24 kHz down to 1 kHz to be selected using the user switches on the DSK.
Laboratory 2. How many sampling bits are required for acceptable quality a) music and b) speech?
Sampling can be adjusted between 16 bits and 5 bits using the user switches on the DSK.
Laboratory 3. In order to divide music into bass and treble, a Finite Impulse Response (FIR) filter can be used. Which of the following types of FIR filter gives the best sound: Rectangular, Hamming, Hanning, Blackman and Kaiser?
Uses 15 different configurations of high pass and low pass FIR filters, controlled by the user switches on the DSK.
Laboratory 4. When using a Finite Impulse Reponse Filter (FIR), how many coefficients are required for hi-fi sound quality? How many coefficients are required for acceptable speech quality?
Provides 15 different configurations of low pass and high pass FIR filters with different numbers of coefficients.
First Name: Richard
Last Name: Sikora
University: None
E-mail: richard@sikora.demon.co.uk
DSP device on which material is based: TMS320C5000
DSP development tools used in material: TMS320C5402 DSKOther TMS320C5416 DSK
Type of Materials: Lab exercises
Application area: Audio | General Signal Processing | Speech
Type/level of lab: General EE | Non-EE | Introductory undergraduate | TMS320C5000
Is the Lab a primary focus of the course? Yes
Name/Title of material: Audio Applications 1 - 4 for TMS320C5416 DSK
Type of course for which material was developed: Lab
Language in which material is written: English
Developed/Last Updated Date: 11/11/02
File type: Archived Source File | MS Word
File: TMS320C5416 DSK Applications 1 - 4.ZIP (320K)
Computer Language on which the material is based: C | Assembler
Description of item(s)/value to others:
Four audio examples for use with the TMS320C5416 DSK and Code Composer Studio V2.0.
Requires a CD player / walkman and headphones / powered computer speakers. A signal generator if available would be useful.
Code provided mostly in C and 'C5400 assembly language where speed is required.
Thes applications could be applied to TMS320C5402 DSK, although this has only 2 user switches and 3 LEDs.
Application 1. Template for an audio project.
Configures the TMS320C5416 DSK for audio usage. Allows the student to use the 4 user switches as inputs and the 4 LEDs as a bargraph display.
Application 2. Delays and Echo.
Sets up the TMS320C5416 DSK for delays and echo to simulate a large auditorium. Uses circular buffers and introduces configuration also used for Finite Impulse Response (FIR) filters.
Application 3. Reverberation.
Simulates simple and multiple reflections off walls to simulate different types of rooms. Uses circular buffers and introduces the configuration used for Infinite Impulse Response (IIR) filters.
Application 4. Electronic Crossover.
Divides the audio signal into bass and treble. The frequency at which bass and treble are separated is adjusted using the 4 user switches in the range 100 Hz to 6400 Hz. Uses FIR filters.
Title: TMS320C5416 DSK Audio Applications 1-4
Author: Richard Sikora
University: None
E-mail: richard@sikora.demon.co.uk
DSP device on which material is based: TMS320C5000
DSP development tools used in material: TMS320C5402 DSK, MS320C5416 DSK
Type of Materials: Lab exercises
Application area: Audio, General Signal Processing, Speech
Type/level of lab: General EE, Non-EE, Introductory undergraduate, Introductory graduate, TMS320C5000
Is the Lab a primary focus of the course? Yes
Type of course for which material was developed: Lab
Language in which material is written: English
Developed/Last Updated Date: 20th January 2003
File type: Archived Source File, Code Composer Studio Project, MS Word
File: TMS320C5416 Laboratories 1-4.zip (888 KB), TMS320C5416 Applications 1-4.zip (940 KB)
Computer Language on which the material is based: C, Assembler, Matlab
Description of item(s)/value to others:
Four practical audio applications of digital signal processing (DSP) using the TMS320C5416 DSK. These can also be used as the basis of laboratories.
Equipment Required:
TMS320C5416 DSK
CD player or walkman
Computer loudspeakers
Microphone
Application 1. Template
A template for an audio project. Sets up the 4 LEDs on the TMS320C5416 DSK as a bargraph and the 4 user switches to control the audio processing.
Application 2. Delays and Echo
Simulates the delays experienced in communications networks and the reflection of sound heard in a canyon. Introduces circular buffers and the configuration used for Finite Impulse Response (FIR) filters.
Application 3. Reverberation
Simulates single and multiple reflections of sound from the walls of a room or auditorium. Introduces the configuration used for Infinite Impulse Response (IIR) filters.
Application 4. Electronic Crossover
Divides an audio signal into bass and treble components for driving different loudspeakers using FIR filters. The user switches on the TMS320C5416 DSK select 15 different crossover frequencies between 300 Hz and 12800 Hz.
Title: TMS320C5416 DSK Audio Applications 5 - 8
Author: Richard Sikora
E-mail: richard@sikora.demon.co.uk
DSP device on which material is based: TMS320C5000
DSP development tools used in material: TMS320C5402 DSK, TMS320C5416 DSK
Type of Materials: Lab exercises
Application area: Audio, General Signal Processing, Speech
Type/level of lab: General EE, Non-EE, Introductory undergraduate, Introductory graduate, TMS320C5000
Is the Lab a primary focus of the course? Yes
Type of course for which material was developed: Lab
Language in which material is written: English
Developed/Last Updated Date: 20th January 2003
File type: Archived Source File, Code Composer Studio Project, MS Word
File: TMS320C5416 Laboratories 5-8.zip (1 MB), TMS320C5416 Applications 5-8.zip (2 MB)
Computer Language on which the material is based: C, Assembler, Matlab
Description of item(s)/value to others:
Four practical applications of digital signal processing (DSP) using the TMS320C5416 DSK. These can also be used as the basis of laboratories.
Equipment Required:
TMS320C5416 DSK
CD player or walkman and computer loudspeakers
Microphone
Touch telephone
Optionally, a signal generator to generate sine waves in the range 20 Hz to 50 kHz.
Application 5. Alien Voices
Uses ring modulation to alter the spectral content of speech and music. Widely used in science-fiction films and television to generate strange voices for aliens.
Application 6. Infinite Impulse Response (IIR) Filters
A collection of high pass, low pass, band pass and band stop filters for audio use. Can be used to boost or cut certain frequency bands from the audio spectrum.
Application 7. Goertzel Algorithm
A special case of the IIR filter used to identify the dual tones generated when the buttons of a touch tone telephone are pressed. Uses a microphone to pick up the sound of the telephone and shows the buttons pressed on the computer screen.
Application 8. Spectrum Analyser
Uses a Fast Fourier Transform (FFT) to analyse the power of specific bands in an audio signal.
Title: TMS320C5416 DSK Laboratories 9 - 12
Author: Richard Sikora
University: None
E-mail: richard@sikora.demon.co.uk
DSP device on which material is based: TMS320C5000
DSP development tools used in material: TMS320C5402 DSK, TMS320C5416 DSK
Type of Materials: Lab exercises
Application area: Audio, General Signal Processing, Speech
Type/level of lab: General EE, Non-EE, Introductory undergraduate, Introductory graduate, TMS320C5000
Is the Lab a primary focus of the course? Yes
Type of course for which material was developed: Lab
Language in which material is written: English
Developed/Last Updated Date: 20th January 2003
File type: Archived Source File, Code Composer Studio Project, MS Word
File: TMS320C5416 Applications 9-10.zip (651 KB)
Computer Language on which the material is based: C, Assembler, Matlab
Description of item(s)/value to others:
The third in a series of laboratories to allow the student to find out the answers to some questions about digital signal processing (DSP) by carrying out practical experiments using audio. Complete application code for the TMS320C5416 DSK is provided for each laboratory.
Equipment Required:
CD player or walkman
Computer loudspeakers
Optionally, a signal generator to generate sine waves in the range 20 Hz to 50 kHz.
To produce quantitative results for Laboratory 9, a digital frequency meter and/or a digital storage oscilloscope are required.
Laboratory 9. Comparison of Performance of C and Assembly code
For which of the following does assembly language offer a benefit in performance over C code:
a) Finite Impulse Response (FIR) filters
b) Infinite Impulse Response (IIR) filters
c) Adaptive filters?
Does the execution time of a Fast Fourier Transform (FFT) increase linearly or logarithmically with the number of points?
Laboratory 10. Decimation by Integer Amounts to Decrease Sampling Rate
How does reducing the sampling rate affect the audio quality?
Why is an anti-aliasing filter required?
Laboratory 11. Interpolation by Integer Amounts to Increase Sampling Rate
How does increasing the sampling rate affect audio quality?
Why is an anti-imaging filter required?
Laboratory 12. Noise Reduction Using Adaptive Filters and Notch Filters
In which cases would an IIR filter be used to remove noise from an audio signal?
In which cases would an adaptive filter be used to remove noise from an audio signal?
Title of Material: Signal Processing Lab, TUGraz
Author: Christian Feldbauer
University: Graz University of Technology
E-mail: feldbauer@inw.tugraz.at
DSP device on which material is based: TMS320C6000
DSP development tools used in material: TMS320C6711 DSK
Type of Materials: Lab exercises
Application Area: General Signal Processing
Type/Level of Lab: General EE, Advanced undergraduate, TMS320C6000
Is the Lab a primary focus of the course? Yes
Type of course for which material was developed: Lab
Language in which material is written: English
Developed/Last Updated Date: Apr. 2003
Course URL: http://spsc.inw.tugraz.at/courses/dsplab
File type: Adobe Acrobat PDF, Archived Source File
File: C6000 DSP Lab.zip (1.2MB)
Computer Language on which the material is based: C, Assembler, Matlab
Description of item: Laboratory course material (lab exercises and source code) for 6 labs. Experiments cover fundamental concepts of digital signal processing like sampling and aliasing, quantization in A/D conversion and in internal arithmetic operations, digital filter design and implementation, spectrum estimation and fast transforms, sampling-rate conversion and multi-rate processing. Application experiments address a selection of multi-media and digital communications problems where visual and auditory feedback is used to demonstrate the desired effects and artifacts of digital processing.
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