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ADSP21161 EZ-KIT Lite Frequency Modulation Demo

Analog Devices, Inc.
DSP Division
Three Technology Way
P.O. Box 9106
Norwood, MA 02062

Date Created:	8/15/01

Files contained in this directory:

21161_EZKIT_Lite.ldf		Linker Description File
FM_Modulation.dpj		Visual DSP++ 2.0 Project File
AD1836_reg_init_viaSPORTs.asm	Source for initializing AD1836 codec
AD1852_SPI_init.asm		Source for initializing AD1852 codec
Clear_SPT_regs.asm		Subroutines to clear SPORT1 registers
Init_21161_EZKit.asm		Source for main routine
ISR_table.asm			Interrupt Vector Table
SDRAM_initialization.asm	Initialize External Memory
SPORT02_TDM_Initialization.asm	Initialize SPORTS 0 & 2
SPT0_ISR_1836_Processing.asm	Interrupt Routine for SPT0
FM_Modulation.asm		Source file for subroutine
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CONTENTS

I.	FUNCTION/ALGORITHM DESCRIPTION
II.	IMPLEMENTATION DESCRIPTION
III.	OPERATION DESCRIPTION       


I. FUNCTION/ALGORITHM DESCRIPTION

The basis of this project is the 21161 talkthrough example. A processing subroutine
is inserted into the Talkthrough routine.

II.   IMPLEMENTATION DESCRIPTION

       FM_MODULATION.ASM -FM modulation using common sinusoidal wavetable                            
                                                                                                     
		 Developed for the 21161 EZ-KIT Lite Evaluation Board                                          
                                                            
       Based on Sec.8.1.3 of Introduction to Signal Processing                                       
       By S. J. Orfanidis - 1996, Prentice-Hall                                                      
       ISBN 0-13-209172-0                                                                            
                                                                                                                                                                                                  
       I/O equations: F(n) = c0 + Am * sin(2*pi*fm*t)                                                
                      y(n) = sin(2*pi*F(n)*n)                 
                      
       Why use frequency modulation?                                                                
       You can develop complex waveforms with rich sounds for synthesis applications by generating  
       frequency modulated signals, then combine them with other amplitude and frequency modulated  
       signals.                                                                                              
                                                                                                                                                                                                                                                                                                                                                                  

III.  OPERATION DESCRIPTION

- Plug in a microphone to Mic In and speakers to Ch 2 (Line Out)on the 21161 Ezkit Lite
- Open the project "FM_Modulation.dpj" in the VisualDSP++ Integrated Development Environment (IDE).
- Under the "Project" menu, select "Build Project".
- Open a ADSP21161 EZ-KIT Lite session in the VisualDSP++ Debugger.
- Load "FM_Modulation.dxe"
- Run the Project and speak into the microphone and hear the generated effect.
- Use the IRQ1 and IRQ2 pushbuttons to change the effect settings.