readme.txt

Wave Digital Filtering Using the MSP430

// ****************************************************************************
// This file the usage of the zip file slaa331.zip. included with the application 
// report "Wave Digital Filtering Using the MSP430"
//*****************************************************************************

The package slaa331.zip contains the following

1. 3 C-language files 
   wdf_ex1.c, wdf_ex2.c and wdf_ex3.c
     
2. 4 MSP430 Assembly files 
    wdf_ex1_asm.s43, wdf_ex2_asm.s43, wdf_ex3_asm.s43 and dco.s43   

3. The tool that gives the coefficients: wdf_coeff.exe
     
     Each of the three C-language files is used to generate the results obtained and depicted in the plots of the Application Report. 
       
Procedure to run the tests: 

Example 1: Low-pass Filtering

1. Create a new project on the IAR Embedded Workbench Ver 3.41A 
   Include wdf_ex1.c, wdf_ex1_asm.s43 and dco.s43 in the current project. 
  
2. From the project options choose the MSP430FG439 device from the list.

3. Choose the FET Debugger or the Simulator from the project options.

4. Build the project.

5. Select the Terminal I/0 if results need to be seen. 
     

Example 2: High-pass Filtering

1. Create a new project on the IAR Embedded Workbench Ver 3.41A 
   Include wdf_ex2.c, wdf_ex2_asm.s43 and dco.s43 in the current project. 
  
2. From the project options choose the MSP430FG439 device from the list.

3. Choose the FET Debugger or the Simulator from the project options.

4. Build the project.

5. Select the Terminal I/0 if results need to be seen. 

Example 2: Band-pass Filtering

1. Create a new project on the IAR Embedded Workbench Ver 3.41A 
   Include wdf_ex3.c, wdf_ex3_asm.s43 and dco.s43 in the current project. 
  
2. From the project options choose the MSP430FG439 device from the list.

3. Choose the FET Debugger or the Simulator from the project options.

4. Build the project.

5. Select the Terminal I/0 if results need to be seen. 
   
   
Procedure to run the tool wdf_coeff.exe

1. Double click on the tool wdf_coeff.exe 
2. The tool outputs few input specifications
     "Enter response type LP or HP" ==> Enter LP / HP
     "Enter filter design name Cheby, Butter or Ellip"==> Cheby/ Butter/ Ellip
     "Enter filter structure Normal or Birec"==> Normal/ Birec
     "Enter pass band edge frequency"==> "Enter value in Hz"
     "Enter stop band edge frequency"==> "Enter value in Hz", For HPF, this value is less than pass band edge frequency
     "Enter sampling frequency"==> "Enter value in Hz", This value should satisfy the Nyquist criterion
     "Enter pass band ripple in dB"==>"Enter value in dB", typical less than 1
     "Enter stop band attenuation in dB"==> "Enter value in dB", typical greater than 30
     "Enter design margin"==> "Enter value", Value between 0 and 1, typically 0.2	
     "Enter number of bits for binary representation"==> "Enter number", typically 12 to 16

Any other value entered that is logically incorrect does not display any error but gives erroneous results. Please read the document for further understanding of correct filter specifications. 

The order, gamma filter coefficients, adaptor type and the alpha coefficeints in binary and CSD is the output written in the file coeff.dat, which is automatically generated at the execution of the executable.