EC2306-DSP

www.vidyarthiplus.com

RAJALAKSHMI ENGINEERING COLLEGE

THANDALAM, CHENNAI- 602105

Department of Electronics and Communication Engineering

EC2306 - DIGITAL SIGNAL PROCESSING

LABORATORY MANUAL

EC2306 DIGITAL SIGNAL PROCESSING LAB

USING TMS320C5X/TMS320C 67XX/ADSP 218X/219X/BS531/532/561

1. Study of various addressing modes of DSP using simple programming examples 2. Implementation of Linear and Circular Convolution 3. Sampling of input signal and display 4. Waveform generation 5. Implementation of FIR filter

USING MATLAB

1. Generation of Signals 2. Linear and circular convolution of two sequences 3. Sampling and effect of aliasing 4. Design of FIR filters 5. Design of IIR filters 6. Calculation of FFT of a signal 7. Decimation by polyphase decomposition.

1. MATLAB PROGRAMS

1. LINEAR CONVOLUTION

clc;clear all;close all;

x=input('ENTER THE FIRST SEQUENCE ');

h=input('ENTER THE SECOND SEQUENCE ');

y=conv(x,h);

stem(y);

xlabel('Amplitude---->');

ylabel('time----->');

title('LINEAR CONVOLUTION');

2. Program illustrates the design of a Butterworth bandstop filter.

% Program P7_1

% Design of a Butterworth Bandstop Digital Filter

Ws = [0.4 0.6]; Wp = [0.3 0.7]; Rp = 0.4; Rs = 50;

% Estimate the Filter Order

[N1, Wn1] = buttord(Wp, Ws, Rp, Rs);

% Design the Filter

[num,den] = butter(N1,Wn1,’stop’);

% Display the transfer function

disp(’Numerator coefficients are ’);disp(num);

disp(’Denominator coefficients are ’);disp(den);

% Compute the gain response

[g,w] = gain(num,den);

% Plot the gain response

plot(w/pi,g);grid

axis([0 1 -60 5]);

xlabel(’\omega /\pi’); ylabel(’Gain, dB’);

title(’Gain Response of a Butterworth Bandstop Filter’);

3. To implement a causal IIR filter implemented in the Direct Form II structure,

the function direct2 given below can be employed.

function [y,sf] = direct2(p,d,x,si);

% Y = DIRECT2(P,D,X) filters input data vector X with

% the filter described by vectors P and D to create the

% filtered data Y. The filter is a "Direct Form II"

% implementation of the difference equation:

% y(n) = p(1)*x(n) + p(2)*x(n-1) + ... + p(np+1)*x(n-np)

% - d(2)*y(n-1) - ... - d(nd+1)*y(n-nd)

% [Y,SF] = DIRECT2(P,D,X,SI) gives access to initial and

% final conditions, SI and SF, of the delays.

dlen = length(d); plen = length(p);

N = max(dlen,plen); M = length(x);

sf = zeros(1,N-1); y = zeros(1,M);

if nargin ~= 3,

sf = si;

end

if dlen < plen,

d = [d zeros(1,plen - dlen)];

else

p = [p zeros(1, dlen - plen)];

end

p = p/d(1); d = d/d(1);

for n = 1:M;

wnew = [1 -d(2:N)]*[x(n) sf]’;

K = [wnew sf];

y(n) = K*p’;

sf = [wnew sf(1:N-2)];

end

4. Program illustrates the design of a causal IIR filter, its simulation in transposed

Direct Form II, and its application in filtering a signal.

% Program P8_3

% Illustration of Filtering by an IIR Filter

%

clf;

% Generate the input sequence

k = 0:50;

w2 = 0.7*pi;w1 = 0.2*pi;

x1 = 1.5*cos(w1*k); x2 = 2*cos(w2*k);

x = x1+x2;

% Determine the filter transfer function

[N, Wn] = ellipord(0.25, 0.55, 0.5, 50);

[num, den] = ellip(N,0.5, 50,Wn);

% Generate the output sequence

y = filter(num,den,x);

% Plot the input and the output sequences

subplot(2,1,1);

stem(k,x); axis([0 50 -4 4]);

xlabel(’Time index n’); ylabel(’Amplitude’);

title(’Input Sequence’);

subplot(2,1,2);

stem(k,y); axis([0 50 -4 4]);

xlabel(’Time index n’); ylabel(’Amplitude’);

title(’Output Sequence’);

5. Program up-sampler.

% Illustration of Up-Sampling by an Integer Factor

%

clf;

n = 0:50;

x = sin(2*pi*0.12*n);

y = zeros(1, 3*length(x));

y([1: 3: length(y)]) = x;

subplot(2,1,1)

stem(n,x);


xlabel(’Time index n’);ylabel(’Amplitude’);

subplot(2,1,2)

stem(n,y(1:length(x)));


xlabel(’Time index n’);ylabel(’Amplitude’);

6. Illustration of Down-Sampling by an Integer Factor

clf;

n = 0: 49;

m = 0: 50*3 - 1;

x = sin(2*pi*0.042*m);

y = x([1: 3: length(x)]);

subplot(2,1,1)

stem(n, x(1:50)); axis([0 50 -1.2 1.2]);


xlabel(’Time index n’);

ylabel(’Amplitude’);

subplot(2,1,2)

stem(n, y); axis([0 50 -1.2 1.2]);


xlabel(’Time index n’);

ylabel(’Amplitude’);

7. Use fir2 to create a bandlimited input sequence

clf;

freq = [0 0.45 0.5 1];

mag = [0 1 0 0];

x = fir2(99, freq, mag);

% Evaluate and plot the input spectrum

[Xz, w] = freqz(x, 1, 512, ’whole’);

subplot(2,1,1);

plot(w/pi, abs(Xz)); axis([0 1 0 1]); grid

xlabel(’\omega/\pi’); ylabel(’Magnitude’);

title(’Input Spectrum’);

subplot(2,1,2);

% Generate the up-sampled sequence

L = input(’Type in the up-sampling factor = ’);

y = zeros(1, L*length(x));

y([1: L: length(y)]) = x;

% Evaluate and plot the output spectrum

[Yz, w] = freqz(y, 1, 512, ’whole’);

plot(w/pi, abs(Yz)); axis([0 1 0 1]); grid


title(’Output Spectrum’);

8. Program P10 4 can be employed to study the frequency-domain properties of the

downsampler.

% Program P10_4

% Effect of Down-sampling in the Frequency Domain

% Use fir2 to create a bandlimited input sequence

clf;

freq = [0 0.42 0.48 1]; mag = [0 1 0 0];

x = fir2(101, freq, mag);

% Evaluate and plot the input spectrum

[Xz, w] = freqz(x, 1, 512);

subplot(2,1,1);

plot(w/pi, abs(Xz)); grid


title(’Input Spectrum’);

% Generate the down-sampled sequence

M = input(’Type in the down-sampling factor = ’);

y = x([1: M: length(x)]);

% Evaluate and plot the output spectrum

[Yz, w] = freqz(y, 1, 512);

subplot(2,1,2);

plot(w/pi, abs(Yz)); grid


title(’Output Spectrum’);

9. FIR FILTER USING RECTANGULAR WINDOW

clc;close all;clear all;

rp=input('enter the passband ripple');

rs=input('enter the stopband ripple');

fp=input('enter the passband ripple');

fs=input('enter the stopband ripple');

f=input('enter the sampling frequency');

wp=2*fp/f;

ws=2*fs/f;

num=-20*log10(sqrt(rs*rp))-13;

dem=14.6*(fs-fp)/f;

n=ceil(num/dem);

if(rem(n,2)~=0)

n=n1;

n=n-1;

end

y=RECTWIN(n1);

%bandpass filter

wn=[wp ws];

b=fir1(n,wn,y);

[h,o]=freqz(b,1,256);

m=20*log10*(abs(h));

an=angle(h);

subplot(2,1,1);

plot(o/pi,m);

xlabel('normalised freq-->');

ylabel('gain in db-->');

subplot(2,1,2);

plot(0/pi,an);

xlabel('normalised freq-->');

ylabel('phase in radians-->');

10. FIR FILTER USING HAMMING WINDOW

clc; clear all; close all

rp=input('enter the passband ripple');

rs=input('enter the stopband ripple');

fp=input('enter the passband freq');

fs=input('enter the stopband freq');

f=input('enter the sampling freq');

wp=2*fp/f;ws=2*fs/f;

num=-20*log10(sqrt(rp*rs))-13;

dem=14.6*(fs-fp)/f;

n=ceil(num/dem);

n1=n+1;

if(rem(n,2)~=0);

n1=n;

n=n-1;

end

y=hamming(n1);

%LOW -PASS FILTER

b=fir1(n,wp,y);

[h,o]=freqz(b,1,256);

m=20*log10(abs(h));

subplot(2,2,1);plot(o/pi,m);


xlabel('(a)normalised frequency-->');

title('LOW-PASS FILTER');

%BAND PASS FILTER

wn=[wp ws];

b=fir1(n,wn,y);

[h,o]=freqz(b,1,256);

m=20*log10(abs(h));

subplot(2,2,3);plot(o/pi,m);


xlabel('(c)normalised frequency-->');

title('BAND PASS FILTER');

11. CIRCULAR CONVOLUTION

clc;

clear all;

close all;

g=input('1 sequence');

h=input('2 sequence');

N1=length(g);

N2=length(h);

N=max(N1,N2);

N3=N1-N2;

if(N3>=0)

h=[h,zeros(1,N3)];

else

g=[g,zeros(1,-N3)];

end

for n=1:N

y(n)=0;

for i=1:N

j=n-i+1;

if(j<=0)

j=N+j;

end

end

y(n)=[y(n)+g(i)*h(j)];

stem(y)

end

12. IIR FILTER DESIGN

clc;

close all;

clear all;

rp=input('enter the pass band ripple');

rs=input('enter the stop band ripple');

wp=input('enter the pass band freq');

ws=input('enter the stop band freq');

fs=input('enter the sampling feq');

w1=2*wp/fs;

w2=2*ws/fs;

[h,wn]=buttord(w1,w2,rp,rs);

[b,a]=butter(h,wn);

w=0:.01:pi;

[h,om]=freqz(b,a,w);

m=20*log10(abs(h));

an=angle(h);

subplot(2,1,1);

plot(om/pi,m);

ylabel('gain in db....>');

xlabel('(a) normalised frequency>');

subplot(2,1,2);

plot(om/pi,an);

xlabel('(b) normalised frequency');

ylabel('phase in radian');

DSP PROGRAMS

1. Sine Waveform generation

;Starting address :1000h

;Output address (DSPIK) : 2000h

.include "5416_iv.asm"

.def start

.data

con1 .word 0555h ;1/3!

con2 .word 0044h ;1/5!

con3 .word 0001h ;1/7!

con4 .word 0fffh ;1/2!

con5 .word 0155h ;1/4!

con6 .word 000bh ;1/6!

fs .word 7d00h

fm .word 07cfh

pi .word 0c8ch

ms .word 0

mx .word 0

CNT .word 256

.text

start LD #con1,DP

RSBX INTM

LD #022Bh,0,A

STLM A,PMST

;------------------------Serial Port Initializations-------------------------

;--------------------------McBSP0 Initializations----------------------------

SSBX INTM

STM SPCR1,McBSP0_SPSA ;SPCR1 reset

STM #0090h,McBSP0_SPSD

NOP

NOP



STM PCR,McBSP0_SPSA ;PCR

STM #0A00h,McBSP0_SPSD

STM RCR1,McBSP0_SPSA ;RCR1

STM #00A0h,McBSP0_SPSD ;32 BITS WORDSIZE



STM XCR1,McBSP0_SPSA ;XCR1




STM SRGR1,McBSP0_SPSA ;SRGR1

STM #000Bh,McBSP0_SPSD ;--17


STM #303Fh,McBSP0_SPSD

STM MCR1,McBSP0_SPSA ;MCR1




STM RCERB,McBSP0_SPSA ;RCERB


STM RCERA,McBSP0_SPSA ;RCERA


STM XCERB,McBSP0_SPSA ;XCERB


STM XCERA,McBSP0_SPSA ;XCERA


STM SPCR1,McBSP0_SPSA

STM #0091h,McBSP0_SPSD ;Take 'em out of reset

NOP

NOP



;--------------------------McBSP1 Initializations------------------------------



NOP

NOP














STM #0002h,McBSP1_SPSD ;--5


STM #303Bh,McBSP1_SPSD















NOP

NOP



;--------------------End of Serial Ports Initializations-----------------------

RSBX INTM

LD #02Fh,0,A

STLM A,IMR

STM #0h,McBSP0_DXR1

STM #0h,McBSP0_DXR2

STM #0007h,GPIOCR

STM #0003h,GPIOSR

STM #SPCR2,McBSP1_SPSA

STM #00E1h,McBSP1_SPSD ;Mclk

NOP

STM #0007h,GPIOSR


STM #00E1h,McBSP0_SPSD ;Sclk & Fs

;----------------------------------------------------------------------------

STM #256,BK

STM #2000h,AR5

SSBX SXM

WAIT NOP

NOP

LD CNT,A

BC WAVE,AEQ

NOP

B WAIT

_XINT0_ISR

LD *AR5+%,A

STLM A,McBSP0_DXR1 ;o/p for R Channel

STLM A,McBSP0_DXR2 ;o/p for L Channel

LD CNT,A

SUB #1,A

STL A,CNT

RETE

WAVE LD #0,A

STLM A,IMR

LD #con1,DP

STM #1508h,AR2

LD fm,T

MPY *AR2,A

STM #1506h,AR2

RPT #15

SUBC *AR2,A

STL A,ms

;COSINE APPROX

LD ms,T ;X

STM #1509h,AR2

MPY *AR2+,A

SFTA A,-5

STL A,*AR2 ;X^2

STM #150Ah,AR2

MPY *AR2+,A ;X^3

SFTA A,-9

STL A,*AR2

STM #150Bh,AR2

MPY *AR2+,A ;X^4

SFTA A,-9

STL A,*AR2

STM #150Ch,AR2

MPY *AR2+,A ;X^5

SFTA A,-9

STL A,*AR2

STM #150Dh,AR2

MPY *AR2+,A ;X^6

SFTA A,-9

STL A,*AR2

STM #150Eh,AR2

MPY *AR2+,A ;X^7

SFTA A,-9

STL A,*AR2

;cos x = 1 - x ^2 / 2! + x^4 / 4! - x^6 / 6! + ....

STM #150Ah,AR2

LD con4,T

MPY *AR2,A

SFTA A,-13

LD #1FFFh,B

SUB A,B

STM #150ch,AR2

LD con5,T

MPY *AR2,A

SFTA A,-13

ADD A,B

STM #150eh,AR2

LD con6,T

MPY *AR2,A

SFTA A,-13

SUB A,B

STM #1600h,AR1

STL B,*AR1+

LD #0,A

RPT #1

STL A,*AR1+

;sin x = x - x ^3 / 3! + x^5 / 5! - x^7 / 7! + ....

STM #150Bh,AR2

LD con1,T

MPY *AR2,A

SFTA A,-13

STM #1509h,AR2

LD *AR2,4,B

SUB A,B

STM #150Dh,AR2

LD con2,T

MPY *AR2,A

SFTA A,-13

ADD A,B

STM #150Fh,AR2

LD con3,T

MPY *AR2,A

SFTA A,-13

SUB A,B

STL B,*AR1

;WAVE GENERATION

STM #2000h,AR7

STM #256,BRC

RPTB wave1

STM #1602h,AR2

STM #1600h,AR3

MPY *AR2,*AR3,A

SFTA A,-12

STM #1602h,AR4

STM #1601h,AR5

MVDD *AR4,*AR5

STM #1603h,AR6

LD *AR6,B

SUB B,A

STL A,*AR7+

STM #1602h,AR6

STL A,*AR6

STM #1601h,AR4

STM #1603h,AR5

MVDD *AR4,*AR5

NOP

wave1 NOP

STM #2000h,AR5

NOP

NOP

LD #256,A

STL A,CNT

NOP

NOP

LD #02Fh,0,A

STLM A,IMR

NOP

NOP

B WAIT

2. Square wave generation

;Starting address : 1000h

;Output address :2000h


.def start

.data

POS .word 30 ;Positive Count value

NEG .word 30 ;Negative Count Value

P .word 0 ;Dummy 1

N .word 0 ;Dummy 2

.word 07fffh,08001h ;Maximum Positive and Negative Values

CNT .word 128 ;Total No.of Samples

E .word 45h ;Display Character 'E'

.text

start LD #POS,DP

; Data Page Pointer

RSBX INTM

LD #022Bh,0,A

STLM A,PMST



SSBX INTM



NOP

NOP































NOP

NOP






NOP

NOP































NOP

NOP




RSBX INTM

LD #027h,0,A

STLM A,IMR

STM #0h,McBSP0_DXR1

STM #0h,McBSP0_DXR2

STM #0007h,GPIOCR

STM #0003h,GPIOSR



NOP

STM #0007h,GPIOSR



;----------------------------------------------------------------------------

;--------------------------Square Wave Generation Program-------------------

;--------------------------Initialisation-------------------------------------------------------

STM #128,BK

SSBX SXM

STM #1504h,AR2 ;Memory location of 7fffh

STM #1505h,AR3 ;Memory location of 8001h

STM #2000h,AR4 ;Square Wave Output

WAIT NOP

NOP

LD CNT,B

BC WAVE,BEQ ;Jump to WAVE if Count Equals to zero

NOP

B WAIT

_XINT0_ISR

NOP

NOP

LD *AR4+%,A ;Transmitting Square Wave Output to

CODEC

STLM A,McBSP0_DXR1

STLM A,McBSP0_DXR2

LD CNT,B ;Count=Count-1

SUB #1h,B

STL B,CNT

RETE

WAVE LD #128,A ;Initialization of Count Value (CNT)

STL A,CNT

NOP

NOP

PORTW E,0

LD #0h,A ;Disable All the Interrupts (Interrupt Mask Register)

STLM A,IMR

STM #1504h,AR2

STM #1505h,AR3

STM #2000h,AR4

STM #6,BRC

RPTB L1 ;Loop for 128 Samples

LD POS,A

STL A,P

LD NEG,B

STL B,N

L2 LD *AR2,A ;Positive Loop (30 Samples)

STL A,*AR4+

LD P,B

SUB #1h,B

STL B,P

BC L2,BNEQ

L3 LD *AR3,A ;Negative Loop (30 Samples)

STL A,*AR4+

LD N,B

SUB #1,B

STL B,N

BC L3,BNEQ

NOP

L1 NOP

LD #027h,A ;Initialization of Interrupts

STLM A,IMR ;Interrupt Mask Register

STM #2000h,AR4 ;Output Memory

B WAIT ;Branch to Wait Loop

3. FIR application Program ;Filter order 9

;Cutoff Frequency 1KHz

;--------------------------------------------------------------------------------

;Starting address :1000h

;Input address : 1600h

;Output address : 1700h

.include "5416_IV.asm"

.data

COEFF .word 086eh,0b9eh,0e5fh,1064h,1176h,1064h,0e5fh,0b9eh,086eh

;Filter Co-efficients in data ;

memory

.text

start LD #COEFF,DP ;Variable Declaration

RSBX INTM

LD #022Bh,0,A

STLM A,PMST



SSBX INTM



NOP

NOP































NOP

NOP






NOP

NOP































NOP

NOP




RSBX INTM

LD #02Fh,0,A

STLM A,IMR

STM #0h,McBSP0_DXR1

STM #0h,McBSP0_DXR2

STM #0007h,GPIOCR

STM #0003h,GPIOSR



NOP

STM #0007h,GPIOSR



;----------------------------------------------------------------------------

;----------------Program Starts -----------------------------------------

;------------------------Algorithm-------------------------------------

;-----FIR filter needs three buffers for Implementation

;-----One Buffer stores Input samples (128)

;-----Second Buffer is an Temporary buffer (Initially zero) (Size should be equal to the

order of the filter)

;-----Third Buffer Stores the output

;------Implementation-------------------------------------------------

;------First the Input sample from the CODEC is loaded to an accumulator.

;------The accumulator value is loaded to an Input Buffer (1600h Memory Location).

;------Initialize the temporary buffer.

;------Move the first Input sample to the Temporary buffer from Input buffer.

;------Modify the Temporary buffer to point out the last location (In this example the

modifier is 8 which is the order of ;the filter)

;-----Implementation of FIR filter is done by Using MACD Instruction

;-----Finally the output will be in Higher order. So Shift the output by -15.

;-----Store the Lower order value in Output buffer and transmit the output to CODEC.

SSBX SXM

RSBX FRCT

RSBX OVM

STM #150,BK ;Circular Buffer for Input and Output

STM #1600h,AR5 ;Input Buffer Starts at 1600h

STM #1700h,AR6 ;Output Buffer Starts at 1700h

LD #0h,A

STM #1900h,AR3 ;Temporary Buffer Initialization

RPT #10

STL A,*AR3+

STM #1900h,AR3

WAIT NOP

NOP

B WAIT

_XINT0_ISR

LDM McBSP0_DRR1,A ;R Channel (Input Sample From

CODEC)

STL A,0,*AR5 ;Loading Input Sample to an Input Buffer

(1600h)

STM #1900h,AR3 ;Initialization of Temporary Buffer

MVDD *AR5,*AR3 ;Moving Input Sample from Input buffer

to Temporary Buffer

RPT #7 ;Modify Temporary buffer

MAR *AR3+

RPT #8 ;Implementation of FIR Filter

y(n)=x(k)*h(n-k)

MACD *AR3-,COEFF,A

SFTA A,-15 ;Shifting the output to Lower order



STL A,0,*AR6+% ;Output is stored at 1700h

MAR *AR5+% ;Modify the Input Buffer

RETE

4. FIR FILTER DESIGN

;Starting address : 0700h

;Input address :1600h

;Output address :1700h


.def start

.data

bpole .word 97e3h,154fh ;IIR Filter Co-efficients

azero .word 0b4ch,1698h,0b4ch

xin .word 0,0

xout .word 0

yin .word 0

S1 .word 00

E .word 45h

.text

start LD #bpole,DP ;Variable Declaration

RSBX INTM

LD #022Bh,0,A

STLM A,PMST



SSBX INTM



NOP

NOP































NOP

NOP






NOP

NOP































NOP

NOP




RSBX INTM

LD #02Fh,0,A

STLM A,IMR

STM #0h,McBSP0_DXR1

STM #0h,McBSP0_DXR2

STM #0007h,GPIOCR

STM #0003h,GPIOSR



NOP

STM #0007h,GPIOSR



SSBX SXM

RSBX FRCT

RSBX OVM

STM #128,BK ;Circular Buffer for Input and Output

STM #1600h,AR4 ;Input Buffer Starts at 1600h

STM #1700h,AR1 ;Output Buffer Starts at 1700h

STM #1400h,AR5 ;IIR Filter Output

STM #1500h,AR6 ;Zero Output Buffer

WAIT NOP

NOP

NOP

NOP

NOP

B WAIT

_XINT0_ISR

LDM McBSP0_DRR1,A ;R Channel (Input Sample From CODEC)

LDM McBSP0_DRR2,A ;R Channel (Input Sample From CODEC)

STM #1800h,AR3 ;Pole Temporary Buffer

STM #1300h,AR7 ;Pole Output Buffer

STL A,0,xin

NOP

NOP

LD xin,A

STL A,0,*AR4+%

NOP

NOP

STM xout,AR2

RPT #02h ;Multiplication of Input with zeros

MACD *AR2-,azero,A

SFTA A,-15

STL A,0,*AR6 ;Zero Output

MVDD *AR5,*AR3+ ;Transfer IIR Output to Temp Buffer

LD #bpole,DP

RPT #01h

MACD *AR3-,bpole,A ;Multiplication of Output with Poles

SFTA A,-15

STL A,0,*AR7 ;Pole Output

NOP

NOP

LD *AR6,A

LD *AR7,B

SUB B,0,A ;Zero Output - Pole Output

STL A,0,*AR5

STL A,0,*AR1+%



RETE

5. FFT DESIGN

;Starting address: 0700h

;Input address: 1000h

;Output address: 1800h

.include "twi.asm"

.include "twr.asm"

.include "cos.asm"


.def start

.data

R1 .word 0h ;Variables

I1 .word 0h

stages .word 7h

grp .word 64

grp1 .word 0h

but .word 1h

but1 .word 0h

R .word 0h

I .word 0h

A1 .word 0h

sizetw .word 40h

sizein .word 80h

bitr .word 40h

shi .word 7Fh

CNT .word 128

E .word 45h

.text

start LD #R1,DP

RSBX INTM

LD #022Bh,0,A

STLM A,PMST



SSBX INTM



NOP

NOP































NOP

NOP






NOP

NOP































NOP

NOP




RSBX INTM

LD #017h,0,A

STLM A,IMR

STM #0h,McBSP0_DXR1

STM #0h,McBSP0_DXR2

STM #0007h,GPIOCR

STM #0003h,GPIOSR



NOP

STM #0007h,GPIOSR



;----------------------------------------------------------------------------

;-----------------------------Program Starts----------------------

STM #1000h,AR6 ;FFT I/p

STM #1800h,AR1 ;FFT O/p

SSBX SXM

RSBX OVM

LD #0h,0,A

RPT #127

STL A,*AR1+

STM #1800h,AR1

STM #3500h,AR7

WAIT NOP

NOP

LD CNT,B

BC FFT,BEQ

NOP

NOP

B WAIT

_RINT0_ISR

PSHM AL

PSHM AH

PSHM AG

PSHM BL

PSHM BH

PSHM BG

LD *AR6+,0,A



LD CNT,B

SUB #1h,0,B

STL B,0,CNT

POPM BG

POPM BH

POPM BL

POPM AG

POPM AH

POPM AL

RETE

FFT NOP

NOP

LD #0,A

STLM A,IMR

STM #1000h,AR6

STM #1800h,AR1

STM #2000h,AR4

STM #1000h,AR3

RPT #127

MVDD *AR4+,*AR3+

LD #R1,DP

NOP

LD #80h,A

STL A,CNT

NOP

PORTW E,0

;------------Bit Reversal-----------------------

;------------For 128 pt FFT The Index value is 128/2=64(40H)----------------

---

STM #0040h,AR0 ;Index

STM #2400h,AR4 ;Bit reversed o/p

NOP

NOP

RPT #127

MVPD #2000h,*AR4+0B ;Bit Reversal

NOP

NOP

STM #2400h,AR5

LD #0h,0,A

STM #2800h,AR3

RPT #127

STL A,0,*AR3+

STM #3000h,AR3 ;TWIDDLE REAL

STM #3400h,AR4 ;TWIDDLE IMAG

STM #40h,BK

;--------------------------Butterfly Loop Begins------------------------------------

SU LD stages,0,A

LD grp,0,B

STL B,grp1

LD but,0,A

STM #2400h,AR5

STM #2800h,AR2

GU LD #40h,B

STLM B,BK

LD but,0,A

STL A,but1

LD #0h,0,B

SUB A,0,B

STL B,A1

STM #3000h,AR3

STM #3400h,AR4

BU LD #80h,B

STLM B,BK

LD *AR5,0,A

LD *AR2,0,B

STL A,0,R

STL B,0,I

LD but,0,A

STLM A,AR0

NOP

NOP

MAR *AR5+0%

MAR *AR2+0%

MPY *AR3,*AR5,A

MPY *AR4,*AR2,B

SUB B,0,A

STH A,R1

MPY *AR3,*AR2,A

MPY *AR4,*AR5,B

ADD A,0,B

STH B,I1

LD R,-1,A

LD R1,0,B

SUB B,0,A

STL A,*AR5

LD I,-1,A

LD I1,0,B

SUB B,0,A

STL A,*AR2

NOP

NOP

NOP

LD A1,0,B

STLM B,AR0

NOP

NOP

MAR *AR5+0%

MAR *AR2+0%

LD R,-1,A

LD R1,0,B

ADD B,0,A

STL A,*AR5+

LD I,-1,A

LD I1,0,B

ADD B,0,A

STL A,*AR2+ ;BUT

NOP

LD #40h,0,B

STLM B,BK

LD grp,0,A

STLM A,AR0

NOP

NOP

NOP

NOP

MAR *AR3+0%

MAR *AR4+0%

LD but1,0,B

SUB #1h,0,B

STL B,0,but1

BC BU,BNEQ ;;;;;Butterfly End

LD #80h,B

STLM B,BK

NOP

NOP

NOP

LD but,0,B

STLM B,AR0

NOP

NOP

MAR *AR5+0%

MAR *AR2+0%

LD grp1,0,B

SUB #1h,0,B

STL B,grp1

BC GU,BNEQ ;;;;;;;;Group End

NOP

LD but,0,B

SFTA B,1

STL B,but

STL B,but1

LD grp,0,B

SFTA B,-1

STL B,grp

STL B,grp1

LD stages,0,A

SUB #1h,0,A

STL A,stages

BC SU,ANEQ ;;;;;;;;;STAGES

LD #0h,0,A

LD #0h,0,B

;-------------------Initialization of Variables-----------------------

LD #7h,0,B

STL B,stages

LD #40h,0,A

STL A,grp

LD #1h,0,B

STL B,but

STM #2400h,AR3

STM #1800h,AR6

STM #7Fh,BRC

RPTB VE

LD *AR3+,A

ABS A

STL A,*AR6+

NOP

VE NOP

NOP

STM #1800h,AR6

LD #0017h,A

STLM A,IMR

NOP

NOP

B WAIT

6. FSK DESIGN

;PROGRAM STARTING ADDRESS 001000

;GRAPH STARTING ADDRESS 001700

;This program is to generate a sine wave from a look-up-table

;There are 16 sine wave samples that represent the 360 degrees of the sine wave starting

from S1


.data

CNT .word 40h

VAR .word 0h

VAR2 .word 0h

.include "1000.asm"

.include "2000.asm"

.text

start

RSBX INTM

LD #022Bh,0,A

STLM A,PMST



SSBX INTM



NOP

NOP































NOP

NOP






NOP

NOP































NOP

NOP




RSBX INTM

LD #02Fh,0,A

STLM A,IMR

STM #0h,McBSP0_DXR1

STM #0h,McBSP0_DXR2

STM #0007h,GPIOCR

STM #0003h,GPIOSR



NOP

STM #0007h,GPIOSR



;----------------------------------------------------------------------------

STM #64,BK

STM #1700h,AR6

STM #1650h,AR7

LD #0h,A

RPT #1000h

STL A,*AR7+

STM #1650h,AR7

WAIT NOP

NOP

NOP

LD CNT,A

BC FSK,AEQ

NOP

NOP

B WAIT

_XINT0_ISR

LDM McBSP0_DRR1,A ;R Channel

LDM McBSP0_DRR2,A ;L Channel

PORTR 0h,VAR

LD *AR6+%,A

STLM A,McBSP0_DXR1 ;o/p for R Channel ;current(Y)

STLM A,McBSP0_DXR2 ;o/p for L Channel ;voltage(R)

LD CNT,A

SUB #1h,A

STL A,CNT

RETE

FSK LD #40h,A

STL A,CNT

STM #1650h,AR1

STM #1700h,AR2 ;OUTPUT

STM #1600h,AR3 ;1000Hz

STM #1610h,AR4 ;2000Hz

LD VAR,A

AND #00FFh,A

NOP

NOP

STL A,VAR

STL A,VAR2

LD #8h,B;

HAI SUB #1h,B;

LD VAR2,A

AND #0001h,A

STL A,*AR1+

LD VAR2,B

SFTA B,-1

STL B,VAR2

BC HAI,BNEQ;

;--------------------------------------------------------------------------------------------------------

STM #1650h,AR1

STM #1700h,AR2 ;OUTPUT

STM #1658h,AR5

LD #8h,B

L5 LD *AR1+,A

BC ZERO,AEQ

ONE STM #1600h,AR3

RPT #7

MVDD *AR3+,*AR2+

B STAT

ZERO STM #1610h,AR4

RPT #7

MVDD *AR4+,*AR2+

STAT SUB #1h,B

BC L5,BGT

PORTW VAR,0h

B WAIT

Documents

EC2306-DSP