void main()
{
//initialize intermediary values to zero
for(n = 0; n < 11; n++)
{
w[n] = 0;
}
DSK6713_init(); // Initialize the board support library, must be called first
hCodec = DSK6713_AIC23_openCodec(0, &config); // open codec and get handle
// Configure buffered serial ports for 32 bit operation
// This allows transfer of both right and left channels in one read/write
MCBSP_FSETS(SPCR1, RINTM, FRM);
MCBSP_FSETS(SPCR1, XINTM, FRM);
MCBSP_FSETS(RCR1, RWDLEN1, 32BIT);
MCBSP_FSETS(XCR1, XWDLEN1, 32BIT);
// set codec sampling frequency
DSK6713_AIC23_setFreq(hCodec, DSK6713_AIC23_FREQ_16KHZ);
// interrupt setup
IRQ_globalDisable(); // Globally disables interrupts
IRQ_nmiEnable(); // Enables the NMI interrupt
IRQ_map(IRQ_EVT_RINT1,15); // Maps an event to a physical interrupt
IRQ_enable(IRQ_EVT_RINT1); // Enables the event
IRQ_globalEnable(); // Globally enables interrupts
while(1) // main loop - do nothing but wait for interrupts
{
}
}
void main()
{
DSK6713_init(); // Initialize the board support library, must be called first
hCodec = DSK6713_AIC23_openCodec(0, &config); // open codec and get handle
//convert coefficients to Q15 format
short i,j;
for(i = 0; i < 33; i++)
{
w[i] = 0;
}
for(i = 0; i < 11; i++)
{
for(j = 0; j < 3; j++)
{
NUM_s[i][j] = NUM[i][j] << 5;
DEN_s[i][j] = DEN[i][j] << 5;
}
}
// Configure buffered serial ports for 32 bit operation
// This allows transfer of both right and left channels in one read/write
MCBSP_FSETS(SPCR1, RINTM, FRM);
MCBSP_FSETS(SPCR1, XINTM, FRM);
MCBSP_FSETS(RCR1, RWDLEN1, 32BIT);
MCBSP_FSETS(XCR1, XWDLEN1, 32BIT);
// set codec sampling frequency
DSK6713_AIC23_setFreq(hCodec, DSK6713_AIC23_FREQ_16KHZ);
// interrupt setup
IRQ_globalDisable(); // Globally disables interrupts
IRQ_nmiEnable(); // Enables the NMI interrupt
IRQ_map(IRQ_EVT_RINT1,15); // Maps an event to a physical interrupt
IRQ_enable(IRQ_EVT_RINT1); // Enables the event
IRQ_globalEnable(); // Globally enables interrupts
while(1) // main loop - do nothing but wait for interrupts
{
}
}
/********************************** init_hardware() **********************************/
void init_hardware()
{
// Initialize the board support library, must be called first
DSK6713_init();
// Start the AIC23 codec using the settings defined above in config
H_Codec = DSK6713_AIC23_openCodec(0, &Config);
/* Function below sets the number of bits in word used by MSBSP (serial port) for
receives from AIC23 (audio port). We are using a 32 bit packet containing two
16 bit numbers hence 32BIT is set for receive */
MCBSP_FSETS(RCR1, RWDLEN1, 32BIT);
/* Configures interrupt to activate on each consecutive available 32 bits
from Audio port hence an interrupt is generated for each L & R sample pair */
MCBSP_FSETS(SPCR1, RINTM, FRM);
/* These commands do the same thing as above but applied to data transfers to
the audio port */
MCBSP_FSETS(XCR1, XWDLEN1, 32BIT);
MCBSP_FSETS(SPCR1, XINTM, FRM);
}
/******************************* init_hardware() ************************************/
void init_hardware()
{
// Initialize the board support library, must be called first
DSK6713_init();
// Start the codec using the settings defined above in config
H_Codec = DSK6713_AIC23_openCodec(0, &Config);
/* Defines number of bits in word used by MSBSP for communications with AIC23
NOTE: this must match the bit resolution set in in the AIC23 */
MCBSP_FSETS(XCR1, XWDLEN1, 32BIT);
/* Set the sampling frequency of the audio port. Must only be set to a supported
frequency (8000/16000/24000/32000/44100/48000/96000) */
DSK6713_AIC23_setFreq(H_Codec, get_sampling_handle(&sampling_freq));
}
void main()
{
// initialize the save buffers
for(j = 0; j < 2; j++){
for (i=0;i<SAVES;i++) {
cde_save[i] = 0;
pcf_save[i] = 0;
clockoffset_save[i] = 0.0;
fde_save[i] = 0.0;
imax_save[i] = 0;
recbuf_start_clock_save[i] = 0;
ppm_estimate_save[i] = 0.0;
ytilde_save[i] = 0.0;
state_prediction[j][i] = 0.0;
state_estimate[j][i] = 0.0;
}
}
// set up the fractionally shifted buffers
for(k = 0; k < FER; k++){
fractionalShift = ((double) k )/((double) FER); // number of samples to shift
for (i=-N;i<=N;i++){
x = ((double) i - fractionalShift)*BW;
if (x==0.0) {
y = 32767.0;
}
else
{
t = ((double) i - fractionalShift)*CBW;
y = 32767.0*cos(2*PI*t)*sin(PI*x)/(PI*x); // double
}
j = i;
if (j<0) {
j += L; // wrap
}
allMyDelayedWaveforms[k][j] = (short) y;
}
}
// set up the cosine and sin matched filters for searching
// also initialize searching buffer
for (i=0;i<M;i++){
t = i*CBW; // time
y = cos(2*PI*t); // cosine matched filter (double)
mfc[i] = (float) y; // cast and store
y = sin(2*PI*t); // sine matched filter (double)
mfs[i] = (float) y; // cast and store
buf[i] = 0; // clear searching buffer
}
// initialize clock buffers
for (i=0;i<L;i++) {
clockbuf[i] = 0;
clockbuf_shifted[0][i] = 0;
clockbuf_shifted[1][i] = 0;
}
// initialize sinc pulse buffer
for (i=0;i<LL;i++)
sincpulsebuf[i] = 0;
// set up clock buffer and sinc pulse buffer
// to play modulated sinc centered at zero
for (i=-N;i<=N;i++){
x = i*BW;
if (i!=0) {
t = i*CBW;
y = 32767.0*cos(2*PI*t)*sin(PI*x)/(PI*x); // double
}
else {
y = 32767.0;
}
j = i;
if (j<0) {
j += L; // wrap
}
clockbuf[j] = (short) y;
j = i;
if (j<0) {
j += LL; // wrap
}
sincpulsebuf[j] = (short) y;
}
// set up inphase and quadrature sinc pulses for coarse and fine delay estimators
j = 0;
for (i=-N;i<=N;i++){
x = i*BW;
if (i!=0) {
t = i*CBW;
si[j] = (float) (cos(2*PI*t)*sin(PI*x)/(PI*x));
sq[j] = (float) (sin(2*PI*t)*sin(PI*x)/(PI*x));
}
else {
si[j] = 1.0;
sq[j] = 0.0;
}
j++;
}
DSK6713_init(); // Initialize the board support library, must be called first
DSK6713_LED_init(); // initialize LEDs
hCodec = DSK6713_AIC23_openCodec(0, &config); // open codec and get handle
// Configure buffered serial ports for 32 bit operation
// This allows transfer of both right and left channels in one read/write
MCBSP_FSETS(SPCR1, RINTM, FRM);
MCBSP_FSETS(SPCR1, XINTM, FRM);
MCBSP_FSETS(RCR1, RWDLEN1, 32BIT);
MCBSP_FSETS(XCR1, XWDLEN1, 32BIT);
// set codec sampling frequency
DSK6713_AIC23_setFreq(hCodec, DSK6713_AIC23_FREQ_8KHZ);
// interrupt setup
IRQ_globalDisable(); // Globally disables interrupts
IRQ_nmiEnable(); // Enables the NMI interrupt
IRQ_map(IRQ_EVT_RINT1,15); // Maps an event to a physical interrupt
IRQ_enable(IRQ_EVT_RINT1); // Enables the event
IRQ_globalEnable(); // Globally enables interrupts
DSK6713_LED_toggle(3);
while(1) // main loop
{
if ((state==2)&&(delay_est_done==0)){ // TIME TO COMPUTE DELAY ESTIMATES
DSK6713_LED_toggle(1); // toggle LED here for diagnostics
/*****************
* *
* ESTIMATION *
* *
****************/
// compute coarse delay estimate
zmax = 0.0; // maximum
imax = 0; // index of maximum
for (i=0;i<(2*M-1);i++){ // lag index
z = 0;
for (j=0;j<(2*N+1);j++) {
z+= si[j]*recbuf[i+j]; // correlation at lag i
}
if (abs(z)>zmax) {
zmax = abs(z); // store maximum
imax = i; // store index of maximum
}
}
cde = recbuf_start_clock + imax + N; // coarse delay estimate (DRB: +N here because si is already shifted by N)
// cde is the number of samples elapsed since we launched the S->M sinc pulse
// compute fine delay estimate
zi = 0.0; // in phase
zq = 0.0; // quadrature
for (j=0;j<(2*N+1);j++) {
zi+= si[j]*recbuf[imax+j]; // correlation at lag imax
zq+= sq[j]*recbuf[imax+j]; // correlation at lag imax
}
pcf = atan2(zq,zi)*(2*INVPI); // assumes wc = pi/2
fde = (float) cde + pcf;
// compute actual clock offset
// the value computed here is always non-negative and
// represents the number of samples the master clock is ahead of the slave clock
// (or the number of samples the slave clock is behind the master clock)
// S->M sinc pulse was launched at time 0
// M->S sinc pulse was received at time fde (should be positive)
// to synchronize, we want slave clock ticks to appear at fde/2 + k*L for k=0,1,....
clockoffset = fde*0.5;
// testing/debugging
imax_save[save_index] = imax;
recbuf_start_clock_save[save_index] = recbuf_start_clock;
cde_save[save_index] = cde;
pcf_save[save_index] = pcf;
fde_save[save_index] = fde;
clockoffset_save[save_index] = clockoffset;
//If first time running
if(!hasSaved && save_index == 0){
state_estimate[0][0] = clockoffset* TS;
state_estimate[1][0] = 0;
state_prediction[0][1] = clockoffset * TS;
state_prediction[1][1] = 0;
}
else
{ // save_index > 0
ytilde = clockoffset * TS - state_prediction[0][save_index]; // innovation (difference between current observation and prediction)
state_estimate[0][save_index] = state_prediction[0][save_index] + ((double) K1)*ytilde; // filtered clock offset estimate
state_estimate[1][save_index] = state_prediction[1][save_index] + ((double)K2)*ytilde; // filtered frequency offset estimate
//Determine if a glitch has happened
if (save_index+1<SAVES) {
// generate predictions for next observation (make sure multiplication by LL doesn't cause datatype problems)
state_prediction[0][save_index+1] = state_estimate[0][save_index] + state_estimate[1][save_index] * (double)T0;//* LL;
state_prediction[1][save_index+1] = state_estimate[1][save_index];
}
else if(save_index + 1 == SAVES){
state_prediction[0][0] = state_estimate[0][save_index] + state_estimate[1][save_index]* (double)T0;//* LL;
state_prediction[1][0] = state_prediction[1][save_index];
}
}
//Calculate the rate offset
if(!hasSaved && save_index < 1){
if(save_index == 0)
rateoffset_estimate = 0;
else
rateoffset_estimate = TS * (clockoffset_save[save_index] - clockoffset_save[save_index - 1]);
}
//Otherwise, use kalman filter
else{
rateoffset_estimate = state_prediction[0][save_index] - state_estimate[0][save_index];
}
//
if(clockoffset_save[save_index] > L && clockoffset_save[save_index - 1] < L)
adjustedclockoffset = clockoffset_save[save_index] + 5 * L * rateoffset_estimate;
else if(clockoffset_save[save_index] > L && clockoffset_save[save_index - 1] < L)
adjustedclockoffset = clockoffset_save[save_index] + 3 * L *rateoffset_estimate;
else
adjustedclockoffset = clockoffset_save[save_index] + 4 * L * rateoffset_estimate;
////////
j = (short) adjustedclockoffset; // casting from float to short just truncates, e.g., 3.99 becomes 3
fractionalShift = adjustedclockoffset - (double) j; // fractionalShift >= 0 and < 1 tells us how much of a sample is left
k = (short) (fractionalShift * (double) FER + 0.5); // this now rounds and givse results on 0,...,FER
if (k==FER) { // we rounded up to the next whole sample
k = 0;
j++;
}
for (i=0;i<L;i++) {
ell = j+i;
while (ell>=L) {
ell = ell-L;
}
if (current_clockbuf==0) {
clockbuf_shifted[1][ell] = allMyDelayedWaveforms[k][i]; // write other buffer
}
else {
clockbuf_shifted[0][ell] = allMyDelayedWaveforms[k][i]; // write other buffer
}
}
// when can we swap buffers?
buffer_swap_index = j+L/2; // midpoint of the silent part (I think)
while (buffer_swap_index>=L)
buffer_swap_index = buffer_swap_index-L;
// tell the ISR the calculations are done
delay_est_done = 1;
// update save index
save_index++;
if (save_index>=SAVES) // wrap
{
save_index = 0;
hasSaved = 1;
}
DSK6713_LED_toggle(1); // toggle LED here for diagnostics
}
else if (buffer_just_swapped==1) {
// this code computes the next buffer and attempts to corect for the frequency offset
buffer_just_swapped = 0;
// copy appropriate fractionally shifted clock buffer to shifted clock buffer
adjustedclockoffset = adjustedclockoffset + ((double) L)*one_over_beta; // adjust latency of next pulse
while (adjustedclockoffset>((double) L))
adjustedclockoffset = adjustedclockoffset - (double) L;
j = (short) adjustedclockoffset; // casting from float to short just truncates, e.g., 3.99 becomes 3
fractionalShift = adjustedclockoffset - (double) j; // fractionalShift >= 0 and < 1 tells us how much of a sample is left
k = (short) (fractionalShift * (double) FER); // this also truncates and should give result on 0,...,FER-1
for (i=0;i<L;i++) {
ell = j+i;
if (ell>=L) {
ell = ell-L;
}
if (current_clockbuf==0) {
clockbuf_shifted[1][ell] = allMyDelayedWaveforms[k][i]; // write other buffer
}
else {
clockbuf_shifted[0][ell] = allMyDelayedWaveforms[k][i]; // write other buffer
}
}
} // if ((state==2)&&(delay_est_done==0))
} // while(1)
} // void main
void main()
{
DSK6713_init(); // Initialize the board support library, must be called first
hCodec = DSK6713_AIC23_openCodec(0, &config); // open codec and get handle
// Configure buffered serial ports for 32 bit operation
// This allows transfer of both right and left channels in one read/write
MCBSP_FSETS(SPCR1, RINTM, FRM);
MCBSP_FSETS(SPCR1, XINTM, FRM);
MCBSP_FSETS(RCR1, RWDLEN1, 32BIT);
MCBSP_FSETS(XCR1, XWDLEN1, 32BIT);
// set codec sampling frequency
DSK6713_AIC23_setFreq(hCodec, DSK6713_AIC23_FREQ_8KHZ);
//initialize buffers to zero
init();
// interrupt setup
IRQ_globalDisable(); // Globally disables interrupts
IRQ_nmiEnable(); // Enables the NMI interrupt
IRQ_map(IRQ_EVT_RINT1,15); // Maps an event to a physical interrupt
IRQ_enable(IRQ_EVT_RINT1); // Enables the event
IRQ_globalEnable(); // Globally enables interrupts
//temporary variable for real-imag swapping for ifft, placed here for convenience
float temp = 0;
while(1) // main loop - do nothing but wait for interrupts
{
if(pingFlag == 1){
for(n = 0; n < FFT_LENGTH; n++){
if(n < (ORDER - 1)){
pingU[n] = Z[n];
}
else{
pingU[n] = PING[n - (ORDER - 1)];
}
}
// cfftr2_dit(pingU,w,FFT_LENGTH); //TI floating-pt complex FFT
// bitrev(pingU,ix,FFT_LENGTH); //freq scrambled->bit-reverse X
for(n = 0; n < FFT_LENGTH; n++){
// V[n] = cmplxMult(h[n],pingU[n]);
V[n] = pingU[n];
//swap real and imaginary for ifft, remember to uncomment temp as well
// temp = V[n].re;
// V[n].re = V[n].im;
// V[n].im = temp;
}
// cfftr2_dit(V,w,FFT_LENGTH) ; //TI floating-pt complex ifft
// bitrev(V,ix,FFT_LENGTH); //freq scrambled->bit-reverse X
for(n = ORDER - 1; n < FFT_LENGTH; n++)
{
outputPING[n] = V[n].re * 32768;
}
for(n = (FFT_LENGTH - (ORDER - 1)) - (ORDER -1); n < FFT_LENGTH - (ORDER - 1); n++)
{
Z[n] = PING[n];
}
lflag = 1;
}
if(pongFlag == 1){
for(n = 0; n < FFT_LENGTH; n++){
if(n < (ORDER - 1)){
pongU[n] = Z[n];
}
else{
pongU[n] = PONG[n - (ORDER - 1)];
}
}
// cfftr2_dit(pongU,w,FFT_LENGTH) ; //TI floating-pt complex FFT
// bitrev(pongU,ix,FFT_LENGTH); //freq scrambled->bit-reverse X
for(n = 0; n < FFT_LENGTH; n++){
// V[n] = cmplxMult(h[n],pongU[n]);
V[n] = pongU[n];
// swap real and imaginary for ifft, remember to uncomment temp as well
// temp = V[n].re;
// V[n].re = V[n].im;
// V[n].im = temp;
}
// cfftr2_dit(V,w,FFT_LENGTH) ; //TI floating-pt complex ifft
// bitrev(V,ix,FFT_LENGTH); //freq scrambled->bit-reverse X
for(n = ORDER - 1; n < FFT_LENGTH; n++)
{
outputPONG[n] = V[n].re * 32768;
}
for(n = (FFT_LENGTH - (ORDER - 1)) - (ORDER -1); n < FFT_LENGTH - (ORDER - 1); n++)
{
Z[n] = PONG[n];
}
lflag = 1;
}
}
}
void main()
{
// set up the cosine and sin matched filters for searching
// also initialize searching buffer
for (i=0;i<M;i++){
t = i*0.25; // time
y = cos(2*PI*t); // cosine matched filter (double)
mfc[i] = (float) y; // cast and store
y = sin(2*PI*t); // sine matched filter (double)
mfs[i] = (float) y; // cast and store
buf[i] = 0.0; // clear searching buffer
fbuf[i] = 0.0;
}
// initialize input buffer
for (i=0;i<BL;i++)
inbuf[i] = 0.0;
// initialize clock buffer
for (i=0;i<L;i++)
clockbuf[i] = 0;
// set up clock buffer to play modulated sinc centered at zero
for (i=-N;i<=N;i++){
x = i*BW;
if (i!=0) {
t = i*0.25;
y = ((double) CLOCKAMPLITUDE)*cos(CARRIERKHZ*PI*t)*sin(PI*x)/(PI*x); // double
}
else {
y = ((double) CLOCKAMPLITUDE);
}
j = i;
if (j<0) {
j += L; // wrap
}
clockbuf[j] = (short) y;
}
DSK6713_init(); // Initialize the board support library, must be called first
DSK6713_LED_init(); // initialize LEDs
hCodec = DSK6713_AIC23_openCodec(0, &config); // open codec and get handle
// Configure buffered serial ports for 32 bit operation
// This allows transfer of both right and left channels in one read/write
MCBSP_FSETS(SPCR1, RINTM, FRM);
MCBSP_FSETS(SPCR1, XINTM, FRM);
MCBSP_FSETS(RCR1, RWDLEN1, 32BIT);
MCBSP_FSETS(XCR1, XWDLEN1, 32BIT);
// set codec sampling frequency
DSK6713_AIC23_setFreq(hCodec, DSK6713_AIC23_FREQ_16KHZ);
// interrupt setup
IRQ_globalDisable(); // Globally disables interrupts
IRQ_nmiEnable(); // Enables the NMI interrupt
IRQ_map(IRQ_EVT_RINT1,15); // Maps an event to a physical interrupt
IRQ_enable(IRQ_EVT_RINT1); // Enables the event
IRQ_globalEnable(); // Globally enables interrupts
while(1) // main loop
{
}
}