I am just a beginner with DSP. And i bought the board TMS320C6713.
I found a simple program from Wiki: http://processors.wiki.ti.com/index.php/File:C6713_audio_minimal.zip
/*
* main.c
*/
#include "dsk6713.h"
#include "dsk6713_aic23.h"
#include "stdlib.h"
#include "math.h"
// Codec configuration settings
DSK6713_AIC23_Config config = { \
0x0017, /* 0 DSK6713_AIC23_LEFTINVOL Left line input channel volume */ \
0x0017, /* 1 DSK6713_AIC23_RIGHTINVOL Right line input channel volume */\
0x01f9, /* 2 DSK6713_AIC23_LEFTHPVOL Left channel headphone volume */ \
0x01f9, /* 3 DSK6713_AIC23_RIGHTHPVOL Right channel headphone volume */ \
0x0011, /* 4 DSK6713_AIC23_ANAPATH Analog audio path control */ \
0x0000, /* 5 DSK6713_AIC23_DIGPATH Digital audio path control */ \
0x0000, /* 6 DSK6713_AIC23_POWERDOWN Power down control */ \
0x0043, /* 7 DSK6713_AIC23_DIGIF Digital audio interface format */ \
0x0001, /* 8 DSK6713_AIC23_SAMPLERATE Sample rate control */ \
0x0001 /* 9 DSK6713_AIC23_DIGACT Digital interface activation */ \
};
void main()
{
DSK6713_AIC23_CodecHandle hCodec;
Int16 OUT_L, OUT_R;
Uint32 IN_L;
// Initialize BSL
DSK6713_init();
//Start codec
hCodec = DSK6713_AIC23_openCodec(0, &config);
// Set frequency to 48KHz
DSK6713_AIC23_setFreq(hCodec, DSK6713_AIC23_FREQ_48KHZ);
for(;;)
{
// Read sample from the left channel
while (!DSK6713_AIC23_read(hCodec, &IN_L));
// Feeding the input directly to output you can add effects here
OUT_L = IN_L;
OUT_R = IN_L;
// Send sample, first left next right channel
while (!DSK6713_AIC23_write(hCodec, OUT_L));
while (!DSK6713_AIC23_write(hCodec, OUT_R));
}
//DSK6713_AIC23_closeCodec(hCodec); // Codec close is unreachable
}
And now i have two questions.
1, what;s the different between while (!DSK6713_AIC23_write(hCodec, OUT_L)); and while (!DSK6713_AIC23_write(hCodec, OUT_R)); If i delete one of them, the output will be the same.
2. If i give the board a constant input (IN_L = 1V). Then i wont get any output. But if i give the board a sine signal.(with Amplitude = 1V and frequency = 1Hz ), then i will got the right output. (output = input). If i check the debug information, i will see the binary of IN_L. But what's the relationship between the binary and my real input value.
Thank you.
