audio.c

基于TMS320VC5509的PCM编码

//  测试时音频插孔J5接音源，J7接扬声器。
#include "5509.h"
#include "util.h"

void wait( unsigned int cycles );
void EnableAPLL( );
void main()
{
    SDRAM_init();
    EnableAPLL();
    PLL_Init(144);
    AIC23_Init();
    for(;;)
    {
        AIC23_Mixer();
    }

}

void wait( unsigned int cycles )
{
    int i;
    for ( i = 0 ; i < cycles ; i++ ){ }
}

void EnableAPLL( )
{
    /* Enusre DPLL is running */
    *( ioport volatile unsigned short* )0x1f00 = 4;

    wait( 25 );

    *( ioport volatile unsigned short* )0x1f00 = 0;

    // MULITPLY
    *( ioport volatile unsigned short* )0x1f00 = 0x3000;

    // COUNT
    *( ioport volatile unsigned short* )0x1f00 |= 0x4F8;

    wait( 25 );

    //*( ioport volatile unsigned short* )0x1f00 |= 0x800

    // MODE
    *( ioport volatile unsigned short* )0x1f00 |= 2;

    wait( 30000 );

    // APLL Select
    *( ioport volatile unsigned short* )0x1e80 = 1;

    // DELAY
    wait( 60000 );
}