// **********************************************************************************
// *  ADSP-2126x SPORT Internal Loopback Example - DMA Driven Example        *
// *                                                                                *
// *  This example loops back data from tx_buf to rx_buf via SPORT4 to SPORT5       *
// *                                                                                *
// *                                                                                *
// *  Author: Brian M.                                                        *
// *  Analog Devices, Inc.                                                          *
// *  Rev 1.0                                                                       *
// *  7/03                                                                        *
// **********************************************************************************


#define bufsize 10
#include <signal.h>
#include <stdio.h>

// Interrupt Control Bits
#define CBUFEN  0x01000000
#define IRPTEN  0x00001000
#define SP3I    0x00008000
#define SP2IMSK 0x00000800
#define SP2I    0x00000000


// SPORT Control Registers
#define TXSP2A  0x460
#define RXSP3A  0x465
#define TXSP3A  0x464
#define RXSP2A  0x461
#define DIV2    0x402
#define DIV3    0x403
#define SPCTL2  0x400
#define SPCTL3  0x401
#define SPMCTL23 0x404

// SPORT Control Bits
#define SPL     0x00001000
#define SPEN_A  0x00000001
#define SDEN_A  0x00040000
#define SLEN32  0x000001F0
#define SPTRAN  0x02000000
#define IFS     0x00004000
#define FSR     0x00002000
#define ICLK    0x00000400

int tx_buf2a[bufsize]= {0x11111111,
                        0x22222222,
                        0x33333333,
                        0x44444444,
                        0x55555555,
                        0x66666666,
                        0x77777777,
                        0x88888888,
                        0x99999999,
                        0xAAAAAAAA};
int rx_buf3a[bufsize];

/* ISR counters, for debug purposes to see how many times SPORT DMA interrupts are serviced */
int     SP2I_counter = 0;
int     SP3I_counter = 0;

void Count_SPORT3_IRQs(int);

void main()
{
    interrupt(SIG_SP3,Count_SPORT3_IRQs);

/////////////////////////////////////////////////////////////////////////////////////////
//                                                                                     //
//              SPORT Loopback init/test: Use SPORT2 as RX & SPORT3 as TX              //
//                                                                                     //
/////////////////////////////////////////////////////////////////////////////////////////

        // initially clear SPORT control register
        * (volatile int *) SPCTL2 = 0;
        * (volatile int *) SPCTL3 = 0;
        * (volatile int *) SPMCTL23 = 0;

SPORT_DMA_setup:
        /* set internal loopback bit for SPORT2 & SPORT3 */
        * (volatile int *) SPMCTL23 |= SPL;

        /* Configure SPORT2 as a transmitter */
        /* CLKDIV2=[fCCLK(200MHz)/2xFSCLK(20MHz)]-1 = 0x0004 */
        /* FSDIV2=[FSCLK(20 MHz)/TFS(.625 MHz)]-1 = 31 = 0x001F */
        * (volatile int *) DIV2 = 0x001F0004;   //internally generating clock and frame sync
        * (volatile int *)  SPCTL2 = (SPEN_A | SLEN32 | FSR | SPTRAN | IFS | ICLK);

        /* Configure SPORT3 as a receiver */
        * (volatile int *) DIV3 = 0;        /* externally generating clock and frame sync */
        * (volatile int *) SPCTL3 = (SPEN_A | SLEN32 | FSR);
        for(SP2I_counter=0;SP2I_counter<10;SP2I_counter++)
        	* (volatile int *) TXSP2A = tx_buf2a[SP2I_counter%sizeof(tx_buf2a)];

        do
        {}while (SP3I_counter < 10);

        * (volatile int *) SPCTL2 = 0;
        * (volatile int *) SPCTL3 = 0;
        * (volatile int *) SPMCTL23 = 0;        
        
    }
/////////////////////////////////////////////////////////////
//                                                         //
//     SPORT3 Interrupt Service Routines        		   //
//                                                         //
/////////////////////////////////////////////////////////////

void Count_SPORT3_IRQs(int sig_int)
{	
	rx_buf3a[SP3I_counter%sizeof(rx_buf3a)] = * (volatile int *) RXSP3A;
	
	SP3I_counter++;                     /* increment count */
}