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Why is there such a long delay in Talkthru Analog In-Out?

Question asked by bluefrog on Nov 26, 2013
Latest reply on Nov 28, 2013 by bluefrog

I started with the Talktru Analog In-Out example program using an ADZS-21369-EZLITE.  I slightly rewrote the program so I could get data in and out of my program.  When I ran the program I noticed about a 60 sample delay between the input and output.  I assume the example program has the same delay.  I finally reduced my interrupt routine to the program below.  I took a sine wave and split it into RXSP0A and a scope and then took the signal from TXSP1B into the other channel of the scope.  I find about a 1.3ms delay between the two scope waveforms.  Is there someway to configure the SPORT to reduce this?  Do I need to use DMA?  Which manual applies to the 21369, the "2136x SHARC Processor Hardware Reference" manual doesn't include the 21369?

 

Hal

 

 

 

.section /pm seg_pmco;

.global _talkThroughISR;

_talkThroughISR:

       HLoop: r14=r14 XOR r15;

    if EQ JUMP HRight;

   

r10=dm(RXSP0A);          // Read new left sample from ADC

          r13=LSHIFT r10 BY 0x08;

f13=FLOAT r13;

 

 

dm(TXSP1B)=r10; //to scope channel

 

     

rti;

HRight: 

         r10=0;

        

dm(TXSP1B)=r10;

r10=dm(RXSP0A);    //dummy read 

rti;

 

///////////////////////////////////////////////////////////////////////////////////////////////

 

//NAME:     main.asm                                                                         //

//DATE:     7/29/05                                                                          //

//PURPOSE:  ADSP-21369 EZ-KIT Test. Calls initialization routines then waits for interrupts  //

//                                                                                           //

//USAGE:    This file contains the main routine calls functions to set up the talkthrough    //

//          routine. It receives an input signal from the ADC via SPORT0A and outputs to     //

//          DAC's via SPORT1A, SPORT1B, SPORT2A, and SPORT2B.                                //

//                                                                                           //

///////////////////////////////////////////////////////////////////////////////////////////////

 

#include <def21369.h>

#include "btc.h"   //BTC channel to observe variables

.section /pm seg_pmco;

.global _main;

.extern _initPLL;

.extern _initSDRAM;

.extern _initSRU;

.extern _initSPORT;

.extern _init1835viaSPI;

.extern _initMLS;

.extern _initFIR;

_main:

    call _initPLL;        // Initializes PLL for the correct core clock (CCLK) frequency

    call _initSDRAM;      // Initializes SDRAM for the correct SDRAM clock (SDCLK) frequency

 

    call _initSRU;        // Initializes the SRU & DAI/DPI pins

    call _init1835viaSPI; // Initializes the codec

   

    call _initMLS;       //  Initialize MLS sequence generator

   

    call _initFIR;          //  Initialize  FIR  

    call _initSPORT;      // Initializes the transmit and receive serial ports (SPORTS)

   

//-----------------------------------------------------------------

    // Enable interrupts (globally)

    BIT SET MODE1 IRPTEN;

    //----------------------------------------------------------------

    // Unmask the SPORT0 ISR

    LIRPTL = SP0IMSK;

_main.end:

    //----------------------------------------------------------------

    // Loop forever.  Work is driven by interrupts

    jump (pc,0);

 

 

init1835viaSPI.asm

 

#include <def21369.h>

 

#include "ad1835.h"

.global _init1835viaSPI;

//===============================================================

.section/dm seg_dmda;

.var spi_semaphore;

.var config_tx_buf[]=          // Buffer of configuration data

            WR | DACCTRL1 | DACI2S | DAC24BIT | DACFS48,

            WR | DACCTRL2, // e.g.: | DACMUTE_R1 | DACMUTE_L2,

            WR | DACVOL_L1 | DACVOL_MAX,

            WR | DACVOL_R1 | DACVOL_MAX,

            WR | DACVOL_L2 | DACVOL_MAX,

            WR | DACVOL_R2 | DACVOL_MAX,

            WR | DACVOL_L3 | DACVOL_MAX,

            WR | DACVOL_R3 | DACVOL_MAX,

            WR | DACVOL_L4 | DACVOL_MAX,

            WR | DACVOL_R4 | DACVOL_MAX,

            WR | ADCCTRL1 | ADCFS48,

            WR | ADCCTRL2 | ADCI2S | ADC24BIT,

            WR | ADCCTRL3 | IMCLKx2 | PEAKRDEN;

//===============================================================

.section/pm seg_pmco;

_init1835viaSPI:

    //--------------------------

    // Clear SPTFLG and SPICTL regs to start

    r0 = 0;

    dm(SPICTL)=r0;

    dm(SPIFLG)=r0;

    //---------------------------------------------------------

    // Writing TXFLSH and RXFLSH bits in SPICTL clear the SPI

    // transmit and receive FIFOs, respectively.

    r0 = dm(SPICTL);

    r1 = (TXFLSH | RXFLSH );

    r0 = r0 OR r1;

    dm(SPICTL)=r0;

    //----------------------------

    // Setup the baud rate to 500 KHz

    r0 = 100;

    dm(SPIBAUD) = r0;

    //--------------------------------------------

    // Set the SPIFLG register to FLAG3 (0xF708)

    r0 = 0xF708;

    dm(SPIFLG) = r0;

    //------------------------------------------------------

    // Now set the SPI control register

    r0 = (SPIEN |   // enable the port

          SPIMS |   // set SHARC as SPI master

          MSBF |    // send MSB first

          WL16 |    // word length = 16 bits

          TIMOD1);  // Initialize SPI port to begin

                    // transmitting when DMA is enabled

    dm(SPICTL) = r0;

    //-------------------------------------------

    // Set up DAG registers to transmit via SPI

    i4 = config_tx_buf;

    m4 = 1;

    //------------------------------

    // Set up loop to transmit data

    lcntr = LENGTH(config_tx_buf), do word_sent until lce;

        // Send a word

        r0=dm(i4,m4);

        dm(TXSPI)=r0;

        // Wait until "SPI transfer complete" status bit

        //   in SPISTAT (SPIFE) indicates that we can send more

        do checkIfTXisDone until TF;

            ustat3 = dm(SPISTAT);

            BIT TST ustat3 SPIFE;

        checkIfTXisDone:

        nop;

        // Wait an extra 100 cycles to meet the timing

        //   requirements of the AD1835A

        lcntr = 100, do pauseFor1835 until lce;

        pauseFor1835:

        nop;

    word_sent:

    nop;

/*

    //-----------------------------------------

    // Flush SPI buffers after initialization

    //   You may want to do this before sending

    //   other SPI commands to guarantee that

    //   you have not accidentally left data in

    //   the transmit or receive FIFOs.

    r0 = dm(SPICTL);

    r1 = (TXFLSH | RXFLSH );

    r0 = r0 OR r1;

    dm(SPICTL)=r0;

*/

_init1835viaSPI.end:

    rts;

 

 

////////////////////////////////////////////////////////////////////////////////////////////

 

//NAME:     initSPORT.asm

//DATE:     7/29/05

//USAGE:    This file initializes the transmit and receive serial ports (SPORTS). It uses

//               uses SPORT0 to receive data from the ADC and transmits the data to the DAC's

//               via SPORT1A, SPORT1B, SPORT2A and SPORT2B.

//

////////////////////////////////////////////////////////////////////////////////////////////

 

#include <def21369.h>

#include <Main.h>

.global _initSPORT;

.extern H;

.extern HCount;

.extern HiCount;

.extern HirCount;

.extern Mike;

.section/pm seg_pmco;

_initSPORT:

//============================================================

     //

// Make sure that the multichannel mode registers are cleared

//

//============================================================

r0 = 0;

dm(SPMCTL0) = r0;

dm(SPMCTL1) = r0;

dm(SPMCTL2) = r0;

dm(SPCTL0) = r0;

dm(SPCTL1) = r0;

dm(SPCTL2) = r0;

//============================================================

//

// Configure SPORT 0 as a receiver (input from ADC)

//

//    OPMODE = I2S mode

//    SLEN24 = 24 bit of data in each 32-bit word

//    SPEN_A = Enable data channel A

//

//------------------------------------------------------------

r0 = OPMODE | SLEN24 | SPEN_A;

dm(SPCTL0) = r0;

//============================================================

//

// Configure SPORTs 1 & 2 as transmitter (output to DACs 1-4)

//

//    SPTRAN = Transmit on serial port

//    OPMODE = I2S mode

//    SLEN24 = 24 bit of data in each 32-bit word

//    SPEN_A = Enable data channel A

//    SPEN_B = Enable data channel B

//

//------------------------------------------------------------

r0 = SPTRAN | OPMODE | SLEN24 |SPEN_B ;

dm(SPCTL1) = r0;

dm(SPCTL2) = r0;

r14=0xFFFFFFFF;

r15=0xFFFFFFFF;

r3=22;      //initialize  shift of float conversion

r5=0;       //adaptation modes

r1=HCountInit;

dm(HCount)=r1;

b0=Mike;

l0=MikeTaps;

m0=1;

b8=H;

l8=HTaps;

m8=1;

r1=HTaps;

f5=0;

r9=0;       //initial mode

rts;

_initSPORT.end: 

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