DSP例程DA转换程序为什么不用指定GPIO输出？

只看该作者 · 2017-2-20 16:04

看了一个DA的例程，例程里并没有指定DA的输出端口，但是给定了地址。板子上连接到DA芯片输出引脚的插针有DA输出。这是什么原理。是因为数据总线直接访问这个地址，把数据发送到DA芯片的吗？求解.

#include "DSP2833x_Device.h"     // DSP2833x Headerfile Include File

#include "DSP2833x_Examples.h"   // DSP2833x Examples Include File

#include <math.h>



void InitXintf(void);

#define DA_CHA                *(Uint16 *)0x4100

#define DA_CHB                *(Uint16 *)0x4102

#define DA_CHC                *(Uint16 *)0x4104

#define DA_CHD                *(Uint16 *)0x4106

#define DA_TRANS        *(Uint16 *)0x47ff



void main(void)

{

   Uint16 CHA_DATA = 0;

   Uint16 CHB_DATA = 0;

   Uint16 CHC_DATA = 0;

   Uint16 CHD_DATA = 0;

   Uint16 flagA = 0;



   InitSysCtrl();

 

   DINT;





   InitPieCtrl();





   IER = 0x0000;

   IFR = 0x0000;





   InitPieVectTable();

   

   InitXintf();



   while(1)

   {        DA_TRANS = 1;

        if(flagA)

        {

                CHA_DATA -= 100;

                if(CHA_DATA == 0)

        {

                        flagA = 0;

                }

        }

        else

        {

                CHA_DATA += 100;

                if(CHA_DATA == 4000)

                {

                        flagA = 1;

                }

        }



        if(flagA)

                CHB_DATA = 0;

        else

                CHB_DATA = 4000;



        if(CHC_DATA == 4000)

                CHC_DATA = 0;

        else

                CHC_DATA += 100;



        CHD_DATA = 2047 * sin((float)(2 * 3.14 * (float)CHC_DATA / 4000.0)) + 2048;



        DA_CHA = CHA_DATA;//三角波

        DA_CHB = CHB_DATA;//方波

        DA_CHC = CHC_DATA;//锯齿波

        DA_CHD = CHD_DATA;//正弦波

        DA_TRANS = 0;

        DELAY_US(10);



   }

}

只看该作者 · 2017-2-20 16:07

@zhangmangui 求助版主

2万 · 2017-2-20 21:51

598835484 发表于 2017-2-20 16:07
@zhangmangui 求助版主

确定一下    DA是不是接到了CPLD等可编程逻辑单元上
DA是不是接到了类似于XINTF  EMIF等这种总线接口上
如果是DA就是DSP的一个外设    这个外设根据硬件设计会有一个
操作地址（基地址+偏移量）就可以对一个地址操作即操作DA

2万 · 2017-2-20 21:52

看了你的代码那就是Xintf
你看看CPLD的代码吧

只看该作者 · 2017-2-21 22:30

InitXintf怎么定义的？

只看该作者 · 2017-2-21 22:32

设置在InitXintf这个函数里面。

只看该作者 · 2017-2-22 09:32

eefas 发表于 2017-2-21 22:32
设置在InitXintf这个函数里面。

EALLOW;
XintfRegs.XINTCNF2.bit.XTIMCLK = 1;
// No write buffering
XintfRegs.XINTCNF2.bit.WRBUFF = 0;
// XCLKOUT is enabled
XintfRegs.XINTCNF2.bit.CLKOFF = 0;
// XCLKOUT = XTIMCLK/2
XintfRegs.XINTCNF2.bit.CLKMODE = 1;

// Zone 0------------------------------------
// When using ready, ACTIVE must be 1 or greater
// Lead must always be 1 or greater
// Zone write timing
XintfRegs.XTIMING0.bit.XWRLEAD = 3;
XintfRegs.XTIMING0.bit.XWRACTIVE = 7;
XintfRegs.XTIMING0.bit.XWRTRAIL = 3;
// Zone read timing
XintfRegs.XTIMING0.bit.XRDLEAD = 3;
XintfRegs.XTIMING0.bit.XRDACTIVE = 7;
XintfRegs.XTIMING0.bit.XRDTRAIL = 3;

// double all Zone read/write lead/active/trail timing
XintfRegs.XTIMING0.bit.X2TIMING = 1;

// Zone will sample XREADY signal
XintfRegs.XTIMING0.bit.USEREADY = 1;
XintfRegs.XTIMING0.bit.READYMODE = 1;  // sample asynchronous

// Size must be either:
// 0,1 = x32 or
// 1,1 = x16 other values are reserved
XintfRegs.XTIMING0.bit.XSIZE = 3;

// Zone 6------------------------------------
// When using ready, ACTIVE must be 1 or greater
// Lead must always be 1 or greater
// Zone write timing
XintfRegs.XTIMING6.bit.XWRLEAD = 3;
XintfRegs.XTIMING6.bit.XWRACTIVE = 7;
XintfRegs.XTIMING6.bit.XWRTRAIL = 3;
// Zone read timing
XintfRegs.XTIMING6.bit.XRDLEAD = 3;
XintfRegs.XTIMING6.bit.XRDACTIVE = 7;
XintfRegs.XTIMING6.bit.XRDTRAIL = 3;

// double all Zone read/write lead/active/trail timing
XintfRegs.XTIMING6.bit.X2TIMING = 1;

// Zone will sample XREADY signal
XintfRegs.XTIMING6.bit.USEREADY = 1;
XintfRegs.XTIMING6.bit.READYMODE = 1;  // sample asynchronous

// Size must be either:
// 0,1 = x32 or
// 1,1 = x16 other values are reserved
XintfRegs.XTIMING6.bit.XSIZE = 3;

// Zone 7------------------------------------
// When using ready, ACTIVE must be 1 or greater
// Lead must always be 1 or greater
// Zone write timing
XintfRegs.XTIMING7.bit.XWRLEAD = 3;
XintfRegs.XTIMING7.bit.XWRACTIVE = 7;
XintfRegs.XTIMING7.bit.XWRTRAIL = 3;
// Zone read timing
XintfRegs.XTIMING7.bit.XRDLEAD = 3;
XintfRegs.XTIMING7.bit.XRDACTIVE = 7;
XintfRegs.XTIMING7.bit.XRDTRAIL = 3;

// double all Zone read/write lead/active/trail timing
XintfRegs.XTIMING7.bit.X2TIMING = 1;

// Zone will sample XREADY signal
XintfRegs.XTIMING7.bit.USEREADY = 1;
XintfRegs.XTIMING7.bit.READYMODE = 1;  // sample asynchronous

// Size must be either:
// 0,1 = x32 or
// 1,1 = x16 other values are reserved
XintfRegs.XTIMING7.bit.XSIZE = 3;

// Bank switching
// Assume Zone 7 is slow, so add additional BCYC cycles
// when ever switching from Zone 7 to another Zone.
// This will help avoid bus contention.
XintfRegs.XBANK.bit.BANK = 7;
XintfRegs.XBANK.bit.BCYC = 7;
EDIS;
//Force a pipeline flush to ensure that the write to
//the last register configured occurs before returning.

InitXintf16Gpio();
// InitXintf32Gpio();

asm(" RPT #7 || NOP");

只看该作者 · 2017-2-22 09:33

598835484 发表于 2017-2-22 09:32
EALLOW;
XintfRegs.XINTCNF2.bit.XTIMCLK = 1;
// No write buffering

没找到对应DA的设置啊，请赐教

DSP例程DA转换程序为什么不用指定GPIO输出？

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