www.pudn.com > SCIB_RS232.rar > DSP281x_Xintf.c

//########################################################################### 
// 
// FILE:   DSP281x_Xintf.c 
// 
// TITLE:   DSP281x Device External Interface Init & Support Functions. 
// 
//########################################################################### 
 
#include "DSP281x_Device.h"     // DSP281x Headerfile Include File 
#include "DSP281x_Examples.h"   // DSP281x Examples Include File 
 
//--------------------------------------------------------------------------- 
// InitXINTF:  
//--------------------------------------------------------------------------- 
// This function initializes the External Interface the default reset state. 
// 
// Do not modify the timings of the XINTF while running from the XINTF.  Doing 
// so can yield unpredictable results 
 
 
void InitXintf(void) 
{ 
 
    // This shows how to write to the XINTF registers.  The 
    // values used here are the default state after reset. 
    // Different hardware will require a different configuration. 
         
    // All Zones--------------------------------- 
    // Timing for all zones based on XTIMCLK = SYSCLKOUT  
    XintfRegs.XINTCNF2.bit.XTIMCLK = 1;		//XTIMCLK = 1/2 SYSCLK = 75MHZ	 
    //XintfRegs.XINTCNF2.bit.XTIMCLK = 0;   //XTIMCLK =  SYSCLK = 150MHZ	 
     
    // No write buffering 
    XintfRegs.XINTCNF2.bit.WRBUFF = 0; 
    // XCLKOUT is abled 
    XintfRegs.XINTCNF2.bit.CLKOFF = 0; 
    // XCLKOUT = XTIMCLK  
     
    //XintfRegs.XINTCNF2.bit.CLKMODE = 1;	//CLKģʽ1v£¬ CLKOUT = 1/2XTIMECLK 
    XintfRegs.XINTCNF2.bit.CLKMODE = 0;		//CLKģʽ0£¬ CLKOUT = XTIMECLK 
    
     
    // 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;          
     
    // Not double all Zone read/write lead/active/trail timing  
    XintfRegs.XTIMING0.bit.X2TIMING = 0; 
 
    // Zone will not sample XREADY signal  
    XintfRegs.XTIMING0.bit.USEREADY = 0; 
    XintfRegs.XTIMING0.bit.READYMODE = 1;        // sample asynchronous 
 
    // Size must be 1,1 - other values are reserved 
    XintfRegs.XTIMING0.bit.XSIZE = 3; 
     
    // Zone 1------------------------------------ 
    // When using ready, ACTIVE must be 1 or greater 
    // Lead must always be 1 or greater 
    // Zone write timing 
    XintfRegs.XTIMING1.bit.XWRLEAD = 3; 
    XintfRegs.XTIMING1.bit.XWRACTIVE = 7; 
    XintfRegs.XTIMING1.bit.XWRTRAIL = 3; 
    // Zone read timing 
    XintfRegs.XTIMING1.bit.XRDLEAD = 1; 
    XintfRegs.XTIMING1.bit.XRDACTIVE = 2; 
    XintfRegs.XTIMING1.bit.XRDTRAIL = 1; 
     
    // double all Zone read/write lead/active/trail timing  
    XintfRegs.XTIMING1.bit.X2TIMING = 0; 
 
    // Zone will sample XREADY signal  
    XintfRegs.XTIMING1.bit.USEREADY = 0; 
    XintfRegs.XTIMING1.bit.READYMODE = 1;  // sample asynchronous 
 
    // Size must be 1,1 - other values are reserved 
    XintfRegs.XTIMING1.bit.XSIZE = 3; 
 
    // Zone 2------------------------------------ 
    // When using ready, ACTIVE must be 1 or greater 
    // Lead must always be 1 or greater 
    // Zone write timing 
    XintfRegs.XTIMING2.bit.XWRLEAD = 3;           
    XintfRegs.XTIMING2.bit.XWRACTIVE = 7;         
    XintfRegs.XTIMING2.bit.XWRTRAIL = 3;          
    // Zone read timing 
    XintfRegs.XTIMING2.bit.XRDLEAD = 1;           
    XintfRegs.XTIMING2.bit.XRDACTIVE = 2;         
    XintfRegs.XTIMING2.bit.XRDTRAIL = 1;          
     
    // Not double all Zone read/write lead/active/trail timing  
    XintfRegs.XTIMING2.bit.X2TIMING = 0; 
 
    // Zone will not sample XREADY signal  
    XintfRegs.XTIMING2.bit.USEREADY = 0; 
    XintfRegs.XTIMING2.bit.READYMODE = 1;  // sample asynchronous 
 
    // Size must be 1,1 - other values are reserved 
    XintfRegs.XTIMING2.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 1,1 - 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 1,1 - 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; 
 
   //Force a pipeline flush to ensure that the write to  
   //the last register configured occurs before returning.   
 
   asm(" RPT #7 || NOP");  
     
    
} 
 
//=========================================================================== 
// No more. 
//===========================================================================