spi.c

基于dsp55系列的指纹识别系统。已调试通过

/****************************************************************************
*
*             
*             TEXAS INSTRUMENTS PROPRIETARY INFORMATION
*
*  (c) Copyright, Texas Instruments Incorporated, 2003.
*      All Rights Reserved.
*
*  Property of Texas Instruments Incorporated. Restricted Rights -
*  Use, duplication, or disclosure is subject to restrictions set
*  forth in TI's program license agreement and associated documentation.
*
***************************************************************************** 
*****************************************************************************
*
* NAME: spi.c
*   
*
* DESCRIPTION: functions to read complete image from FPC1010 sensor.
*   
*
*   CREATED:       05/20/2002 
*   MODIFIED:      06/13/2003 
*   
*
****************************************************************************/


	


#include <csl.h>
#include <csl_mcbsp.h>   

#include "spi.h"


MCBSP_Handle hMcbsp0;

/*
 * Function name :  SPI_txReady
 * Arguments     :  none              
 * Return value  :  none
 * Exceptions    : 
 * Description   :  waits till master is ready for transmission.
 */
void SPI_txReady(void)
{



unsigned char t;
	
	do{
	
	//0x2804 Port Address:McBSP 0 Serial Port Control Register 2(SPCR2_0)
	t = *(unsigned volatile ioport *)0x2804;
	}
	while (!( t & 0x02));

}

/*
 * Function name :  SPI_rxReady
 * Arguments     :  none              
 * Return value  :  none
 * Exceptions    : 
 * Description   :  waits till the slave is transmits the data ti master.
 */
void SPI_rxReady(void)
{


	unsigned char temp;
	do{
	////0x2805 Port Address:McBSP 0 Serial Port Control Register 1(SPCR1_0)
	temp = *(unsigned volatile ioport *)0x2805;
	}
	while (!( temp & 0x02));


}

/*
 * Function name :  SPI_init
 * Arguments     :  pcrValue , Frequency , xcr2 value            
 * Return value  :  if succes then returns 0 else error
 * Exceptions    : 
 * Description   :  initializes the McBSP 0 for SPI communication.
 */
void SPI_init(unsigned char pcrValue,unsigned char frequency,unsigned char xcr2Value)
{

 /* Open MCBSP Port 0, this will return a MCBSP handle that will */
  /* be used in calls to other CSL functions.                     */



hMcbsp0 = MCBSP_open(MCBSP_PORT0, MCBSP_OPEN_RESET);


 
 MCBSP_RSETH(hMcbsp0,SPCR1,0x0000);
 
 MCBSP_RSETH(hMcbsp0, SPCR2,0x0000);
 
//;;Step 2
//;;Write PCR0 address into SPSA0

 MCBSP_RSETH(hMcbsp0, PCR,pcrValue);
  
// ;;Write into RCR10 address into SPSA0
 MCBSP_RSETH(hMcbsp0,RCR1 ,0x0000);
                  
 MCBSP_RSETH(hMcbsp0,RCR2 ,0x000D);
 
//Write into XCR10 address into SPSA0
 MCBSP_RSETH(hMcbsp0, XCR1,0x0000);
                  
 MCBSP_RSETH(hMcbsp0, XCR2,xcr2Value);
 
//Write into SPSA0 with SPCR10 clkstop mode enabled
 MCBSP_RSETH(hMcbsp0,SPCR1 ,0x1800);
                  
 MCBSP_RSETH(hMcbsp0,SPCR2 ,0x0080);
                  
  
//Write into SPSA0 with SRGR10 address
 MCBSP_RSETH(hMcbsp0,SRGR1 ,frequency);
                  
 MCBSP_RSETH(hMcbsp0, SRGR2,0x2000);
 
 
//;;Step3
//;;set GRST = 1 in spcr20
//;;write SPCR20 address with SPSA0 

                  
 MCBSP_RSETH(hMcbsp0,SPCR2 ,0x00C0);
  
//Step4
//;;delay
 
//Step5 
//;;Write into SPSA0 with SPCR10 address  
 MCBSP_RSETH(hMcbsp0, SPCR1,0x1801);
//;Write into SPSA0 with SPCR20 address

 MCBSP_RSETH(hMcbsp0, SPCR2,0x00C3);
  /* end init */
}
/*
 * Function name :  SPI_txChar
 * Arguments     :  character to be written to the slave          
 * Return value  :  none
 * Exceptions    : 
 * Description   :  write the argument character to slave.
 */
void SPI_txChar(unsigned char character)
{
	unsigned char t;
    SPI_txReady(); 
	/* write the command */
    MCBSP_RSETH(hMcbsp0, DXR1,character);
    
    /* dummy read always needed */
    SPI_rxReady();

 	t = MCBSP_RGETH(hMcbsp0, DRR1);
}
/*
 * Function name :  SPI_rxChar
 * Arguments     :  none
 * Return value  :  character
 * Exceptions    : 
 * Description   :  write the character from to slave.
 */
unsigned char SPI_rxChar(void)
{
	unsigned char character;
    SPI_txReady(); 
	/* write dummy byte to receive the image byte  */
	 MCBSP_RSETH(hMcbsp0, DXR1,0xFF);
	 
	SPI_rxReady(); 
     character = MCBSP_RGETH(hMcbsp0,DRR1);    
    
	return character;
}

/*
 * Function name :  SPI_close
 * Arguments     :  none               
 * Return value  :  none
 * Exceptions    : 
 * Description   :  close the spi connection
 */
void SPI_close(void)
{
    MCBSP_close(hMcbsp0);
}