i2cse2pd.c

DSP28X通訊程式

/*=================================================================
File name   : I2CSE2PD.C                   
                    
Originator  : Digital Control Systems Group
              Texas Instruments

Description : This file contains the I2C bus Serial EEPROM driver 
              implemented using I2C master driver (GPIO)                        

Target      : C28x

Date        : 30/01/2002 (DD/MM/YYYY)
====================================================================*/
                                                                    
#include "..\include\i2cse2p.h"
#include "..\include\i2cm_io.h"


static VI2CM_IO i2c=VI2CM_IO_DEFAULTS;  

/********************************************************************/
/******* I2C bus Serial EEPROM driver Initialization routine ********/ 
/********************************************************************/

void I2CSE2P_init(I2CSE2P_IO *eeprom)
{   
    i2c.init(&i2c);
    eeprom->csr=0;
    eeprom->msgPtr=0;
}

/********************************************************************/
/******* I2C bus Serial EEPROM driver Tick function *****************/ 
/********************************************************************/
                                                                    
void I2CSE2P_tick(I2CSE2P_IO *eeprom)
{
    static int step=0;
    static int dataCount=0;


    switch(step)
    {
    case 0: 
        /* If write request is SET, then trigger the Write operation    
           If read request is SET, then trigger the Read operation
           If Read request is also not SET, then continue to poll   */
     
        if(eeprom->csr&I2CSE2P_WRRQ)
        { step=1;
          eeprom->csr|=I2CSE2P_WRIP;        /*Set Write in progress */
        }

        
        if(eeprom->csr&I2CSE2P_RDRQ)
        { step=1;
          eeprom->csr|=I2CSE2P_RDIP;        /* Set Read in progress */
        }  
        
        break;
        
        /************************************************************    
        *********** Send Control + Address  *************************
        *************************************************************/

    case 1:
        /* Issue START Condition                                    */  
        i2c.taskIndex=START_CMD;
        step++;
        break;

    case 2:
        /* Wait for START & Send device Id/block number             */
        if(i2c.taskIndex == IDLE_STATE)
        { i2c.I2CDAT=(0xA0)|(((eeprom->msgPtr->Did_Blknr)&0x7)<<1);
        
        /* Issue Transmit command                                   */
          i2c.taskIndex=TXMIT_CMD;
          step++;
        }
        break;

    case 3:         
        /* Wait for the device Id or Black number transmission      */   
        if(i2c.taskIndex==IDLE_STATE)
        { if(i2c.I2CCSR & I2C_ACKSTAT)
           step=16;                 /* No Ack from slave, re-try    */
          else
          {  
            #if ADDRWIDTH==TWOBYTE
            i2c.I2CDAT=( (eeprom->msgPtr->addr)&0xFF00)>>8;
            #endif
               
            #if ADDRWIDTH==ONEBYTE
            i2c.I2CDAT=((eeprom->msgPtr->addr) );
            #endif
        /* Issue Transmit command                                   */
            i2c.taskIndex=TXMIT_CMD;
            step++;
          }
        }
        break;
    
    
    case 4:
        /* Wait for address transmit. send second address, if any   */   
        if(i2c.taskIndex == IDLE_STATE)
        { if(i2c.I2CCSR & I2C_ACKSTAT)
          { eeprom->csr|=I2CSE2P_ERR;   /* Error Occured, Issue Stop*/
            step=14;
          }
          else
          {  
            #if ADDRWIDTH==TWOBYTE
            i2c.I2CDAT=eeprom->msgPtr->addr;              
        /* Issue Transmit command                                   */
            i2c.taskIndex=TXMIT_CMD;
            #endif
            step++;
          }
        }
            break;
    
    case 5:
        /* Wait for Second address transmit                         */
        if(i2c.taskIndex == IDLE_STATE)
        { if(i2c.I2CCSR & I2C_ACKSTAT)
          { eeprom->csr|=I2CSE2P_ERR;   /* Error Occured, Issue Stop*/
            step=14;
          }
          else
          { /* Check Read or Write                                  */  
            if(eeprom->csr & I2CSE2P_WRIP)
             step++;
            else
             step=8;
          }
        }
        break;

        /***********************************************************/
        /************ Serial EEPROM Write operation ****************/
        /***********************************************************/

    case 6:
        /* Send Data                                                */
        i2c.I2CDAT=*(eeprom->msgPtr->dataPtr+dataCount); 
        /* Issue Transmit command                                   */
        i2c.taskIndex=TXMIT_CMD;
        step++;
        dataCount++;
        break;   

    case 7:  
        /* Wait for data transmission and check Ack                 */
        if(i2c.taskIndex == IDLE_STATE)
        { if(i2c.I2CCSR & I2C_ACKSTAT)
          { eeprom->csr|=I2CSE2P_ERR;   /* Error Occured, Issue Stop*/
            step=14;
          }
          else
          {  
            if (dataCount==eeprom->msgPtr->nrData)
             step=14;                   /* Issue STOP condition     */
            else
             step--;
          }
        }
        break;


        /***********************************************************/
        /************ Serial EEPROM Read operation *****************/
        /***********************************************************/

    case 8:
        /*  Issue Sr (Repeat Start Condition)                       */
        i2c.taskIndex=RSTART_CMD;
        step++;
        break;

    case 9:
        /* Wait for Sr & Send device Id/block number                */
        if(i2c.taskIndex == IDLE_STATE)
        { i2c.I2CDAT=(0xA1)|((eeprom->msgPtr->Did_Blknr&0x7)<<1);
                
        /* Issue Transmit command                                   */
          i2c.taskIndex=TXMIT_CMD;
          step++;
        }
        break;

    case 10:     
        /* Wait for device Id/block number txmit                    */
        if(i2c.taskIndex == IDLE_STATE)
        { if(i2c.I2CCSR & I2C_ACKSTAT)
          { eeprom->csr|=I2CSE2P_ERR;   /* Error Occured, Issue Stop*/
            step=14;
          }
          else
           step++;
        }
        break;

    case 11:
        /* Enable Receive operation                                 */  
        i2c.taskIndex=RECV_CMD;
        step++;
        break;
    case 12:  
       /* Wait for receive                                          */
        if(i2c.taskIndex == IDLE_STATE)
        { *(eeprom->msgPtr->dataPtr+dataCount)=(i2c.I2CDAT);
          dataCount++;
          step++;
              
          if (dataCount==eeprom->msgPtr->nrData)
           i2c.I2CCSR|=I2C_ACKDT;       /* Acknowledge=1            */
          else
           i2c.I2CCSR&=(~I2C_ACKDT);    /* Acknowledge=0            */
     
          i2c.taskIndex=ACK_CMD;        /* Issue Acknowledge        */
         }
         break;


    case 13: 
        /* Send Acknowledge to serial EEPROM                        */
        if(i2c.taskIndex == IDLE_STATE)
         { if (dataCount==eeprom->msgPtr->nrData)
            step++;
           else
            step=step-2;
         }          
         break;
         
        /***********************************************************/
        /************ STOP Condition *******************************/
        /***********************************************************/

    case 14: 
        /* Issue STOP Condition                                     */  
        i2c.taskIndex=STOP_CMD;
        step++;
        break;
           
    case 15: 
        /* Wait for STOP condition                                  */  
        if(i2c.taskIndex == IDLE_STATE)
        { eeprom->csr&=~(I2CSE2P_RDIP | I2CSE2P_WRIP);
          eeprom->csr&=~(I2CSE2P_RDRQ | I2CSE2P_WRRQ);
          step=0;
          dataCount=0;
        }
        break;

        /***********************************************************/
        /************ Error handling *******************************/
        /***********************************************************/

    case 16:
        /* Issue STOP condition and re-try                          */
        i2c.taskIndex=STOP_CMD;
        step++;
        break;
    
    case 17:
        /* Wait for STOP condition and Re-try                       */  
        if(i2c.taskIndex == IDLE_STATE)
          step=1;
        break;

    }
   i2c.tick(&i2c); 
}