Sitemap ::info-rlp :: PSPICE  :: C-Programmierung :: AT04 :: ELI04 :: C51 :: 

 

1.
	Problemstellung

 

    

3.
	Programmablaufplan

- Programmablaufplan (PAP)

   siehe Keil C51/Philips LPC900, S. ????? ff


   

2.
	SAA1064

 

 Datenblatt

 

4.
	Struktogramm

- Struktogramm

 

4.
	Quellcode in der  Programmiersprache C  Dokumentation zum LPC900-Experimentierboard (LPC-Experimentierboard.pdf)  Quelltext

/**************************************************************************************
 *  C-Programm zur Auswertung von externen Ereignissen                                  *
 *  Projekt-Name: i2c_bus_ansteuerung_7_segment_led.uv2                               *
 **************************************************************************************/

#include <reg932.h>


unsigned int uiLoop;
enum enSAASEG {NULL = 0x3F, EINS = 0x06,
                               ZWEI = 0x5B, DREI = 0x4F,
                               VIER = 0x66, FUENF = 0x6D,
                               SECHS = 0x7D, SIEBEN = 0x07,
                               ACHT = 0x7F, NEUN = 0x67,
                               PUNKT = 0x80};

struct stI2C
{
    unsigned char Adr;
    unsigned char DataLen;
    unsigned char Val[10];
};

struct stI2C Slave;
bit btI2cFinished;

v_InitI2C(void)
{
    P1M1 |= 0x0C;                               // SDA und SCL als Open-Drain
    P1M2 |= 0x0C;
    I2SCLH = 19;                                 // I2C-Geschwindigkeit ~100 KHz
    I2SCLL = 19;
    I2CON = 0x44;                               // I2C-Hardware aktivieren (STO, STA, SI = 0, ACK =1)
    EI2C = 1;                                        // I2C Interrupt freigeben
}

v_SetNextI2CVal( unsigned char ucVal )
{
    Slave.Val[Slave.DataLen] = ucVal;
    Slave.DataLen++;
}

v_StartI2CTrans( void )
{
    btI2cFinished = 0;
    I2CON = 0x64;                                                         // Startbedingung setzen
}

void v_WaitI2CFinish(void)
{
    while (btI2cFinished == 0);
}

main()
{
    unsigned char ucVal;
    v_InitI2C();
    EA = 1;                                                                        // allgemeine Interruptsperre aufheben
    Slave.Adr = 0x70;                                                        // Adresse SAA1064
    v_SetNextI2CVal( 0 );                                                  // set Subadresse auf 0 (Control-Byte)
    v_SetNextI2CVal( 0xF7 );                                            // dynamic alternating mode (digits 1+3 and 2+4)
    v_StartI2CTrans();
    v_WaitI2CFinish();
    while( 1 )
    {
        v_SetNextI2CVal( 1 );
        switch ( ucVal )
        {
            case 0x00: v_SetNextI2CVal( NULL ); break;
            case 0x01: v_SetNextI2CVal( EINS ); break;
            case 0x02: v_SetNextI2CVal( ZWEI ); break;
            case 0x03: v_SetNextI2CVal( DREI ); break;
            case 0x04: v_SetNextI2CVal( VIER ); break;
            case 0x05: v_SetNextI2CVal( FUENF ); break;
            case 0x06: v_SetNextI2CVal( SECHS ); break;
            case 0x07: v_SetNextI2CVal( SIEBEN ); break;
            case 0x08: v_SetNextI2CVal( ACHT ); break;
            case 0x09: v_SetNextI2CVal( NEUN ); break;
            default:
            v_SetNextI2CVal( 0xF7 );
        }

        v_StartI2CTrans();
        v_WaitI2CFinish();

       if( ucVal == 0x09 )
       {
           ucVal = 0x00;                                                          // Rücksetzung des Zählers
       }

       ucVal++;

       for( uiLoop = 0; uiLoop < 50000; uiLoop++ );       // Wartezeit, sonst Zählung nicht sichtbar

     }

    }

unsigned char ucI2COff;
void vI2C_Interrupt( void ) interrupt 6
{
    switch( I2STAT )                                                             // Auswertung des Statusregisters
    {
        case 0x08:                                                                  // Status: "START transmitted"
        I2DAT = Slave.Adr;
        ucI2COff = 0;
        I2CON = 0x44;                                                            // (STO, STA, SI = 0, ACK =1)
        break;
        case 0x18:                                                                   // Status: "SLA+W transmitted; ACK received"
        case 0x28:                                                                   // Status: "byte transmitted; ACK received"
        if ( ucI2COff < Slave.DataLen )
        {
            I2DAT = Slave.Val[ucI2COff];                                  // set next value
            ucI2COff++;
            I2CON = 0x44;
        }

       else
       {
           Slave.DataLen = 0;
           btI2cFinished = 1;
           I2CON = 0x54;                                                          // Stoppbedingung setzen (STO =1)
       }

       break; 
       case 0x20:                                                                     // Status:    "SLA+W transmitted; NOT ACK  
       received"
       I2CON = 0x54;                                                               // Stoppbedingung setzen (STO =1)
       break;
       default:
       Slave.Adr = I2STAT ;
       break;
       }
}