Hi everyone, 
I am trying to setup a I2C comm between the two PIC18F2620s. The Master writes correctly to the slave, but when it tries to read back, it gets stuck at the "while" statement in the ReadI2C function. 
 
unsigned char ReadI2C( void )
{
  SSPCON2bits.RCEN = 1;           // enable master for 1 byte reception
  while ( !SSPSTATbits.BF );      // wait until byte received  
  return ( SSPBUF );              // return with read byte 
}
 
I tried many different ways for more than a week now, but none of them works. Both PICs run at 8Mhz crystal + PLL = 32Mhz. I use MCC18 V2.44 with MPLAB 7.21.  Please help!  Thank you in advance.
 
Master Code: 
#include <p18f2620.h>
#include <delays.h>
#include <i2c.h>
unsigned char Temp1, Temp2;
void main (void)
{
  TRISA = 0b00100000;
  TRISC = 0b11110111;
  
  OpenI2C(MASTER, SLEW_OFF);
  SSPADD = 0x4F;              // 100khz @ 32Mhz crystal
  IdleI2C();                  // test for idle condition
  StartI2C();
  
  IdleI2C();                  // test for idle condition
  WriteI2C(0xA0);             // addr byte
  
  IdleI2C();                  // test for idle condition
  WriteI2C(0x01);             // MSB word address
  
  IdleI2C();                  // test for idle condition
  WriteI2C(0x02);             // LSB word address
  
  IdleI2C();                  // test for idle condition
  StopI2C();
  IdleI2C();                  // test for idle condition
  StartI2C();
  
  IdleI2C();                  // test for idle condition
  WriteI2C(0xA1);                 // addr byte
  
  IdleI2C();                  // test for idle condition  
  Temp1 = ReadI2C();              // read the byte
  while ( SSPCON2bits.RCEN );   // check that receive sequence is over
  SSPCON2bits.ACKDT = 0;        // set acknowledge bit state for ACK        
  SSPCON2bits.ACKEN = 1;        // initiate bus acknowledge sequence
  while ( SSPCON2bits.ACKEN );  // wait until ACK sequence is over 
  IdleI2C();                  // test for idle condition     
  Temp2 = ReadI2C();            // read the byte
  while ( SSPCON2bits.RCEN );   // check that receive sequence is over
  SSPCON2bits.ACKDT = 0;        // set acknowledge bit state for ACK        
  SSPCON2bits.ACKEN = 1;        // initiate bus acknowledge sequence
  while ( SSPCON2bits.ACKEN );  // wait until ACK sequence is over  
  IdleI2C();                  // test for idle condition
  StopI2C();
  
  while (1)
  {
    PORTAbits.RA4 = 0;        // OFF
    Delay10KTCYx(200);
    PORTAbits.RA4 = 1;        // ON
    Delay10KTCYx(200);
  }
}
 
Slave Code: 
#include <p18f2620.h>
#include <i2c.h>
unsigned char Temp1, Temp2, Status;
void main (void)
{
  TRISA = 0b00100000;
  TRISC = 0b11111111; 
  PIR1 = 0x00;
  OpenI2C(SLAVE_7, SLEW_OFF);
  SSPADD = 0xA0;
  SSPSTAT = 0x00;
  PIR1bits.SSPIF = 0;
  PIE1bits.SSPIE = 1;             //i2c
  IPR1bits.SSPIP = 1;             // high
  RCONbits.IPEN = 1;              // Enable Priority interrupt
  INTCONbits.GIEH = 1;            // init GIEH
  INTCONbits.GIEL = 1;            // init GIEL
  
  while (1)
  {
    PORTAbits.RA4 = 0;        // OFF
    Delay10KTCYx(200);
    PORTAbits.RA4 = 1;        // ON
    Delay10KTCYx(200);
  } 
}
#pragma interrupt high_isr
void high_isr(void)
{
  if (PIR1bits.SSPIF && PIE1bits.SSPIE)   // i2c Interrupt
  {
    Status = SSPSTAT & 0b00101101;
    PIR1bits.SSPIF = 0;                 // clear flag
    
    // I2C write operation, last byte was an address byte.
    if ((Status ^ 0b00001001) == 0)       // state1
      Temp1 = ReadI2C();                  // dummy read
    
    // I2C write operation, last byte was a data byte.
    else if ((Status ^ 0b00101001)  == 0)       // state2
    {
      Temp1 = Temp2;
      Temp2 = ReadI2C();
    }
    // I2C read operation, last byte was an address byte.
    else if ((Status ^ 0b00001100)  == 0)       // state3
    {
      WriteI2C(0x51);
      SSPCON1bits.CKP = 1;
     }
    
    // I2C read operation, last byte was a data byte.
    else if ((Status ^ 0b00101100)  == 0)       // state4
    {
      WriteI2C(0x52);
      SSPCON1bits.CKP = 1;
     }
      
    // Slave I2C logic reset by NACK from master.
    else if ((Status ^ 0b00101000)  == 0)       // state5
      Nop();
  }
}
#pragma code high_vector=0x08
void high_interrupt(void)
{
  _asm GOTO high_isr _endasm
}
#pragma code

		
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