I am simulating a master-slave scenario. the master is the PIC18F4620, the slave is the I2C debugger.

I am sending a slave address of 0x04. R/W = 0 to perform a write operation on the slave.

This is my frame format.

 //Slave address is 0x04. mcal_i2c_send_slave_address(0x04,0,&ack_status); //Send data = 0x77 mcal_i2c_master_send_data(0x77,&ack_status); //send repeated start mcal_i2c_send_repeated_start_condition(); //send data = 0x00 , then send stop condition. mcal_i2c_master_send_data(0x00,&ack_status); mcal_i2c_send_stop_condition(); 

The transmitter which is the PIC18F is transmitting the frame correctly. But the problem is that the I2C debugger won`t send ACK, it only sends not ACK. Does anybody know why I am receiving NACK from the i2C debugger?