void i2c_init(u08 address)
{
    i2c_Address = address;

    PORT_USI |= (1<<PORT_USI_SCL);                    // Set SCL high
    PORT_USI |= (1<<PORT_USI_SDA);                    // Set SDA high
    DDR_USI |= (1<<PORT_USI_SCL);                    // Set SCL as output
    DDR_USI &= ~(1<<PORT_USI_SDA);                    // Set SDA as input
    USICR =    (1<<USISIE)|(0<<USIOIE)|                // Enable Start Condition Interrupt. Disable Overflow Interrupt.
            (1<<USIWM1)|(0<<USIWM0)|                // Set USI in Two-wire mode. No USI Counter overflow prior
                                                    // to first Start Condition (potentail failure)
            (1<<USICS1)|(0<<USICS0)|(0<<USICLK)|    // Shift Register Clock Source = External, positive edge
            (0<<USITC);
    USISR    = 0xF0;                                // Clear all flags and reset overflow counter
}

        if( USI_TWI_statusReg.dataInRxBuf )
        {
              PORTB |= (1 << LED);
                 ........

void ReadSensor()    
{
    I2c_StartWait(SENSOR_ADDR | W);         // slave address, write to sensor
    I2c_Write(TWI_CMD_MASTER_READ);  
  
    I2c_RepStart(SENSOR_ADDR | R);   // slave address + read bit, read sensor
          
    Value = (unsigned long)I2c_Read(I2C_ACK) << 24;
    Value |= (unsigned long)I2c_Read(I2C_ACK) << 16;
    Value |= (unsigned long)I2c_Read(I2C_ACK) << 8;
    Value |= (unsigned long)I2c_Read(I2C_NACK) << 0;
  
    I2c_Stop();
}

(( USIDR>>1 ) == TWI_slaveAddress

#define SENSOR_ADDR  0x10

    I2c_StartWait(SENSOR_ADDR | W);         // slave address, write to sensor
    I2c_Write(TWI_CMD_MASTER_READ);  
  
    I2c_RepStart(SENSOR_ADDR | R);   // slave address + read bit, read sensor

TWI_slaveAddress = 0x08;
............
    case USI_SLAVE_CHECK_ADDRESS:
      if ( ( USIDR == 0 ) || ( ( USIDR >> 1 ) == slaveAddress) )
      {
          if ( USIDR & 0x01 )
        {
          overflowState = USI_SLAVE_SEND_DATA;
        }
        else
        {
          overflowState = USI_SLAVE_REQUEST_DATA;
        }
        SET_USI_TO_SEND_ACK( );
      }
.......

unsigned char send_byte(unsigned char val)
{
   USIDR = val;
   USISR = (1<<USIOIF);
   do
   {
      USICR = (1<<USIWM0) | (1<<USICS1) | (1<<USICLK) | (1<<USITC);
   }
   while ((USISR & (1<<USIOIF)) == 0);
  
   return USIDR;
}

void main()
{
    SETBIT(DDRB, USCK);
    SETBIT(PORTB, USCK);
    
    SETBIT(DDRB, DO);
    CLRBIT(PORTB, DO);
    
    CLRBIT(DDRB, DI);
    SETBIT(PORTB, DI);
        
    for(;;)
    {    
        SendByte(0x11);
        
        delay_ms(100);
    }
}

    // select clock phase negative-going in middle of data
    SPCR |= (1 << CPOL0);
        
        // data is sampled on the trailing (last) edge of SCK. SPI Mode - 3
        SPCR |= (1 << CPHA0);
        
    // Data order MSB first
    SPCR &= ~(1 << DORD0);
        
    // enable SPI
    SPCR |= (1 << SPE0);
    
    // clear status
    SPSR = SPSR;
    SpiTransferComplete = true;

    // enable SPI interrupt
    #ifdef SPI_USEINT
    SPCR |= (1 << SPIE0);
    #endif
}

void SendByte(unsigned char Data)
{
    unsigned char BitCount = 8;

    do
    {
        // Send bit to Slave, MSB first
        if(Data & 0x80)
        {
            SETBIT(PORTB, DO);
        }
        else
        {
            CLRBIT(PORTB, DO);
        }
        
        // Toggle SCK pin to send current bit
        CLRBIT(PORTB, USCK);
        SETBIT(PORTB, USCK);        
                
        // Get next bit to send
        Data <<= 1;      
    }
    while(--BitCount);

}

    for(;;)
    {    
        if(usiTwiSlave.available())
        {
            //usiTwiSlave.receive();

            usiTwiSlave.write((unsigned char)(Value >> 24));
            usiTwiSlave.write((unsigned char)(Value >> 16));
            usiTwiSlave.write((unsigned char)(Value >> 8));
            usiTwiSlave.write((unsigned char)(Value >> 0));
        }
    }

void ReadSensor()    
{
    I2c_StartWait(SENSOR_ADDR | W);  // slave address, write to capsensor  SENSOR_ADDR
    I2c_Write(TWI_CMD_MASTER_READ);  
  
    I2c_RepStart(SENSOR_ADDR | R);   // slave address + read bit, read capsensor SENSOR_ADDR
          
    ValueOfCharge = (unsigned long)I2c_Read(I2C_ACK) << 24;
    delay_ms(100);
    ValueOfCharge |= (unsigned long)I2c_Read(I2C_ACK) << 16;
    delay_ms(100);
    ValueOfCharge |= (unsigned long)I2c_Read(I2C_ACK) << 8;
    delay_ms(100);
    ValueOfCharge |= (unsigned long)I2c_Read(I2C_NACK) << 0;
  
    I2c_Stop();
}

.include "tn45def.inc"

.def temp =r16
.def USIcnt =r19
.def USIstate =r20



.org 0
RJMP reset;RESET External Pin, Power-on Reset, Brown-out
RJMP reset;INT0 External Interrupt Request 0
RJMP reset;PCINT0 External Interrupt Request 1
RJMP reset;TIMER1 COMPA Timer/Counter1 Compare Match A
RJMP reset;TIMER1 OVF Timer/Counter1 Overflow
RJMP reset;TIMER0 OVF Timer/Counter0 Overflow
RJMP reset;EE_RDY EEPROM Ready
RJMP reset;ANA_COMP Analog Comparator
RJMP reset;ADC ADC Conversion Complete
RJMP reset;TIMER1 COMPB Timer/Counter1 Compare Match B
RJMP reset;TIMER0 COMPA Timer/Counter0 Compare Match A
RJMP reset;TIMER0 COMPB Timer/Counter0 Compare Match B
RJMP reset;WDT
RJMP USIstart;USI - start
RJMP USIofl;USI - Overflow
;-----------------------
USIstart:
push temp

ldi temp,1
mov USIstate,temp


in temp,USICR;(Enable USI Counter overflow interrupt)
sbr temp,0b01000000
out USICR,temp
rcall ClearACK
pop temp
reti

USIofl:
push temp


mov temp,USIstate
cpi temp,1
breq I2Cadr
cpi temp,2
breq I2Cack
cpi temp,3
breq I2Cbyte

rjmp USIend

I2Cadr:
in temp,USIDR
cpi temp,0b11111110
breq I2Calladr
cpi temp,0b00000100
brne I2Cbadadr

; cbi portb,1

ldi xl,low(0x80);Set pointer on the first received byte
ldi xh,high(0x80);адрес буфера дл япримеа

rcall SetACK

ldi temp,2
mov USIstate,temp
clr USIcnt
rjmp USIend

I2Cack:
rcall ClearACK

inc USIcnt
mov temp,USIcnt
cpi temp,6; сколько приянть байтов
breq I2Call

ldi temp,3
mov USIstate,temp
rjmp USIend


I2Cbyte:

in temp,USIDR
st X+,temp; прияняли очередной байт
rcall SetACK

ldi temp,2
mov USIstate,temp
rjmp USIend

I2Calladr:
; пришел шыроковещательный пакет

rjmp I2Cbadadr
I2Call:
; sbi portb,1
; прияны все данные!

I2Cbadadr:
rcall StopDetected

USIend:
pop temp
reti
;--------
SetACK:
sbi DDRB,0
sbi PortB,2
sbi DDRB,2

in temp,USISR
cbr temp,0b00000001;(Set counter to 0xE)
sbr temp,0b11101110;(Enable new interrupts. Releasing SCL)
out USISR,temp
ret


StopDetected:

in temp,USICR;(Disable USI Counter overflow interrupt)
cbr temp,0b01000000
out USICR,temp

ClearACK:

cbi DDRB,0
cbi PortB,2
cbi DDRB,2

in temp,USISR
cbr temp,0b00001111;(Clear counter)
sbr temp,0b11100000;(Enable new interrupts. Releasing SCL)
out USISR,temp
ret
;------------------
reset:

ldi temp,high(RAMEND);High byte only required if
out SPH,temp ;RAM is bigger than 256 Bytes
ldi temp,low(RAMEND)
out SPL,temp

ldi temp,0b00000010
out PORTB,temp
ldi temp,0b00000010
out DDRB,temp

ldi temp,(1<<USISIE)+(1<<USIWM1)+(1<<USIWM0)+(1<<USICS1)
out USICR,temp
ldi temp,0xf0
out USISR,temp

ldi Zh,HIGH(reset)
ldi Zl,LOW(reset)

ldi temp, 0b00100000
out MCUCR,temp

sei

clr USIstate


loop:
sleep
rjmp loop