SAM4SD32 TWI I2C TWI_MMR MREAD read write bit

#include <asf.h>

#define I2C_BUS1_ADDR_U5 0b1111001

int main (void)

{

  // Initialisierungen

  MATRIX->CCFG_SYSIO |= (1 << 4) | (1 << 5);

  board_init();

  sysclk_init();

  delay_init(sysclk_get_cpu_hz());

  pio_set_peripheral(PIOB,PIO_PERIPH_A,PIO_PB5);

  pio_set_peripheral(PIOB,PIO_PERIPH_A,PIO_PB4);

  pio_set_output(PIOA, PIO_PA31, LOW, DISABLE, ENABLE);

  pio_clear(PIOA,PIO_PA31);

  pmc_enable_periph_clk(ID_PIOA); 

  pmc_enable_periph_clk(ID_TWI1);

  twi_master_options_t opt = {

    .speed = 100000,

    .chip  = I2C_BUS1_ADDR_U5,

    //.smbus = 0,

    .master_clk = sysclk_get_peripheral_bus_hz(TWI1)

  };

  twi_master_setup(TWI1, &opt);

  //twi_disable_highspeed(TWI1);

  twi_master_enable(TWI1);

  uint8_t data_received[2];

  twi_package_t packet_read = {

    .addr         = {0b10101101},      // TWI slave memory address data

    .addr_length  = 1,    // TWI slave memory address data size

    .chip         = {0b1000000},      // TWI slave bus address

    .buffer       = data_received,        // transfer data destination buffer

    .length       = 2                    // transfer data size (bytes)

  };

  // Perform a multi-byte read access then check the result.

  const uint8_t test_pattern[] = {0b11100011};

  twi_package_t packet_write = {

    .addr = {0}, // TWI slave memory address data

    .addr_length = 0, // TWI slave memory address data size

    .chip = {0b1000000}, // TWI slave bus address

    .buffer = (void *)test_pattern, // transfer data source buffer

    .length = 1 // transfer data size (bytes)

  };

  while(1){

    pio_set(PIOA, PIO_PA31);

    delay_us(1);

    pio_clear(PIOA, PIO_PA31);

    twi_master_write(TWI1, &packet_write);

    delay_us(20);      

    twi_master_read(TWI1, &packet_read);

    delay_ms(10);

    //twi_master_read(TWI1, &packet_read);

  }

}