CodeVision AVR: pointer type problem

Error: D:\...\project_sercom.c(639), included from: project_0-1.c: function argument #1 of type 'char' is incompatible with required parameter of type 'char *'

// function call which the error refers to:

CRC_calc(*data_buf0, *datbuf0_cnt);

// the used global char array:

char data_buf0[DATA_BUF0_MAX];

// function:

void CRC_calc(char *data_buf, unsigned char *buf_cnt)

{

  unsigned char i = 0;

  unsigned char local_buf_cnt = 0;

  unsigned int ui_CRC = 0;

  char CRC_ASCII_byte[3] = { 0, 0, 0 };

  local_buf_cnt = *buf_cnt;

  // Calculate 16bit unsigned int CRC

  ui_CRC = ui_CRC ^ address;

  for ( i = 0; i < buf_cnt; i++ )

  {

    ui_CRC = ui_CRC ^ *(data_buf + i);

    if ( ( 0x0001 && ui_CRC ) == 1 ) ui_CRC = ( 0x7FFF & ( ui_CRC >> 1 ) ) ^ 0xA001;

    else ui_CRC = 0x7FFF & ( ui_CRC >> 1 );

  }

  // put CRC into 3 ASCIIs:

  CRC_ASCII_byte[0] = 0x40 | ( 0x000F & ( ui_CRC >> 12 ) );

  CRC_ASCII_byte[1] = 0x40 | ( 0x003F & ( ui_CRC >> 6 ) );

  CRC_ASCII_byte[2] = 0x40 | ( 0x003F & ui_CRC );

  // add the 3 CRC ASCIIs to buffer:

  for( i = 0; i < 3; i++ ) *(data_buf + local_buf_cnt + i) = CRC_ASCII_byte[i];

  *buf_cnt = local_buf_cnt + 3;

}