problem with SPI & MAX6662 (at89s8252)

I have problem with implementing MAX6662 chip. I have already interfaced ds1306 rtc with 3wire serial interface and it works. The problem is that the max6662 uses non usual spi interface. There are no mosi/miso pin instead of this there is one bi-directional pin DQ for data transfers. Can this chip be interfaced to this microcontroller ? How to do that (mayby use tri-state buffer's) ? For first i connected mosi and miso line from uC together and use this code:

void spi_wr(unsigned char d)
{
   SPDR = d;
   while ((SPSR & 0x80) == 0)
      ;
}

unsigned char spi_rd(void)
{
   unsigned char v;
   SPDR = 0xFF;
   while ((SPSR & 0x80) == 0)
      ;
   v    = SPDR;
   return (v)
}

And the code for gathering temp:

  ...
  CS = 0;
  spi_wr(0xC1);
  hi = spi_rd();
  lo = spi_rd();
  CS = 1;
  ...

This is not working. Second problem is that ds1306 uses two data lines and do not respond when lines is connected with each other.

Is there work around ? Or somebody know some spi temp. chip with normal spi interface ?

sorry for my broken
English
Lukasz Bajger