Atmega 644 mit FTDI 221X über SPI

Hey Guys,

I am trying to connect a FTDI 221X [1][2] (in 1-Bit mode) with an 
Atmmega 644. The Documentation tells me it is "some kind of spi", but I 
am unable to get it running.

My Circuit looks something like that:

1

2

|-------|     |---------------|

3

| _644_ |     | FT221X        |

4

| CLK   |-----| CLK           | 

5

| MOSI  |-----| IO0 (MIOSIO0) |

6

| MISO  |-----| ???           | 

7

|-------|     |---------------|

I have no clue, where to put MISO from Atmega, so I left it unconnected 
(because the "MISO" of FT221X is some kind of state flag)

With this configuration I could send data from 644 over FT221X to USB 
without any problems, but I cannot find circuit and code where I can 
read data from the FT221. I have tested all data Lines with my Oszi and 
tried to see any kind of useful signal - nothing.

If i can help you helping me by providing code or more information - 
just say a word.

Greetings,

Johannes

[1] http://www.ftdichip.com/Products/ICs/FT221X.html
[2] 
http://www.ftdichip.com/Support/Documents/DataSheets/ICs/DS_FT221X.pdf