AD7176 Problem SPI Communication

Hi,

I tried to to test the SPI communication (clock 4MHz) between an ATmega8 and an AD7176. Therefor I send to the AD 0x47 to read the ID register.  With an logic analyzer I see that the AD do not respond to my command

I look the MISO signal with the Oscilloscope and it seem that the signal is not stable!

I don't know what to do to establish the communication, or is my AD the problem?

I really need your help!

Thanks a lot

David