AD9633 SPI problem

Hi,

I am trying to communicate with the AD9633 on the EVAL-AD9633. I basically plugged in the board and connected an external SPI master to the USB_SDI, USB_SCLK, USB_CSB and ISB_SDO pins.

Using the recommeded jumper connection on J302 (1-2, 4-5 and 8-9) and then thus feed SPI into the AD9633. I am using a clock frequency as low as 100kHz.

However, I fail to receive any communication reply from the device.

Please see the screenshot in the attachment, for an image where I try to read out register 0x01. On the third byte, I expect the device to reply 0x90, but instead, I receive 0x00 all the time.
Puple: CSB measured on DUT_CSB (on J302)
Yellow: SDIO (measured on DUT_SDIO (on J302)
Blue: SCK (measured on DUT_SCK) (on J302).

Any idea what I could be doing wrong?

Thanks for your reply.

Arnout