We are having problems programming an AD9609 A to D converter. We need set the clock divider to divide by two, but this isn't happening. We take the CSB pin low and then program the registers. Does this pin have to stay low to stop the chip reverting to non- SPI mode. Also, does the chip need reseting at power up using the SPI port?
Thanks for your interest in AD9609.
The CSB pin going high takes the part out of SPI mode so you do need to have CSB low for SPI communication.
The AD9609 does not need SPI resetting at power up.
AN-877 http://www.analog.com/media/en/technical-documentation/application-notes/56755538964965031881813AN_877.pdf has general information on SPI communication with AD9609. Details specific to the AD9609 are in the ADC datasheet.