Ltc2439-1 in SPI communication data output is high first out or low first out?

Looking at the timing diagram of Figure 3a, I think there could be something wrong with your communication with the ADC. The first two bits should always be zeros. Can you provide an oscilloscope photo showing CSL, SCK, SDI and SDO? A schematic of your circuit would also be helpful.

Thank you for your reply. This problem has been bothering me for a long time. Could you please provide relevant reading and writing routines for ltc2439-1?

This is a relatively old device. I do not have code examples for you. If you look at some of the newer devices that have Linduino support you can find code examples.

This is a relatively old device. I do not have code examples for you. If you look at some of the newer devices that have Linduino support you can find code examples.