I am trying to get a simple SPI transfer working between my host device and an AD9371 on a custom PCB I am working on. Unfortunately, it seems like all my SPI reads return 0x00 (I have verified this with a scope) as if the chip is not responding.
The one thing my "common.c" does differently is that I currently do not toggle RESETB (i.e., CMB_hardReset() is a NOP). I was wondering if that could be the culprit of what I am seeing.
Is the state of the AD9371 different after it is power cycled versus toggling RESETB?
Thanks in advance for the help.
For SPI you can verify if the max speed is within specification. Also you can reduce the SPI rate to see if it works.
Register 0x00A is the scratch pad register. You can write and readback from this register to verify SPI.
It is recommended to toggle the RESET signal after power has stabilized prior to configuration. This will help to get the chip to a known good state.