Post Go back to editing

AD9082 JESD204C link fails when changing decimation ratio at runtime


I am using the AD9082 in dual link mode. I would like to change the decimation ratio of the FDDC on the fly, without changing the JESD204C data rate. The AD9082 supports this for power of two decimation ratios, as it can repeat samples using the upsampler block. 

My understanding is that I need to set the decimation ratio and the overall decimation ratio using adc_ddc_fine_dcm_set() and adc_ddc_overall_dcm_set() functions.

When doing this, after three or so decimation changes I am seeing the JESD204C link failing, with a failure of sync header and multiblock lock .  (Only the link which has had the decimation ratio changed, not the other link). 

Is this because I cannot tell the AD9082 the overall decimation ratio (so it can configure the upsampler correctly) and change the decimation ratio at the same time?  So I'm guessing the JESD framer over/underflows?

Or, is there some other process or ordering of commands I should be using?

Thanks for the help.