ZCU111 RFSOC PYNQ External clocking ( LMX2594 )

[SimonHildebrand]

Hi,

I am using PYNQ with ZCU111 RFSOC board. I can reprogram the LMX2594 external PLL using the SDK baremetal drivers. However I have never succeeded in progamming the LMX2594 from PYNQ Pyhton drivers. I have taken one the of the standard demo designs and output each of the DAC and ADC clocks from the rf_data_converter IP. I divide the clocks by 16 (using BUFGCE and a flop ) and output the signals via J10 of the extender board. Thus I can “see” the adc and dac clocks. If I try and use the LMX2594 clock configuration routines from the PYNQ library the adc and dac clocks die.

Can anyone advise me on how to fix this?

Thanks
Simon

[SimonHildebrand]

Found problem.

The Zynq Ultrascale+ MPSOc IP runs code to drive the I2C bus which programs the LMX2594 and other clock control devices.

DO NOT FORGET…you need to enable the I2C I/O for the Zynq processor. See the attached image.

Double click on the Zynq IP in the block diagram, then click on one of the I2C blocks in the Re-customize IP pop-up.

Then configure the I2C as per the image.

Note there is no error or warning if you do not do this…and then you cannot program the clocks!!

Enjoy.

[rock]

Awesome. Many PS configurations are not changed after boot, and even after reloading the overlay. pynq at least reconfigures the PL clocks.