TX data format


#1

Hi,

I am using myriad-rf with LMS6002D chip, together with the zipper board and an altera FPGA.

I see there is a 12 bit databus, with a qsel signal to indicate if the data is Q or I. According to the ADC spec I see this data must be on 2’s-complement form.
I am trying to test this by sending two constant values (one for Q and another for I continuously), to see if I have set up the registers correctly. Should this type of simple setup work?
So far it does not seem to work. At least I am not able to measure anything on the X4 connector om myriad board.
What I am trying to do is to send sensor data collected by the FPGA. Can I send “raw” sensor data as I/Q signals or do I have to do some kind of encoding first?

Thanks,
Tom


#2

Hi Tom,

May i know these few things from your settings?

  • what is your baseband bandwidth set to
  • TX_CLK and TX_IQSEL frequency

I am currently trying to do the same thing as you are doing, with:

  • bandwidth: 0.75MHz
  • TX_CLK: 4MHz
  • TX_IQSEL: 2MHz
  • TX_CLK and TX_IQSEL are phase offset properly as timing diagram stated.
  • Hard and soft TX enable are both set.
  • PLL set, calibrations are all done.

However, I am getting the same thing as you where I can’t measure anything on X4 connector.

Do you mind sharing your development on this?

Thank you.