switching to DMA Mode from the boot SD card

Just to back up a bit — you are trying to turn on the DMA path in the mux (which is connected to your IP, not actual DMA) or you are trying to use a DMA buffer?

Hi

I have built a DUT in Simulink with MathWorks help.  They and me need the output of this to route to the DAQ2 such that the signals appear on the outputs of that card.   Travis (ADI) was helping us over a year ago, and gave the above instructions which don't appear to work.  If I run a MathWorks script, then I can switch to DMA mode (as opposed to DDS) and my signals appear.  However, as soon as I disconnect that PC (running MATLAB) it switches back to DDS after a delay.  I need to boot into DMA such that my signals are routed to the DAQ always without any MATLAB connection.  I believe there is a multiplexer switch controlled by registers that selects the DAQ2 signal source.  The question is really how do I control that switch within the BOOT process from a SD card exactly?

Many thanks

Philip

Hi

I have built a DUT in Simulink with MathWorks help.  They and me need the output of this to route to the DAQ2 such that the signals appear on the outputs of that card.   Travis (ADI) was helping us over a year ago, and gave the above instructions which don't appear to work.  If I run a MathWorks script, then I can switch to DMA mode (as opposed to DDS) and my signals appear.  However, as soon as I disconnect that PC (running MATLAB) it switches back to DDS after a delay.  I need to boot into DMA such that my signals are routed to the DAQ always without any MATLAB connection.  I believe there is a multiplexer switch controlled by registers that selects the DAQ2 signal source.  The question is really how do I control that switch within the BOOT process from a SD card exactly?

Many thanks

Philip

What happens when you set those registers to 0x2 after you are back in DDS mode?

-Travis

Hi Travis,

When connected to Matlab, I can change between DDS and DMA as often as required by running a script.  I cannot see the exact workings of this at register level as the code is hidden.

Commands at the Linux level or in the SD card do not appear to do anything (other that I can change the amplitude of the DDS signal) with regards to DDS and DMA switching.

For a test with R&S, I need the PC disconnected hence the problem.

Many thanks

Philip

You need to use the offset address of 0x80000000 otherwise you are accessing registers on the DAC and not on the FPGA.

 iio_reg axi-ad9144-hpc $((0x80000418 + i * 0x40)) 0x02

-Travis

Yes this worked thank you