We are using the ADRV9371 /ZC706 evaluation platform to play out waveforms through the AD9371. The waveform buffer on the evaluation platform is currently limited to about 4M samples. We have a need for longer waveforms. Our FPGA engineer says the waveform buffer is implemented by a DDR controller which looks like it is programmed to read out buffers of up to 2^24 bytes from the DDR memory. He says it can theoretically programmed in "2D" mode where it can handle N rows of 2^24 bytes.
As the software writer I am not sure where to start. I currently use the IIO library to access this buffer:
- iio_device_create_buffer() to create the buffer
- iio_buffer_first() to get pointers to the start of I and Q channels
- iio_buffer_push() to start playing the waveform out.
This works very well.
How do I get access to lower level devices, drivers or registers to program the DDR controller allow longer buffers?
Or is there another way of achieving what we need?