xdma_stream

Innova2 XCKU15P XDMA to AXI4-Stream Demo

PCIe XDMA to AXI4-Stream demo for the Innova-2 using Vivado 2022.2 with Floating-Point and AXI-Lite to BRAM and GPIO.

Block Design

Bitstream

Download the demo bitstream and load it into your Innova-2. It should work with every variant of the Innova-2. Refer to innova2_flex_xcku15p_notes for system setup.

wget https://github.com/mwrnd/innova2_experiments/releases/download/v0.1.1-alpha/innova2_xdma_stream_demo.zip
md5sum innova2_xdma_stream_demo.zip
echo 4fe405753b00b895fc8858996d40eb2c should be the MD5 Checksum
unzip -d . innova2_xdma_stream_demo.zip
md5sum *bin
echo 3685651141d715af32902520add8d529 is the MD5 checksum of innova2_xdma_stream_demo_primary.bin
echo 5bf29940319ba46a6206a8c8807b06bf is the MD5 checksum of innova2_xdma_stream_demo_secondary.bin

AXI Addresses

Testing

Correct Data Transfer Test

Confirm data transfers correctly using dd. Note interface set _1 is set up as a loopback.

In one terminal window generate some data and send it to the file that the XDMA Driver creates for the AXI4-Stream Host-to-Card (H2C) interface.

dd if=/dev/urandom bs=8192 count=8192 of=TEST
sudo dd if=TEST of=/dev/xdma0_h2c_1 count=8192 bs=8192

In a second terminal window, read data from the file that the XDMA Driver creates for the AXI4-Stream Card-to-Host (C2H) interface and check the read and written data is identical.

sudo dd if=/dev/xdma0_c2h_1 of=RECV count=8192 bs=8192
md5sum TEST RECV

Experiment with different count= and bs= (Block Size) values. The maximum throughput depends on the speed of your disk drive as the data is being written from and to files. The H2C throughput will be slower as it includes the time it takes you to switch to the second window and start the second dd.

Data Throughput Tests

By using /dev/zero as the source of data and /dev/null as the sink you can experiment with data throughput vs. count= and bs= (Block Size) values.

In one terminal:

sudo dd if=/dev/zero of=/dev/xdma0_h2c_1 count=32768 bs=16384

In a second terminal:

sudo dd if=/dev/xdma0_c2h_1 of=/dev/null count=32768 bs=16384

The H2C throughput will be slower as it includes the time it takes you to switch to the second window and start the second dd.

Testing the Floating-Point Block

Interface set _0 is connected to a Floating-Point Block that multiplies its inputs. Each input is the same so it is calculating a square of the input.

Compile and run the streamtest.c demo. Note DATA_SIZE must be at least 32 which is the width of the AXI4-Stream Interface, 256bits=32bytes. The demo runs square-root on the received data to confirm it was squared correctly.

gcc -Wall streamtest.c -o streamtest -lm
sudo ./streamtest

Testing the BRAM and GPIO over AXI-Lite

TODO

I synthesized and implemented the design with the address space set to 1Mbyte.

This does not allow access to half the BRAM and the GPIO Block as the BRAM alone is 2Mbytes.

This can be fixed by increasing the AXI-Lite Address Space to 4Mbyte and moving the GPIO Block to something within that range, like 0x300000.

Recreating the Design

Download innova2_xdma_stream.tcl and constraints.xdc and source the Tcl script in Vivado 2022.2.

pwd
cd DOWNLOAD_DIRECTORY
source -verbose innova2_xdma_stream.tcl