Running ResNet-50 on FPGA with Gemmini SoC

systolic-array

We have successfully built a DNN system using the DNN accelerator Gemmini and the RISC-V CPU Rocket on a Digilent FPGA board and run ResNet-50.

Gemmini

Gemmini is one of the RTL generators included in Chipyard, an agile RISC-V SoC design framework, and can generate a systolic array based DNN accelerator.

You can build a DNN hardware platform by combining RISC-V CPU Rocket or BOOM with Gemmini, as described in the README.md in the Gemmini repository below.

The Gemmini project is developing a full-system, full-stack DNN hardware exploration and evaluation platform.

Gemmini SoC for Nexys Video

We have created an SoC that combines a Gemmini and a Rocket for the Digilent FPGA board, a Nexys Video.

The figure below quoted from the Gemmini repository gives an overview of the Gemmini SoC.

gemmini-system

The cycle accurate simulator using Verilator introduced in the previous article is difficult to execute such as ResNet-50 with many cycles, but it can be executed on the FPGA board.

Running Test Programs on FPGA

We loaded the SoC gateware on the FPGA board and ran ResNet-50 and MobileNet included in the test program gemmini-rocc-tests.

ResNet-50

The following shows the console output when running resnet50-linux.

# ./resnet50-linux
...
Prediction: 75 (score: 45)
Prediction: 900 (score: 43)
Prediction: 641 (score: 40)
Prediction: 897 (score: 57)

Total cycles: 1358733049 (100%)
Matmul cycles: 508263409 (37%)
Im2col cycles: 0 (0%)
Conv cycles: 818013564 (60%)
Pooling cycles: 0 (0%)
Depthwise convolution cycles: 0 (0%)
Res add cycles: 32258198 (2%)
Other cycles: 197878 (0%)
PASS

MobileNet

The following shows the console output when running mobilenet-linux.

# ./mobilenet-linux
...
Prediction: 75 (score: 127)
Prediction: 900 (score: 127)
Prediction: 125 (score: 103)
Prediction: 897 (score: 98)

Total cycles: 1045338662 (100%)
Matmul cycles: 89629901 (8%)
Im2col cycles: 0 (0%)
Conv cycles: 7498801 (0%)
Pooling cycles: 0 (0%)
Depthwise convolution cycles: 943204581 (90%)
Res add cycles: 1936088 (0%)
Other cycles: 3069291 (0%)
PASS

Summary

We have successfully built a DNN system using Gemmini and Rocket on Digilent’s Nexys Video and run ResNet-50 and MobileNet included in the test program gemmini-rocc-tests.