Example Programs There are two example programs for the FFT application; one uses the ARM CPU & NEON co-processor to perform the FFT calculation, and the other uses the FFT hardware in the FPGA. There are many more variants of these examples, using different data sizes, and data sources (FFT RAM vs. CPU cache) in the src directory. There are also scripts for generating waveform plots of from the results data if you wish to experiment further.

neon32_256.c

This program performs the FFT operation using the ARM CPU and NEON co-processor using data stored on the SD Card.

ffftdma_256.c

This program performs the FFT operation using the hardware accelerator and DMAs inside the FPGA using data stored on the SD Card. The input and output data pass through the Acceleration Coherency Port (ACP) of the processor's L2 cache.

Please see the README files in the sandbox directory for more information.

Tutorials

The README_SANDBOX.txt file contains detailed instructions. scripts and functions for interacting with the board.

If you are using SSH, it is handy to have two terminals open to the same example directory. Display the README file in one terminal (e.g. cat readme_sandbox.txt) Copy the example scripts from this terminal and paste into the second terminal as you progress through the tutorial.

If you are using a VNC client: Open the README file with gedit. Open a terminal window and navigate to the example directory. Copy scripts from gedit and paste into the terminal window.

Build Scripts and Related C code Scripts are provided to build the applications, generate sample data, and prepare results to be displayed using tools like GNU Plot.

Building the applications

• sandbox_build_all.sh
• target_build_app.sh
• target_build_lib.sh
• target_build_ne10.sh
• clean_all.sh

Generate Sample Data

• sandbox_create_input_waveforms.sh
• create_real_short_sine32.c
• create_real_short_square32.c
• create_real_short_triangle32.c
• duplicate_x8.sh
• real_short_to_ne10cpx_long.c
• real_short_to_ne10cpx_short.c

Prepare Results For Display

• ne10cpx_long_to_text.c

Sandbox Directory The sandbox directory contains source files, scripts and documentation you can review, run, modify, and recompile as you wish. It also contains a tar ball which is a copy of the entire sandbox contents so they can be restored if needed.

/examples/fft
├── bin
│   ├── fft.tgz
│   ├── README_TARGET.TXT
│   └── setup_target_fft_env.sh
├── sandbox
│   ├── clean_all.sh
│   ├── COPYING
│   ├── create_real_short_sine32.c
│   ├── create_real_short_square32.c
│   ├── create_real_short_triangle32.c
│   ├── duplicate_x8.sh
│   ├── fftdma_256.c
│   ├── ne10cpx_long_to_text.c
│   ├── Ne10-master.zip
│   ├── neon32_256.c
│   ├── overhead.c
│   ├── README_SANDBOX_BUILD.TXT
│   ├── README_SANDBOX.TXT
│   ├── real_short_to_ne10cpx_long.c
│   ├── real_short_to_ne10cpx_short.c
│   ├── sandbox_build_all.sh
│   ├── sandbox_create_input_waveforms.sh
│   ├── target_build_app.sh
│   ├── target_build_lib.sh
│   └── target_build_ne10.sh
├── src
│   ├── images
│   │   ├── create_gnuplot_sine_256.gnu
│   │   ├── create_gnuplot_sine_256x32.gnu
│   │   ├── create_gnuplot_sine_4096.gnu
│   │   ├── create_gnuplot_squares_256.gnu
│   │   ├── create_gnuplot_squares_256x32.gnu
│   │   ├── create_gnuplot_squares_4096.gnu
│   │   ├── create_gnuplot_triangle_256.gnu
│   │   ├── create_gnuplot_triangle_256x32.gnu
│   │   ├── create_gnuplot_triangle_4096.gnu
│   │   ├── create_montage_sine_256.sh
│   │   ├── create_montage_sine_256x32.sh
│   │   ├── create_montage_sine_4096.sh
│   │   ├── create_montage_squares_256.sh
│   │   ├── create_montage_squares_256x32.sh
│   │   ├── create_montage_squares_4096.sh
│   │   ├── create_montage_triangle_256.sh
│   │   ├── create_montage_triangle_256x32.sh
│   │   └── create_montage_triangle_4096.sh
│   ├── archive_for_target.sh
│   ├── c16_256.c
│   ├── c16_256x32.c
│   ├── c16_256x32x128.c
│   ├── c16_4096.c
│   ├── c32_256.c
│   ├── c32_256x32.c
│   ├── c32_256x32x128.c
│   ├── c32_4096.c
│   ├── clean_all.sh
│   ├── COPYING
│   ├── create_input_waveforms.sh
│   ├── create_real_short_sine32.c
│   ├── create_real_short_square32.c
│   ├── create_real_short_triangle32.c
│   ├── duplicate_x128.sh
│   ├── duplicate_x32.sh
│   ├── duplicate_x8.sh
│   ├── fft_256.c
│   ├── fft_256x32.c
│   ├── fft_256x32x128.c
│   ├── fft_4096.c
│   ├── fftdma_256.c
│   ├── fftdma_256x32.c
│   ├── fftdma_256x32x128.c
│   ├── fftdma_4096.c
│   ├── ne10cpx_long_to_text.c
│   ├── ne10cpx_short_to_text.c
│   ├── Ne10-master.zip
│   ├── neon16_256.c
│   ├── neon16_256x32.c
│   ├── neon16_256x32x128.c
│   ├── neon16_4096.c
│   ├── neon32_256.c
│   ├── neon32_256x32.c
│   ├── neon32_256x32x128.c
│   ├── neon32_4096.c
│   ├── overhead.c
│   ├── README_TARGET_BUILD.TXT
│   ├── README_TARGET.TXT
│   ├── real_short_to_ne10cpx_long.c
│   ├── real_short_to_ne10cpx_short.c
│   ├── run_all.sh
│   ├── run_fft_256.sh
│   ├── run_fft_256x32.sh
│   ├── run_fft_256x32x128.sh
│   ├── run_fft_4096.sh
│   ├── run_stream_256x32x128.sh
│   ├── setup_target_fft_env.sh
│   ├── stream_fpga_256x32x128.c
│   ├── stream_neon32_256x32x128.c
│   ├── stream_raw_256x32x128.c
│   ├── target_build_all.sh
│   ├── target_build_app.sh
│   ├── target_build_lib.sh
│   └── target_build_ne10.sh
├── fft_sandbox.tgz
└── fft_src.tgz