Here we will describe how to run the nmsis dsp examples in Nuclei Spike.


  • Nuclei Modified Spike - xl_spike

  • Nuclei SDK modified for xl_spike branch dev_xlspike

  • Nuclei RISCV GNU Toolchain

  • CMake >= 3.5

Tool Setup

  1. Export PATH correctly for xl_spike and riscv-nuclei-elf-gcc

export PATH=/path/to/xl_spike/bin:/path/to/riscv-nuclei-elf-gcc/bin/:$PATH

Build NMSIS DSP Library

  1. Download or clone NMSIS source code into NMSIS directory.

  2. cd to NMSIS/NMSIS/ directory

  3. Build NMSIS DSP library using make gen_dsp_lib

  4. Strip debug informations using make strip_dsp_lib to make the generated library smaller

  5. The dsp library will be generated into ./Library/DSP/GCC folder

  6. The dsp libraries will be look like this:

$ ll Library/DSP/GCC/
total 28604
-rw-r--r-- 1 hqfang nucleisys 1847080 Jul 14 14:51 libnmsis_dsp_rv32imac.a
-rw-r--r-- 1 hqfang nucleisys 2515912 Jul 14 14:51 libnmsis_dsp_rv32imacp.a
-rw-r--r-- 1 hqfang nucleisys 1786008 Jul 14 14:51 libnmsis_dsp_rv32imafc.a
-rw-r--r-- 1 hqfang nucleisys 2377420 Jul 14 14:51 libnmsis_dsp_rv32imafcp.a
-rw-r--r-- 1 hqfang nucleisys 1785500 Jul 14 14:51 libnmsis_dsp_rv32imafdc.a
-rw-r--r-- 1 hqfang nucleisys 2367840 Jul 14 14:51 libnmsis_dsp_rv32imafdcp.a
-rw-r--r-- 1 hqfang nucleisys 2374468 Jul 14 14:51 libnmsis_dsp_rv64imac.a
-rw-r--r-- 1 hqfang nucleisys 3369340 Jul 14 14:51 libnmsis_dsp_rv64imacp.a
-rw-r--r-- 1 hqfang nucleisys 2276836 Jul 14 14:51 libnmsis_dsp_rv64imafc.a
-rw-r--r-- 1 hqfang nucleisys 3151172 Jul 14 14:51 libnmsis_dsp_rv64imafcp.a
-rw-r--r-- 1 hqfang nucleisys 2275828 Jul 14 14:51 libnmsis_dsp_rv64imafdc.a
-rw-r--r-- 1 hqfang nucleisys 3140188 Jul 14 14:51 libnmsis_dsp_rv64imafdcp.a
  1. library name with extra p is build with RISCV DSP enabled.

    • libnmsis_dsp_rv32imac.a: Build for RISCV_ARCH=rv32imac without DSP enabled.

    • libnmsis_dsp_rv32imacp.a: Build for RISCV_ARCH=rv32imac with DSP enabled.


  • You can also directly build both DSP and NN library using make gen

  • You can strip the generated DSP and NN library using make strip

How to run

  1. Set environment variables NUCLEI_SDK_ROOT and NUCLEI_SDK_NMSIS, and set Nuclei SDK SoC to xlspike

export NUCLEI_SDK_ROOT=/path/to/nuclei_sdk
export SOC=xlspike
  1. Let us take ./riscv_class_marks_example/ for example

  2. cd ./riscv_class_marks_example/

  3. Run with RISCV DSP enabled NMSIS-DSP library for CORE n307

# Clean project
make DSP_ENABLE=ON CORE=n307 clean
# Build project
make DSP_ENABLE=ON CORE=n307 all
# Run application using xl_spike
make DSP_ENABLE=ON CORE=n307 run
  1. Run with RISCV DSP disabled NMSIS-DSP library for CORE n307

make DSP_ENABLE=OFF CORE=n307 clean
make DSP_ENABLE=OFF CORE=n307 all
make DSP_ENABLE=OFF CORE=n307 run


  • You can easily run this example in your hardware, if you have enough memory to run it, just modify the SOC to the one your are using in step 1.