Nuclei Eval SoC

Note

Nuclei CPU IP now with iregion feature will use totally new evaluation SoC, this SoC is different from previous Demo SoC, please take care.

Nuclei DemoSoC is now removed in 0.5.0 release, and please use evalsoc now.

Nuclei Eval SoC is an evaluation FPGA SoC from Nuclei for customer to evaluate Nuclei RISC-V Process Core, and it is a successor for Demo SoC.

Overview

To easy user to evaluate Nuclei Processor Core, the prototype SoC (called Nuclei Eval SoC) is provided for evaluation purpose.

This prototype SoC includes:

  • Processor Core, it can be Nuclei N class, NX class or UX class Processor Core.

  • On-Chip SRAMs for instruction and data.

  • The SoC buses.

  • The basic peripherals, such as UART, SPI etc.

With this prototype SoC, user can run simulations, map it into the FPGA board, and run with real embedded application examples.

If you want to learn more about this evaluation SoC, please get the <Nuclei_Eval_SoC_Intro.pdf> from Nuclei.

Supported Boards

In Nuclei SDK, we support the following boards based on Nuclei Evaluation SoC, see:

Usage

Note

To ensure compatibility when using Nuclei EvalSoC(FPGA), please verify with our Application Engineer (AE) the specific CPU configuration to confirm if the EvalSoC’s CPU possesses the features you intend to test. You can utilize the cpuinfo application to determine the available CPU features on your system and cross-reference this information with the Nuclei ISA specifications.

Note

In latest CPU RTL generation flow, it will also generate an Nuclei SDK to match CPU and EvalSoC RTL configuration, please use the generated Nuclei SDK to evaluate your CPU and EvalSoC feature.

The generated Nuclei SDK by nuclei_gen will do the following tasks:

  • Generate SoC/evalsoc/cpufeature.mk: which will define CORE, ARCH_EXT, QEMU_SOCCFG or SIMULATION default value.

  • Generate SoC/evalsoc/Common/Include/cpufeature.h: which will define current cpu feature macros.

  • Generate SoC/evalsoc/evalsoc.json: which will define current qemu soc configuration according to the evalsoc and cpu configuration.

  • Generate SoC/evalsoc/Board/nuclei_fpga_eval/Source/GCC/evalsoc.memory: which will define the ilm/dlm/flash/ddr/sram base address and size.

  • Modify SoC/evalsoc/Board/nuclei_fpga_eval/openocd_evalsoc.cfg: Mainly change workmem_base/workmem_size/flashxip_base/xipnuspi_base to adapt the evalsoc configuration.

If you want to use the generated Nuclei SDK by nuclei_gen In Nuclei Studio IDE, you need to zip it first, and then import it using RV-Tools -> NPK Package Management in Nuclei Studio IDE’s menu, and when creating a IDE project using New Nuclei RISC-V C/C++ Project, please select the correct sdk and version which you can check it in the <SDK>/npk.yml file, and in the project example configuration wizard window, you should configure the Nuclei RISC-V Core and ARCH Extensions, Nuclei Cache Extensions according to your configured CPU ISA, and CPU feature defined in generated cpufeature.h.

WARNING: Currently you still need to modify IAR linker script(*.icf) by yourself, it is not automatically modified.

If you want to use this Nuclei Evaluation SoC in Nuclei SDK, you need to set the SOC Makefile variable to evalsoc.

Extra make variables supported only in this SoC and used internally only by Nuclei, not designed for widely used:

  • RUNMODE: it is used internally by Nuclei, used to control ILM/DLM/ICache/DCache enable or disable via make variable, please check SoC/evalsoc/runmode.mk for details. It is not functional by default, unless you set a non-empty variable to this RUNMODE variable, it can be used with different ILM_EN/DLM_EN/IC_EN/DC_EN/CCM_EN.

  • L2_EN: it is used internally by Nuclei, used to control L2 cache enable or disable, introduced in 0.6.0 release.

  • LDSPEC_EN: it is used internally by Nuclei, used to control load speculative enable or disable, introduced in 0.6.0 release.

  • BPU_EN: it is used internally by Nuclei, used to control branch prediction unit enable or disable, introduced in 0.6.0 release.

  • ECC_EN: it is used internally by Nuclei, used to control (ilm/dlm/L1 I/Dcache)ecc unit enable or disable, introduced in 0.7.0 release.

  • XLCFG_xxx make variables such as XLCFG_CIDU, XLCFG_CCM, XLCFG_TEE and XLCFG_SMPU which are used to overwrite default macros defined in cpufeature.h which will affect XXX_PRESENT macros in evalsoc.h, introduced in 0.7.0 release.

  • CODESIZE: it is used to control whether remove all template routine code for interrupt and exception and banner print code to measure basic code size requirement for evalsoc when CODESIZE=1

  • **SYSCLK``: it is used together with CODESIZE=1 to overwrite default SYSTEM_CLOCK macro value for different bitstream, eg. SYSCLK=50000000 CODESIZE=1, it will set default SYSTEM_CLOCK to 50000000.

  • QEMU_MC_EXTOPT is used to pass extra options to Nuclei Qemu -M machine options for evalsoc, please dont pass any extra , to this make variable, you can pass such as QEMU_MC_EXTOPT=debug=1 but not pass QEMU_MC_EXTOPT=,debug=1

  • QEMU_CPU_EXTOPT is used to pass extra options to Nuclei Qemu -cpu cpu options for evalsoc, please dont pass any extra , to this make variable, you can pass such as QEMU_CPU_EXTOPT=vlen=512 but not pass QEMU_CPU_EXTOPT=,vlen=512

# Choose SoC to be evalsoc
# the following command will build application
# using default evalsoc SoC based board
# defined in Build System and application Makefile
make SOC=evalsoc info # you can check current working SDK configuration information
make SOC=evalsoc clean
make SOC=evalsoc all