VexRiscv (RV32IM CPU)
VexRiscv is an fpga friendly RISC-V ISA CPU implementation with following features :
RV32IM instruction set
Pipelined on 5 stages (Fetch, Decode, Execute, Memory, WriteBack)
1.44 DMIPS/Mhz when all features are enabled
Optimized for FPGA
Optional MUL/DIV extension
Optional instruction and data caches
Optional MMU
Optional debug extension allowing eclipse debugging via an GDB >> openOCD >> JTAG connection
Optional interrupts and exception handling with the Machine and the User mode from the riscv-privileged-v1.9.1 spec.
Two implementation of shift instructions, Single cycle / shiftNumber cycles
Each stage could have bypass or interlock hazard logic
FreeRTOS port https://github.com/Dolu1990/FreeRTOS-RISCV
Much more information there : https://github.com/SpinalHDL/VexRiscv