RISC-V VHDL: System-on-Chip  2.0
RISC-V Processor


Current repository supports two synthesizable processors: Rocket and River. Both of them implement open RISC-V ISA. To select what processor to use there's special generic parameter:


Rocket CPU

Rocket is the 64-bits single issue, in-order processor developed in Berkley and shared as the sources writen on SCALA language. It uses specally developed library Chisel to generate Verilog implementation from SCALA sources.

Rocket Core usually implements all features of the latest ISA specification, either as multi-core support with L2-cache implementation and many other. But it has a set of disadvantages: bad integration with other devices not writen on SCALA, not very-good integration with RTL simulators, no reference model. It shows worse performance than RIVER CPU (for now).

River CPU

River is my implementation of RISC-V ISA writen on VHDL either as all others parts of shared SoC implementation. There's also availabel precise SystemC model integrated into Simulator which is used as a stimulus during RTL simulation and garantee consistency of functional and SystemC models either as RTL.

River CPU is the 5-stage processor with the classical pipeline structure:

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