SaxonSoc VS rocket-chip

Most of them might still be missing on the ASIC side, but already exist to some extent on the FPGA side. Litex (https://github.com/enjoy-digital/litex/) is adding support for the USB host (ohci-compatible) developed for Saxon (https://github.com/SpinalHDL/SaxonSoc), in addition to the DRAM, Ethernet (MII, GMII, some RGMII), micro-sd, UART, HDMI framebuffer, ... peripherals that are already supported.

Hello. I'm looking into implementing RISC-V on an FPGA for a school project. The two repos I'm looking into using are the Ariane and RocketChip repos. Both look actively maintained, but RocketChip has more recent releases, and it's used by this other repo that creates a block design in Vivado with the RISC-V RTL. However, we would also like to be able to make changes to the core, and I'm afraid that scala/Chisel might be difficult to learn. Ariane looks like SystemVerilog while RocketChip is mostly Chisel. Does any have recommendations on which RISC-V repo would be good to use for a project?

You could do a trial build of an in-order Rocket RISC-V core [1] to see how much space it takes up.

[1] https://github.com/chipsalliance/rocket-chip

My definition of a RISC CPU is one that has a reduced instruction set. In other words, the category of CPU is defined by the size of the instruction set, not in how it is implemented. Consider for example RISC-V CPUs. These are defined by their open instruction set alone, in spite of the fact that many implementations of RISC-V CPUs exist: some pipelined, and some not.

More complex CPUs are typically completely out of scope for hand coding, therefore you can implement generators like: https://github.com/chipsalliance/rocket-chip

We don't have Sifive's specifically but we do have the open source cores they've historically used to design their cores: https://github.com/riscv-boom/riscv-boom https://github.com/chipsalliance/rocket-chip

This would allow you to experiment with your own chip or something like [the RocketChip generator](https://github.com/chipsalliance/rocket-chip).

https://github.com/chipsalliance/rocket-chip/blob/c7da610430f51b02ebda37f3d444674dc8f2adbf/src/main/scala/system/Configs.scala#L28

You should start tracing through the code to see what that requirement means. Grep through the github repo for things like "rowBits", which brings up this issue (https://github.com/chipsalliance/rocket-chip/issues/1352) which may be relevant to your interests.