⇡ Untethered lowRISC tutorial

Overview of the Rocket chip

An overview of Berkeley’s RISC-V “Rocket Chip” SoC Generator can be found here.

A high-level view of the untethered Rocket chip is shown below. The design contains multiple Rocket tiles each of which consists of a Rocket core and L1 instruction and data caches. All tiles share a unified and banked L2 cache and an I/O bus. The Rocket (Chisel) side of the SoC is encapsulated in a Chisel island whose features are configurable using the top-level configuration file $TOP/src/main/scala/Configs.scala (see Configuration parameters for more details). Two NASTI/NASTI-Lite interfaces are exposed to the FPGA peripherals. They implement a limited subset of the AXI/AXI-Lite bus functions. The NASTI interface is used by the L2 cache for memory reads and writes, while the NASTI-Lite interface is used by the I/O bus for peripheral accesses. The NASTI on-chip interconnects are implemented in parameterized SystemVerilog located in $TOP/socip/nasti.


Further reading