When it comes to RISC-V^® customization, most tools on the market rely on manually edited or additionally provided code to the original RTL and tools. This approach is lengthy, unsuitable for flexible changes, and potentially unable to take full advantage of any added custom instructions.

In comparison, Codasip Studio generates all the needed tools and code from the CodAL™ description fully automatically. All the generated parts are new and natively aware of the custom instructions. We don't use intrinsics, and are thus able to compile better performing code.

First of all, we describe the architecture of a RISC-V processor in the CodAL language.

CodAL is a high-level hardware description programming language, developed by Codasip specifically for processor architecture description and modelling.

• Hardware development kit (HDK) = set of tools necessary to simulate, debug, and successfully integrate the processor RTL into a SoC
• Software development kit (SDK) = set of tools necessary to create, simulate, and debug programs for the newly designed processor

The high-level CodAL model can easily reflect any desired custom changes to the processor design. It is especially convenient in case of RISC-V, an architecture that is flexible and customizable by its very design – allowing to add a standard instruction set of your choice, or design a custom one while maintaining compliance with the RISC-V standard.

The CodAL model is used by Codasip Studio to generate the complete customized HDK and SDK.

Off-the-shelf Codasip RISC-V Processors are pre-verified, but a new or customized processor core requires new verification. Codasip Studio generates a full UVM environment ready for verification. The generated simulator serves as a golden Reference Model, the generated RTL running in a RTL simulator servers as design-under-test (DUT), and the UVM-based verification process verifies that their behavior is equivalent.