Baochip 1x

This repo contains the open source elements of the Baochip 1x. This repo focuses on the hardware elements of the Baochip 1x.

Developers are referred to the official Rust SDK, located in the Xous repo. There is a vscode extension named baochip which can automate build & flash for officially supported development boards.

Code Organization

• docs contains source for the Baochip 1x book.
• rtl contains the open-sourced elements of the taped out RTL.
• Vexriscv contains the source configuration for the Vex CPU
• scripts contains helper scripts for repo management
• verilate contains the files to simulate a subsetted RTL analog of the Baochip-1x using verilator.
• arty contains the files to build Arty-A7 targeted SoC stubs. Useful for debugging and developing future extensions.

Auto-extracted documentation based on the RTL in this repo have been uploaded to peripherals core cluster.

Releases, tags and branches

This repo revolves around an artifact that is fixed and unpatchable. Therefore, the typical OSS strategy of "just update to HEAD" to simplify release management does not apply.

• Each die rev will get a tag with a name of the form tapeout-a0. This represents the point at which the contents of the rtl directory exactly matches what went into the tapeout.
• A branch is also made with the same name at that time
• The assumed role of the main branch is to evolve the simulation tools and documentation around the rtl artifact. The rtl artifact loses its value if it functionally diverges from what is actually in a chip. Thus, future feature requests and bug fixes must go into a different branch or a fork of the repo.
• It is assumed that die revs, if any, will be limited and rare. main will track the latest die rev, but the previous tapeout-* branches will hold snapshots of the rtl directory as matching the older die rev, allowing users of older die revs to run simulation/docgen tools on the older revisions.

Die rev numbering takes on the form of XY where X is an alphabetic character and Y is a numeric character. The alphabetic character represents a full-mask set; the numeric represents a metal-mask or final-test repair stepping.

Block Diagram