The Wishbone SoC Interconnect Architecture

Wishbone is an interconnect for Systems-on-Chip. It's been placed in the public domain and is (as far as we know) free from patents and royalties. Wishbone is widely used in free and open source designs, but it can also be used in commercial designs without limitations.

Stable specifications

Today, the most used versions of Wishbone are revision B.3, and to a lesser extend, revision B.4. Revision B.4 most notably adds support for pipelining more efficient access to high-latency peripherals like DRAM.

Note: Version B.4 adds new features which are not as widely accepted as the functionality of the previous versions. A future version of the specification will try to reach wider agreement in this regard.

Upcoming Specifications and Contributing

Currently, the B3.1 specification is discussed. It is a minor revision to the B3 spec with clarifications. There will be another major specification process starting soon. You can contribute to the spec via our GitHub repository.

Find the current state here: pdf html

The primary author and maintainer of the Wishbone specification is Richard Herveille. The specification is now developed by a group of people hosted by the FOSSi Foundation. Please join the mailing list (subscribe) if you have questions or want to contribute to the specification process.

Superseeded Specifications

The following specification documents have been replaced by newer versions and should not be used for new designs any more.