OCP 3.0 Specification Ready for Review

Open Core Protocol International Partnership (OCP-IP) released the OCP 3.0 specification for member review. The thrid version supports cache coherence, more aggressive power management, an additional high-speed consensus profile, and other new elements. Work on OCP 3.0 was conducted by members of the OCP-IP Specification Working Group including: MIPS Technologies, Nokia, Sonics Inc, Texas Instruments, Toshiba and other industry leading companies.

The extensions in OCP 3.0 differ from traditional coherence approaches by cleanly separating the primitive operations associated with maintaining coherence from the specific system-level approach for implementing the communication and storage aspects of a coherent system. This extends a key advantage of OCP – the ability to develop IP cores independently from the system in which they will be used – into the domain of cache coherent systems. In particular, the OCP coherence extensions have been validated against both invalidate-based snoopy and directory-based coherence schemes.

OCP 3.0 defines a new connection protocol that allows the power management hardware to disconnect the OCP interface without losing any transaction so the manager may then independently shut off power.

A third profile (Profile 3) has been added in OCP 3.0. Profile 1 is a simple slave profile. Profile 2 is a high-speed profile, and Profile 3 is an advanced high-speed profile needed for high speed CPUs, high-performance video graphics accelerators and DRAMS.

More info: OCP-IP