Tenstorrent has released the open source beta of the Open Chiplet Atlas® (OCA) Harness, a chiplet design framework that turns the OCA interoperability architecture into reusable, deployable implementations.
The OCA Specification defines rules for chiplets from different vendors to work together across the software, system, protocol, transport and physical layers. The Harness builds those rules into infrastructure for security, boot, system management, debug and test, and die-to-die integration. Tenstorrent says chiplet teams using the Harness can lower non-recurring engineering (NRE) costs and integration risk, and spend more time on their application logic.
The beta includes the complete Harness RTL and three management subsystems: the OCA Security Processor (SEP), which provides secure boot, measurement, key management and lifecycle control; the OCA System Management Controller (SMC), which manages system bring-up, clocks, power, thermal, reset coordination and telemetry, and implements OCA-defined boot and configuration protocols used by peer chiplets; and Debug and Test Ports (DTP), which provide uniform cross-chiplet debug and test access, including JTAG and OCA cross-trigger support.
The OCA System Management Unit (SMU) brings the subsystems together, while the OCA AoU implementation carries native AXI4 traffic over UCIe die-to-die links between chiplets. A C++/SystemC virtual platform lets teams begin firmware development before RTL simulation or silicon.
BOS Semiconductors contributed the original AXI over UCIe RTL, and lowRISC helped open source the Harness. VNChip Labs and Signaloid are OCA ecosystem partners with contributions in progress.
Wei-Han Lien, chief CPU architect and senior fellow at Tenstorrent, said: “The OCA architecture gives chiplet designers the freedom to build without depending on a single vendor. The Harness gives teams a reference design that reduces integration complexity so they can focus on their core IP and launch custom silicon.”
Tenstorrent designed the beta for early adopters, integrators and contributors. The full release is targeted for January 2027, and the OCA Harness GitHub repository is the starting point for teams.
