FrontPanel AXI okHost lets a host program access your FPGA design using standard AXI. okHost carries standard AXI Manager and Subordinate interfaces, and your design provides the matching endpoints. okHost is the gateware half of the link; on the host side you write a program against the FrontPanel API, documented separately in the FrontPanel SDK. These pages explain how to connect okHost, build it into your design, and simulate it. The FrontPanel API calls you make on hardware are the same calls the simulation bus functional model (BFM) mirrors, so a design checked in simulation behaves the same on the board.

These pages assume the AXI specification. okHost is standard AXI, and this documentation is a thin layer over the AMBA AXI specification. It states only what is specific to okHost: the optional signals it omits, the sideband constants it drives, and the behaviors outside the specification, such as its operation timeout. It has no signal descriptions and no timing diagrams. For the protocol itself, refer to the Arm AMBA specifications.

okHost presents the same AXI contract over any host transport. A transport can add behaviors of its own that surface at okHost, documented on the transport’s own page.

• Interoperable with any AXI IP. okHost presents standard AXI, so it works with any AMD or third-party AXI IP. → okHost Core
• Built-in operation timeout. okHost bounds every operation with a timeout and returns the partial counts, so a stalled, buggy, or non-compliant Subordinate cannot hang the host. → Error Handling
• Debug from the returned counts. Every data-moving operation returns a byte count. AXI-Full and bulk AXI-Lite writes also return a transaction count, and both counts are partial on a timeout. → Counts Returned
• Per-interface resets. Three independent active-low resets that also serve as the recovery path. → Resets
• Behavioral simulation without hardware. The BFM reproduces okHost’s documented behavior. → The BFM Behavioral Contract

These pages apply to Opal Kelly’s FrontPanel-AXI boards (“AXI boards”), as distinct from the FrontPanel Classic boards. If you are moving a design from FrontPanel Classic, see the Migration Guide. The interfaces, the BFM behaviors, and the build flow are common across the AXI-board family. The supported AXI boards are:

• SZG-HUB1450-AU10P

Ready to get okHost onto your board? See Getting Started, the step-by-step tutorial.