// MCTP over I3C
Bring up MCTP
over I3C.
Platform management is moving off SMBus and onto I3C: NVMe-MI, SPDM, and PLDM riding a faster, lower-power bus. Binho gives you the tools to bring it up, decode the full stack, and debug what breaks.
// the transport layer
MCTP standardizes the message. I3C moves it.
The Management Component Transport Protocol (MCTP), defined by the DMTF, standardizes how platform-management messages are structured and addressed. It is deliberately agnostic to what carries them. Increasingly, what carries them is I3C.
Modern platforms manage SSDs, power controllers, temperature sensors, accelerators, and memory modules over one bus. I3C earns that job over legacy SMBus: 12.5 MHz instead of 1 MHz, dynamic address assignment, in-band interrupts without extra wires, and far lower power. MCTP over I3C, the DMTF DSP0233 transport binding, is how NVMe-MI, SPDM, and PLDM reach the devices on the bus.
// the stack
One command rides three layers.
A request starts life as an NVMe-MI command, becomes MCTP packets, and ends up as I3C private writes on the wire. Every layer has to be right for the byte to land.
// application layer
NVMe-MI · SPDM · PLDM
The management payloads themselves: drive health and inventory over NVMe-MI, device attestation over SPDM, firmware and platform management over PLDM. Each is independently versioned.
// message / transport layer
MCTP endpoints and messages
MCTP addresses each device by Endpoint ID, splits messages into packets carrying start / end-of-message flags and sequence numbers, and protects every packet with a CRC-8 PEC. Baseline MTU is 69 bytes: a 4-byte header, 64 bytes of payload, and 1 PEC byte.
// physical transport
The I3C bus
I3C carries MCTP over private writes and reads at up to 12.5 MHz. Devices are discovered by Dynamic Address Assignment and identified as MCTP-capable by DCR 0xCC. A target signals data-ready with an In-Band Interrupt using MDB 0xAE, with no extra wires and far less power than SMBus.
// solutions
See the whole stack. Then drive it.
One tool decodes every layer of MCTP over I3C. The other lets you generate the traffic and reproduce the fault.
Software · Saleae Plugin
I3C Protocol Analyzer Plugin
Every layer of the stack, correlated.
Decodes the I3C bus down to DAA, IBI, and CCC timing, and surfaces the MCTP and NVMe-MI traffic riding on top, inside the Saleae tool your engineers already use. When a command hangs, you can see exactly which layer dropped it.
- I3C timing: DAA, IBI, CCCs, hot-join
- MCTP over I3C and NVMe-MI decode
- Full I3C spec coverage: v1.0, v1.1, v1.1.1, v1.2
Hardware · USB Host Adapter
Binho Supernova
Be the controller, or the endpoint.
The Supernova drives the I3C bus as Controller or Target, fully scriptable from Python and C. Generate MCTP traffic, stand in for an endpoint that isn't built yet, and reproduce the exact fault you're chasing, on the bench or in a regression rig.
- Operates as I3C Controller or Target
- Scriptable traffic via Python & C/C++ SDK
- SDR · HDR-DDR · point-and-click GUI
// our edge
MCTP is only as solid as the I3C beneath it.
We don't watch from the sidelines. Plugfest after plugfest, our team is in the room where vendor I3C implementations come together: finding edge cases, debugging quirks, and validating real silicon against the spec.
// collaborations
Beyond the tools.
Our work lives inside the I3C industry's dev kits, app notes, and demos.
Bundled with the PIC18-Q20 Curiosity Nano.
As an official Microchip Development Tool Partner, we ship our I3C Protocol Analyzer plugin for Saleae Logic with every PIC18-Q20 Curiosity Nano dev kit. Microchip's lowest-cost I3C Target MCU board includes a free 45-day license, bundled directly with the hardware.
Read the announcement
Featured in their I3C application note.
AN5879, "Introduction to I3C for STM32H5 series MCU," is the 64-page document STMicro hands to every developer adopting I3C on STM32. The decoded I3C waveforms throughout the document are captures from our protocol analyzer.
View AN5879 (PDF) Powering their live I3C demo.
Microchip Try runs an interactive I3C session on a real PIC18F16Q20 board, accessible to anyone in the world via the web. Our Supernova USB-to-I3C controller is the device executing every transaction the demo issues.
Try the demo
MEMS sensor evaluation platform.
Our I3C Target Board accessory accepts Bosch's Shuttle 3.0 form-factor and STMicro's DIL24 evaluation boards, the two dominant sockets for I3C-capable sensor prototyping. Drop in your eval board, plug into the Supernova, decode the bus in seconds.
See the I3C Target Board// track record
We've been doing this for years.
Long enough to know where the gotchas live.
// 01 · standards
We help write the spec.
Binho is a MIPI Alliance Contributor Member, actively shaping I3C, the foundation MCTP over I3C is built on.
// 02 · tools
We build the tools.
200+ semiconductor companies use Binho tools to develop, validate, and ship devices with I3C protocol support.
// 03 · plugfests
We prove it in the field.
We've verified our tools at the past 4 MIPI I3C Plugfests, and helped others verify theirs too.
// trusted by engineering teams at
+ hundreds more
Ready to bring up MCTP over I3C?
From first endpoint bring-up to production regression, our I3C team knows where this stack breaks.