We’ve recently added complete USB C® port support in the TrueTask® USB / MCCI USB DataPump® portable USB host/device software platform.
Here are some of the key features:
- Explicit finite state machines that are identical to the FSMs in the USB Type C Cable and Connector Specification Revision 2.0. Why? It makes it much easier to debug systems if you can refer back to the canonical specification. Interesting because? Many port controllers, including those based TCPC, incorporate parts of the canonical FSM in their own function. It’s tempting to elide the standard state transitions, but this makes problems much harder to debug, because you can’t refer back to the specification.
- TCPC separated from Type-C FSM. Why? Type C and TCPC are different specs, and keeping them separate makes it easier to correlate code to the relevant spec. Interesting because? The TCPC spec doesn’t really have this concept of separation; see previous point. Further, there’s no requirement to conform to TCPC in implementations; by keeping TCPC separate, we can easily implement drivers for different port-controller models.
- TCPC implementation separated from register access mechanism TCPC can be implemented with direct register accesses or via serial register access busses such as I2C or SPI. This complicates abstraction a lot, if you’re designing a software package to operate in environments from bare iron to sophisticated kernel environments like Windows or Linux. MCCI uses a micro-VM to handle register accesses, which conveniently hides all the details from the TCPC driver.
- Ready for USB Power Delivery. PD depends very much on the Type-C implementation. Our architecture explicitly allows for activating (and deactivating) PD behavior at the appropriate moments in the Type-C FSMs.
Interested in embedded USB Type C support? Mail us at email@example.com, and our engineers will help understand all the options.