STM32 USB TCPM Software Eases Migration to USB-PD 3.0 Power Delivery
Article By : STMicroelectronics
Fully certified two-chip solution includes port controller
Geneva, June 12, 2018 — Helping engineers leverage the latest USB Power Delivery capabilities and versatile USB Type-C™ connections in new or legacy product designs, STMicroelectronics has introduced new software for implementing a Type-C Port Manager (TCPM) on any general-purpose STM32* microcontroller.
Compliant with the USB Type-C Port Controller Interface (TCPCi) specification, and designed to manage a separate single- or multi-port Type-C Port Controller (TCPC) chip, ST’s X-CUBE-USB-PD stack implements the protocol layer and policy engine of the USB Power Delivery Specification (USB-PD 3.0 v1.1). The stack demands minimal STM32 resources, having a low memory footprint and using only a single I2C bus address and one alert pin per port. In addition, standard register maps ensure easy interoperability with any connected TCPC device.
X-CUBE-USB-PD supports all USB-PD 3.0 options, including Programmable Power Supply (PPS) for connecting fast chargers, Fast Role Swap (FRS) for seamless user experiences during cable insertion or removal, and authentication-message exchange to allow data or power transfer only with genuine devices or chargers.
By supporting Provider, Consumer, and Dual-Role (DRP) modes, the stack enables product designers to leverage the benefits of USB Type-C in a wide variety of equipment types, such as power hubs or power banks, docking stations, game controllers, PC peripherals, multi-function accessories, and small appliances such as cordless vacuum cleaners, portable speakers, lighting products, proprietary chargers, and many other applications.
ST has tested the stack with ON Semiconductor’s FUSB307B, a USB-PD 3.0 v1.1-certified TCPC chip, creating a fully certified and ready-to-use solution that centralizes the TCPM for multiple USB-PD ports. The FUSB307B provides a 1Mbps I2C microcontroller interface and handles functionality such as plug-insertion/orientation detection and dead-battery power-up. Time-critical Power-Delivery functions that offload the microcontroller effectively enable any STM32 including entry-level devices to manage multi-port, multi-role USB-PD interfaces. X-CUBE-USB-PD currently contains libraries tested on STM32 Arm® Cortex®-M0 and Cortex-M4 microcontrollers, giving developers a choice of over 420 different part numbers. Libraries for other STM32 series will be introduced by the end of 2018.