InterChip USB


InterChip USB is an addendum to the USB Implementer Forum's USB 2.0 specification. The USB 3.0 successor of HSIC is called SuperSpeed Inter-Chip.
IC-USB is intended as a low-power variant of the standard physical USB interface, intended for direct chip-to-chip communications. The IC-USB bus's maximum length of 10 cm results in a lower inductance and capacitance and therefore allows lower power requirements.
IC-USB is being used primarily in embedded systems and standards. One of the most relevant areas of application is in mobile phones, where, for instance, ETSI has standardized on IC-USB as the official high-speed interface for connections between the phone's main chipset and the SIM card or UICC card.
USB 2.0 High-Speed Inter-Chip is a chip-to-chip variant of USB 2.0 that eliminates the conventional analog transceivers found in normal USB. It was adopted as a standard by the USB Implementers Forum in 2007. The HSIC physical layer uses about 50% less power and 75% less board area compared to traditional USB 2.0. HSIC uses two signals at 1.2 V and has a throughput of 480 Mbit/s. Maximum PCB trace length for HSIC is 10 cm. It does not have low enough latency to support RAM sharing between two chips.

History

The forum's Inter-Chip USB Supplement was released in March 2006. ETSI TS 102 600, which is ETSI's USB implementation requirements specification, was first released in December 2007.