Editing ISO/IEC 7816 (section)

== 7816-12 Cards with contacts &mdash; USB electrical interface and operating procedures ==

Created in 2005.<ref>{{cite web|url=https://www.iso.org/standard/40604.html |title=ISO/IEC 7816-12:2005 Identification cards — Integrated circuit cards — Part 12: Cards with contacts — USB electrical interface and operating procedures |publisher=Iso.org |date=2011-03-17 |access-date=2017-10-11}}</ref>

According to its abstract, it specifies the operating conditions of an integrated circuit card that provides a [[USB]] interface. An integrated circuit card with a USB interface is named USB-ICC.

ISO/IEC 7816-12:2005 specifies:
* the electrical conditions when a USB-ICC is operated by an interface device – for those contact fields that are not used, when the USB interface is applied;
* the USB standard descriptors and the USB-ICC class specific descriptor;
* the data transfer between host and USB-ICC using bulk transfers or control transfers;
* the control transfers which allow two different protocols named version A and version B;
* the (optional) interrupt transfers to indicate asynchronous events;
* status and error conditions.

ISO/IEC 7816-12:2005 provides two protocols for control transfers. This is to support the protocol T=0 (version A) or to use the transfer on [[Smart card application protocol data unit|APDU]] level (version B). ISO/IEC 7816-12:2005 provides the state diagrams for the USB-ICC for each of the transfers (bulk transfers, control transfers version A and version B). Examples of possible sequences which the USB-ICC must be able to handle are given in an informative annex.

The USB [[Integrated Circuit Card Interface Device|CCID]] device class defines a standard for communicating with ISO/IEC 7816 smart cards over USB.