Интерфейс ExpressCard: Спецификации и характеристики карт расширения.

Specification for expansion and memory cards

ExpressCard, initially called NEWCARD, is an interface to connect peripheral devices to a computer, usually a laptop computer. The ExpressCard technical standard specifies the design of slots built into the computer and of expansion cards to insert in the slots. The cards contain electronic circuits and sometimes connectors for external devices. The ExpressCard standard replaces the PC Card (also known as PCMCIA) standards. ExpressCards can connect a variety of devices to a computer including mobile broadband modems (sometimes called connect cards), IEEE 1394 (FireWire) connectors, USB connectors, Ethernet network ports, Serial ATA storage devices, solid state drives, external enclosures for desktop size PCI Express graphics cards and other peripheral devices, wireless network interface controllers (NIC), TV tuner cards, Common Access Card (CAC) readers, and sound cards.

Originally developed by the Personal Computer Memory Card International Association (PCMCIA), the ExpressCard standard is maintained by the USB Implementers Forum (USB IF). The host device supports PCI Express, USB 2.0 (including Hi Speed), and USB 3.0 (SuperSpeed) (ExpressCard 2.0 only) connectivity through the ExpressCard slot; cards can be designed to use any of these modes. The cards are hot pluggable. The ExpressCard standard is an open standard by ITU T definition, and can be obtained from the USB IF website free of charge. USB IF administers the ExpressCard Compliance Program, under which companies earn the right to obtain a license to use the ExpressCard logo on their compliant products.

The ExpressCard standard specifies two form factors, ExpressCard/34 ( wide) and ExpressCard/54 ( wide, in an L shape)—the connector is the same on both (34 mm wide). Standard cards are long ( shorter than CardBus) and thick, but may be thicker on sections that extend outside the standard form for antennas, sockets, etc. With its 75 mm standard length, the ExpressCard will protrude 5 mm over the holder's surface (e. g. laptop surface), whereas a variant with 70 mm length remains level with the surface.

The older PC Cards came in 16 bit and the later 32 bit CardBus designs. The major benefit of the ExpressCard over the PC card is more bandwidth, due to the ExpressCard's direct connection to the system bus over a PCI Express ×1 lane and USB 2.0, while CardBus cards only interface with PCI. The ExpressCard has a maximum throughput of 2.5 Gbit/s through PCI Express and 480 Mbit/s through USB 2.0 dedicated for each slot, while all CardBus and PCI devices connected to a computer usually share a total 1.06 Gbit/s bandwidth. The ExpressCard standard specifies voltages of either 1.5 V or 3.3 V; CardBus slots can use 3.3 V or 5.0 V. The ExpressCard FAQ claims lower cost, better scalability, and better integration with motherboard chipset technology than Cardbus. PCMCIA devices can be connected to an ExpressCard slot via an adapter. When the PC Card was introduced, the only other way to connect peripherals to a laptop computer was via RS 232 and parallel ports of limited performance, so it was widely adopted for many peripherals. More recently, virtually all laptop equipment has 480 Mbit/s Hi Speed USB 2.0 ports, and most types of peripheral which formerly used a PC Card connection are available for USB or are built in, making the ExpressCard less necessary than the PC Card was in its day. Some laptop computers do not have an ExpressCard slot.

The ExpressCard 2.0 standard was introduced on March 4, 2009, at CeBIT in Hannover. It provides a single PCIe 1.0 2.5 GT/s lane (optionally PCIe 2.0 with 5 GT/s) and a USB 3.0 "SuperSpeed" link with a raw transfer speed of 5 Gbit/s (effective transfer speed up to 400 MB/s). It is forward and backward compatible with earlier ExpressCard modules and slots. USB 3.0 SuperSpeed compatibility is achieved by sharing the pins with the PCIe link. An inserted card signals which mode should be used. The standard failed to gain widespread use and some Taiwanese manufacturers discontinued it as early as 2011. After the dissolution of the PCMCIA in 2010, the specification, associated documentation and licensing responsibilities were moved to the USB Implementers Forum. The specifications were last revised in 2009, and removed from their website in 2018.