PCMCIA cards gain PCI Express connection
FEBRUARY 20--The PCMCIA standards group (San Jose, CA) has announced a major makeover for PC plug-in cards, putting them on the PCI Express interconnect. The effort is the first major revision for PC cards in several years and holds the promise of enabling powerful, easy-to-use add-ons for both notebook and desktop computers.
The so-called New Card spec provides a 2.5-Gbit/s Express channel for PC cards that could handle functions like Gigabit Ethernet controllers or IEEE 1394b (FireWire) interfaces. Designers expect to complete the current 0.7 draft specification sometime in the third quarter of this year.
New Card, a temporary placeholder name, defines a card that can use three interconnects--PCI Express, USB 2.0, and the Systems Management Bus (SMBus). Cards have the option of using either the 2.5-Gbit/s Express or the 480-Mbit/s USB bus. The SMBus is a signaling path used for devices to identify themselves in PC systems management applications. A number of companies are expected to announce their support for New Card, including Intel, Microsoft, and Hewlett-Packard.
The specification aims to provide a low-cost transition from today's PCMCIA on several fronts. The New Card spec leverages a new version of the internal mini-PCI card for PCI Express that also uses Express, USB 2.0 and the SMBus and is expected to have a similar form factor. Designers hope OEMs can build one small PC board that could be used in internal mini-PCI Express cards or external New Cards.
The New Card form factor is tentatively set at 34 x 75 x 5 mm for a single-wide version. To accommodate the trend toward thin notebooks, the group also has specified a double-wide card, aiming at long New Cards rather than today's deep PCMCIA cards. Nevertheless, designers believe OEMs could use a single systems case design to accommodate either PCMCIA or New Card slots.
Finally, by tapping existing Express and USB interconnects, designers expect that engineers can deliver New Cards with existing silicon blocks. Today's PCMCIA cards are based on the 32-bitm 33-MHz Cardbus, a unique PCMCIA bus.
Engineers involved in the New Card effort said they foresee use of the cards for new high-end add-ons in both notebooks and desktops. That could help breathe new life into the PCMCIA market that has been stagnant as functions such as 10/100-Mbit Ethernet and modems have moved to the motherboard.