PCMCIA cards gain PCI Express connection
By Rick Merritt, EE Times
February 19, 2003 (5:13 p.m. EST)
SAN JOSE, Calif. The PCMCIA standards group will announce a major makeover for PC plug-in cards on Wednesday (Feb. 19), 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/second Express channel for PC cards that could handle functions like Gigabit Ethernet controllers or 1394b 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 system s management applications.
A number of companies are expected to announce their support for New Card on Wednesday at the Intel Developer Forum, 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.
Mini-PCI cards are often used in notebooks for features an OEM does not want to put on a motherboard, such as modems that may vary depending on a geographic market.
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 engineers can deliver New Cards with existing silicon blocks. Today's PCMCIA cards are based on the 32-bit 33-MHz Cardbus, a unique PCMCIA bus.
One unique development with New Card is its connector. Rather than a traditional pin-and-socket connector, New Card uses what has been referred to as a beam-and-blade approach with "feelers" that surround pc-board contacts.
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.
Dell Computer Corp. has shown concept computers using PCI Express modules to create plug-and-play C PU, graphics and other core modules.