Industry trade group releases ExpressCard standard

The industry trade group PCMCIA, which maintains the standard for PC cards, has released the ExpressCard standard, which reduces...

The industry trade group PCMCIA, which maintains the standard for PC cards, has released the ExpressCard standard, which reduces the size of the expansion cards and removes legacy bus technology.

Designers are expected to produce the first cards to be tested in early next year, with most cards for notebooks appearing in the second half of 2004, said Brad Saunders, chairman of the board and technical chair of the PCMCIA, and a staff mobile system architect for Intel.

For the standard, the PCMCIA switched to a serial bus from the older peripheral component interconnect parallel bus used by the CardBus standard. This allowed the group to reduce the size of cards based on the standard, which encourages notebook manufacturers to include more than one slot in their designs, he said.

Cards based on the standard will fall into two categories, based on width. Most designs will use the ExpressCard 34 design, which sets the width of cards at 34mm. For some applications, such as Wan cards for GPRS roaming, the wider ExpressCard 54 standard will be used to produce cards that can handle the higher thermal requirements of those applications.

Existing CardBus PC cards are 54mm wide. Most applications do not require a card that large, but the size has endured as a legacy design, Saunders said. Only applications such as the GPRS roaming card require the extra space for heat to dissipate.

The standard also eliminates the need for a host bus controller that required its own chip and electronics to work. By using technologies already built into the chipset, such as PCI Express and USB (universal serial bus), the overall cost of including the ExpressCard technology in a notebook is reduced.

Several companies are lined up to support the standard, including Dell, Hewlett-Packard, IBM, Lexar Media, Microsoft, SCM Microsystems and Texas Instruments.

Tom Krazit writes for IDG News Service

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