PCI Express train rolls across multiple tracks
 

San Jose — At its annual conference here (June 6-7), the PCI Special Interest Group detailed updates and extensions to the PCI Express specification that could drive annual silicon updates through 2007.
The group also discussed plans for using Express over cables and in specialty modules for RF and server subsystems.

The SIG outlined six new directions for Express, taking the serial technology into areas such as security and virtualization. While Express has gained huge mind share with designers, its roll out has been somewhat slower than originally anticipated, said Al Yanes, president of the PCI SIG and a senior ASIC designer at IBM Corp.

"I would have expected to see more Express parts out there by now," said Yanes, who was an early proponent of the PCI-X technology that was once a competitor to Express. He attributed the somewhat sluggish rollout to the tech industry downturn, a lack of compelling applications for the 2.5-GHz data rate of Express and the normal design challenges of leaping from MHz- to GHz-class designs.

The PCI SIG officially announced work on a Trusted Configuration Space addition to the existing Express 1.0a specification. The addition will extend to suitably modified Express I/O devices the root of trust security defined by the Trusted Computing Group.

The spec requires Express root, switch or end-device chips implementing the security scheme to support new trusted read and write commands and watch for a new security flag that triggers access to a secure execution space in memory. The spec is now in review and due to be complete later this summer as part of the Express version 1.1

"This does require hardware changes" for vendors who want to support the optional security features, said Tony Pierce, chairman of the PCI SIG.

An even bigger shift is in the works for the first half of next year when the SIG is expected to complete its version 2.0 spec which boosts data rates from 2.5 to 5 GHz. For backwards compatibility, version 2.0 lets devices automatically negotiate to either version 1.0 or 2.0 data rates. It also includes expanded error reporting and an ability to make adjustments for faults in real time.

The SIG also announced plans to extend the Express spec for virtualized I/O. The extension will allow multiple operating systems to access the same physical I/O resources either simultaneously or in serial fashion. The spec will define supersets for accessing I/O in a single or in a multihost environment.

Software virtualization is seen as a key technique for making best use of the multicore, multithreaded processors beginning to proliferate in the PC market. Advanced Micro Devices and Intel are rolling out separate techniques for virtualizing their multicore processors. With the new spec, the SIG will extend those capabilities to Express-based I/O devices.

more @ http://www.eet.com/news/latest/showA...leID=164300950