Review

Compact PCI, VMEbus, and PMC Boards come in a variety of flavors, such as single-board computers and data acquistion boards, and target a wide variety of applications, such as communications and test. And as ICs become more powerful, particularly microprocessors, so do the boards. The boards also benefit from new technologies, such as packet switching backplanes, Infiniband, and so forth. This year produced many advances among these products. Some examples follow.

Communication applications converging on packet-based architectures were the target of the Katana3750 CompactPCI packet switching backplane (cPSB) processing blade from Artesyn Communications (artesyncp.com). Employing three 800-MHz PowerPC 750FX processors, the blade triples the processing power in the same space as traditional CPU boards. It is compliant with PICMG 2.16 cPSB specs and includes a local GbE switch that automatically routes IP traffic to the appropriate processor for core on-card communication.

VMIC's (vmic.com) VMICPCI-5800 single-slot, cPCI InfiniBand-based CompactPCI-to-CompactPCI bridge made it possible to extend a traditional system's expansion capability beyond a single chassis. The card allows a single host controller to transparently access other cPCI devices in multiple cPCI chassis. Transparent PCI-to-PCI bridging requires a minimum of two VMICPCI-5800 cards; one configured as the master and the other as a slave.

For applications requiring many a/d conversions, Acromag's (acromag. com) APC341 (PCI) and AcPC341 (cPCI) analog input boards employ eight 14-bit A/D converters to perform simultaneous a/d conversions and provide 16 differential input channels with a ±10 Vdc range. Their inputs are configured in two eight-channel banks and scan time for each a/d converter is 8 µs or 125 kHz. When scanning eight channels simultaneously, the boards can sample one million channels per second for an overall throughput rate of 1 MHz.

Harnessing the power of four MPC7410 PowerPC processors, Pentek's (pentek.com) Model 4295 VME-bus board gives users greater I/O options via a velocity interface mezzanine (VIM) site and a PMC site. The VIM provides a buffered I/O port for digital receivers and wide-bandwidth data acquisition, while the PMC allows access to a range of industry-standard I/O functions from third-party sources.

Opening the door for further applications, Concurrent Technologies (gocct.com) extended the operating temperature range of its VP 110/010 VME-based, intelligent dual PMC host I/O board to −25°C to +70°C. The board supports an 800 MHz Pentium III processor with 512 KB of cache and provides 512 MB of 133 MHz ECC SDRAM, upgradeable to 1 GB. I/O features include two 64-bit/66-MHz PMC sites and a connector that supports an optional PMC carrier board for expansion to a total of four PMC modules.

To keep things running smoothly, the Vanguard Networked Bus Analyzers from Vmetro (vmetro.com) debug, test, and validate next-generation PCI, PMC, and CompactPCI architectures with full PCI-X support. Armed with a state analyzer, exerciser, statistics, protocol checker, and compliance checker, the analyzers operate through Ethernet or USB interfaces from a PC with Windows running BusView software.

The Palomar 500 PCI mezzanine card (PMC) from SBS Technologies (sbs.com) set up shop in edge and enterprise level communications systems. The card packs a 750CXe PowerPC operating at 133 MHz with a 400 MHz core and its speed can be reduced to 100 MHz with a 300 MHz core to decrease power consumption. A 144-pin SO-DIMM socket supports laptop-style SDRAM modules ranging in density from 64 to 512 MB. Other features include the GT64260B system controller that serves as a PCI bridge from the processor to the PCI bus and host board and as a CPU bus interface, memory controller, Ethernet controller, and an RS-232 serial controller. Other features of the PMC include 4, 8 or 16 MB of Strataflash memory, two RS-232 channels, and one 10/100 Ethernet interface.

—Mat Dirjish

Outlook

Three Amigos
In the late 1990s, there was a word-of-mouth consensus that the VMEbus would fade away in favor of its somewhat less expensive, hot-swap derivative, CompactPCI. There was also some buzz that the PMC would overtake the PCI interface. Apparently, in 2003, that's not the case.

Companies with heavy investments in VME mainframes are not going to switch platforms overnight and most of their applications may not require hot-swap capabilities. Most cPCI systems were startup systems and their users have no need to change. And, since PMC caters to both, all three platforms should share both a secure and very lucrative future.

—MD