StarFabric VMEbus board packs dual Motorola processors

This dual-processor XtraPower PPCM2 board from Radstone Embedded Computing is available in a range of ruggedization levels with pricing starting at $10,000. As the company's press statement says, it's a 6U-sized VMEbus board running 7448s. But, the press release does not mention that the 7448 is a member of Motorola's G4+ line of microprocessors. The Moto silicon combines a power-efficient CPU with a megabyte of on-chip L2 cache.

The press statement also briefly refers to the Marvell chip, but it's worth amplifying that statement a bit. The Marvell system controller, a Discovery III device, combines a high bandwidth memory controller, two PCI-x interfaces, and many communications peripherals.

There are no less than a half dozen DMA controllers alone, thanks in part to the Discovery chipset. That means you can efficiently move large blocks of data. As you can surmise, the combination of the Moto processors and the Marvell chipset contributes a great deal to the system's ultra-high performance.

In addition, the featured StarFabric is a switched interconnect technology originally defined by StarGen, a fabless semiconductor company, with the assistance of the StarFabric Working Group.

Used for backplane and chassis-to-chassis applications, the 2.5Gbps scalable StarFabric, as enabled in two channels on the PPCM2, really kicks next-generation embedded distributed processing applications up a notch or two. StarFabric supports multiple classes of traffic, and leverages existing standards-based software and hardware. It should bring a lot to the party in multi-board cardcages.

Error-corrected main memory
The PPCM2's architecture also relies on a large error-corrected main memory array that can be populated with up to 1,024MB of DDR (double data rate SDRAM). The 7448 processor interfaces to this memory across a 64-bit-wide data bus running at 133MHz. The system's flash (anywhere from 128MB to as much as 512MB) talks with the CPU across a 32-bit data bus, also clocking at 133MHz.

Within the flash array's boot area is something called BANC (boot area non-corruptible). The BANC contains a firmware monitor that will re-boot the board if any or all loaded programs are corrupted. That's a nifty reliability feature. Also, the system's non-volatile RAM gives you fast Reads and Writes, but with EPROM non-volatility.

The softer side
On the software side, Radstone's press release notes that the board supports the Wind River's popular VxWorks realtime operating system, as well as LynxOS from LynuxWorks, and Green Hills Software's INTEGRITY.

For its part, the scalable and deterministic VxWorks provides distributed backplane and networking support. You can also use it with lots of third-party wares. VxWorks 6.x includes memory management support, task protection, and enhanced error management. VxWorks 6.x also includes Workbench IDE, a development suite for DSO (device software optimization).

The royalty-free INTEGRITY realtime operating system, from Radstone technology partner Green Hills, uses hardware memory protection to isolate and protect itself—and user tasks—from incorrect operation caused by accidental errors or malicious tampering. Its object-oriented design gives you strict access control and verification of the security and integrity of data, communications, components, and the system.

Linux, of course
Then there's LynxOS support. LynxOS is also a memory-managed realtime operating system, based on Unix. LynxOS conforms to the POSIX standards and features Linux binary compatibility at v4.0 and above.

In addition to LynuxWorks's Board Support Package Radstone provides its Enhanced Support Package for the PPCM2 board. It's a deterministic memory-managed system with protected address spaces for tasks.

It also has a Linux ABI (application binary interface. Linux binaries run unchanged on LynxOS v4.0. You also get POSIX API (application programming interface) conformance 1003.1, .1b and .1c, along with true linear scalability.

On-board testability

The PPCM2 also includes powerful testability features. Test is implemented with what Radstone calls BIT (built-in test), and BCS (background condition screening). BIT is an initialization functional test. Radstone claims BIT gives you 95-percent coverage.

What's more, BIT executes before any operating system, and passes control to the operating system upon completion of its testing. BIT is also a configurable component, with options for individual tests and sub-tests, as well as customization. BIT's test results are stored in flash for later analysis.

For its part in the testability game, BCS provides continuous health monitoring. It runs as a task thread, featuring non-intrusive tests that co-operate with the normal functioning of the operating system. BCS works through operating system mechanisms and doesn't compromise a machine state imposed by the operating system.

- Alex Mendelsohn
eeProductCenter