The ExpressLane PEX 8619, PEX 8615 and PEX 8609 PCIe Gen 2-compliant switches are available to enhance system performance by improving current DMA usage and offering additional cost savings by eliminating DMA burden from processors and/or endpoints.

The DMA engine in the company’s new devices can also be utilized to perform multicast function. The advantages for implementing the DMA-based multicast scheme incorporate support for unlimited number of multicast groups, each descriptor ring represents a multicast group, a reliable multicast scheme, status for each copy made can be offered by a DMA engine, that multicast transfers are not limited to the posted transactions, and most significantly, DMA-based multicast from the company offers a PCIe multicast solution.

The addition of multicast in the new PCIe devices is being addressed within the PCI Special Interest Group (PCI-SIG) in the form of an engineering change notice (ECN) to the PCIe 2.0 specification. The ECN describes function of the multicast, which allows the new PCIe switch to send a single packet to many destinations concurrently, thus significantly decreasing latency and increasing the effective throughput of a system.

Processor and chipset makers have been implementing DMA as part of their efforts to increase system performance for years in markets such as embedded control planes, enterprise storage and computing, stated Sergis Mushell, principal research analyst, Gartner Research. Dynamic memory access technology has proven itself and the integrated PLX solution within the PCI Express switch should find wide acceptance in the design community.

Using the DMA engine in the PLX PCI Express switch provides an efficient and attractive alternative to implementing multicast until the multicast function becomes natively available in ramping PCIe switches, stated Krishna Mallampati, director of PCIe switch marketing, PLX. The multicast function described in the ECN can be implemented today using the DMA engines available in PLX’s industry-first PCI Express switches with integrated DMA.

Pricing and Availability:

The PEX 8619, PEX 8615 and PEX 8609 are sampling with volume prices at $28.55, $22.25 and $14.25, respectively. The company’s PCIe switches offer board and system designers with the broad and proven lineup of products ranging in the density from three to 16 ports and from four to 48 lanes.