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| Zarlink's ZL33020 Embedded Ethernet Switch Zarlink Semiconductor has expanded its DirectConnect family of embedded Ethernet switches with a new high-capacity aggregation and switch device that simplifies the design of high- density media processing, data plane and control plane cards used in wired, wireless and cable networks. The ZL33020 embedded Ethernet switch is a 24 FE (Fast Ethernet) + 4 GE (Gigabit Ethernet) port device with 3.75 Mbits (480 Kbytes) of embedded memory for control databases and frame data buffer. The device supports multiple interface options, including SMII, RMII, GMII, TBI and MII, enabling designers to easily match a range of Ethernet interfaces available in complementary Ethernet devices. Due to its wide availability, in recent years Ethernet has proven to be an efficient interface for connectivity between DSPs (digital signal processors), micro-controllers and NPUs (network processor units), in applications where heavy data traffic volume must be quickly processed and managed, including modem pools in wireless base stations, VoIP gateways, cable head-end modulators for IP video, high-end traffic management and control plane cards. Most basic Ethernet switches for enterprise applications require external devices that draw from system resources and lock designers into a specific logic. For example, basic Ethernet switches with embedded PHYs (physical interfaces) require additional external PHYs to interface with the DSP, micro- controllers and NPUs. Previous-generation Ethernet switches used in VoIP applications may also require additional FPGAs (field programmable gate arrays) to map voice, fax or general streaming media traffic to the various DSPs used in the board. With the launch of the ZL33020 embedded switch, Zarlink's DirectConnect product family provides a complete offering in embedded device solutions for FE and GE inter-processor connectivity. The DirectConnect portfolio, which also includes the ZL50400/2/4/5/7/8/9 and ZL50410/1 embedded switch families, allows Zarlink customers to chose from a wide variety of FE and GE port count configurations supporting industrial temperature range, an essential requirement in carrier-grade networking. Systems performing heavy media processing functions, such as modem base- band processing, echo cancellation, voice processing, compression, fax processing, radio modulation as well as intense traffic management and control plane functions, employ several DSP/NPU and micro-processor devices to simultaneously manage all transactions at full wire-speed. To maximize the use of bandwidth and avoid any traffic over-flow in the system, a robust bandwidth allocation and buffer management scheme is required when interconnecting all these devices. The ZL33020 switch integrates flexible packet scheduling algorithms and buffer management functions. Designers can use the ZL33020 device to assign packets to four transmission classes on FE ports (eight classes for GE ports) and two levels of dropping precedence. Each packet is assigned a transmission priority and dropping precedence based on user-defined attributes. When interconnecting multiple DSP/NPU devices in a cluster, the ZL33020 switch can implement packet addressing based on MAC Address, Ethernet Type and VLAN Identifier plus packet prioritization based on IEEE 802.1p priority, VLAN Tag, L3 DS/TOS field, IP Type of Service and Layer 4 logical port numbers. This flexible addressing allows system designers to maximize and split media processing resource allocation between DSP and NPU devices in the cluster. Two types of flow control are available in the ZL33020. In half-duplex mode, all ports support backpressure flow control to minimize the effects of lost data during long traffic activity bursts. In full-duplex mode, IEEE 802.3x flow control is provided. write your comments about the article :: © 2006 Networking News :: home page |