原标题：Microchip LAN9355全特性3端口以太网交换方案

　　microchip公司的LAN9355是集成了双路MII/RMII/Turbo MII的高性能小占位面积的3端口10/100以太网交换,支持IEEE 1588v2,网络速率高达200Mbps,适合用于消费类电子,嵌入使和工业电子产品.本文介绍了LAN9355主要亮点,框图,电源连接图,评估板EVB-LAN9353主要特性,框图,电路图和材料清单.

　　Microchip’s LAN9355/LAN9355i is a high-performance, small-footprint, full-featured 3-port managed Ethernet switch. This device is application-optimized for consumer, embedded and Industrial electronic designs which require a highly integrated, cost effective device with switching functionality, flexibility and ease of integration.

　　Featuring the industry’s smallest form factor 3-port switch, the LAN9355/9355i supports compact PCB design and MII/RMII/Turbo MII (Media Independent, Reduced Media Independent and Turbo Media Independent Interfaces). This device supports Turbo MII mode to accomplish network speeds up to 200 Mbps. The virtual PHY feature mimics a single PHY connection through the MII/RMII/Turbo MII interface to the host SoC, which can reduce software development time. This feature also allows system designers to swap the single PHY and Ethernet switch to create multiple SKUs from the same software driver.

　　IEEE 1588v2 is supported via the integrated IEEE 1588v2 hardware time stamp unit, which supports end-to-end and peer-to-peer transparent clocks. The LAN9354 complies with the IEEE 802.3 (full/half-duplex 10BASE-T and 100BASE-TX) Ethernet protocol, IEEE 802.3az Energy Efficient Ethernet (EEE) (100Mbps only), and 802.1D/802.1Q network management protocol specifications, enabling compatibility with industry standard Ethernet and Fast Ethernet applications. 100BASE-FX is supported via an external fiber transceiver.

　　The LAN9355/9355i switch combines all of the functions of a 10/100 system, including the switch fabric, packet buffers, buffer management, MACs, PHY transceivers and optional serial management functions. Both devices comply with IEEE 802.3 10BASE-T and 100BASE-TX Ethernet protocol specifications, enabling compatibility with industry standard Ethernet and Fast Ethernet applications. Supports Fiber Interface through SFP and SFF Physical medium

　　Microchip’s complimentary and confidential LANCheck® online design review service is available for customers who have selected our products for their application design-in.The LANCheck online design review service is subject to Microchip’s Program Terms and Conditions and requires a myMicrochip account.

　　LAN9355主要亮点:

　　IEEE 1588-2008 hardware time stamping unit

　　IEEE 802.3az Energy Efficient Ethernet

　　Wake On LAN

　　Cable Diagnostics

　　High-performance, full-featured 3-port switches with per-port IEEE 802.1Q VLAN support (up to 16 VLAN groups) test

　　IGMP v1/v2 monitoring for multicast packet filtering

　　Up to 200 Mbps network speed via a Turbo MII interface

　　Optional EEPROM or external CPU serial management support via an I2C™ interface

　　Virtual PHY feature simplifies softwar development by mimicking multiple switch ports as a single-port PHY

　　Integrated regulators require a single 3.3V supply

　　42 per-port MIB counters for efficient network management

　　Supports Fiber Interface through SFP and SFF Physical medium

　　Industrial temperature (-40°to 85°C) options available (LAN9353i)

　　Package options:

　　LAN9355: 12x12mm, 88-pin QFN package for dual MII/RMII/Turbo MII

　　LAN9355: 12x12mm, 80-pin VTQFP-EP package for dual MII/RMII/Turbo MII

　　LAN9355目标应用:

　　Cable, Satellite, and IP Set-top Boxes (STBs)

　　Digital Televisions (DTVs)

　　Digital/Personal Video Recorders (DVRs/PVRs)

　　VoIP/Video Phone Systems

　　Home Gateways/Consumer Audio/Video

　　Security and Surveillance

　　Building Automation

　　Test/Measurement Equipment

　　Industrial Automation and Control

　　图1.LAN9355框图

　　图2.LAN9355电源连接图:调节器使能

　　图3.LAN9355电源连接图:调节器禁用

　　评估板EVB-LAN9353

　　The EVB-LAN9353 is an Evaluation Board (EVB) that utilizes the LAN9353 to providea fully-functional three-port Ethernet switch with Single MII/RMII/Turbo MII or DualRMII. The EVB-LAN9353 provides one fully integrated MAC/PHY internet port (Port 2)via on-board RJ45 connectors. Port 0 and Port 1 provides two MII port connectorswhich support the following:

　　• An external “Dual RMII –Capable or singleMII / RMII / Turbo MII”-Capable MAC(with LAN9353 in PHY mode), via the on-board 40-pin male MII connector

　　• An external “Dual RMII –Capable or singleMII / RMII / Turbo MII”-Capable PHY(with LAN9353 in MAC mode), via the on-board 40-pin female MII connector

　　Power is supplied to the board via a +5V external wall mount power supply.

　　The EVB-LAN9353 includes a 64K x 8 I2C EEPROM that may be used to automaticallyload configuration settings from the EEPROM into the device at reset. An I2C hostadapter interface header (10-pin, 2x5) is provided to simplify I2C based configuration.

　　A simplified block diagram of the EVB LAN9353 can be seen in Error! Referencesource not found and LAN9353 supports for CONFIG 9 or CONFIG 10.

　　CONFIG 9: used to configure the LAN9353 in Dual RMII mode for external ports.

　　CONFIG 10: used to configure the LAN9353 in Single MII/RMII/TMII mode for externalport.

　　图4.评估板EVB-LAN9353外形图

　　评估板EVB-LAN9353材料清单: