ethernet-dm8806

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目前產品有使用Ethernet Switch DM8806，了解一下datasheet

更新記錄

item note
20160624 第一版

目錄

DM8806

DAVICOM

  • 聯傑國際(DAVICOM Semiconductor, Inc.)成立於1996年，由聯華電子網路通訊團隊與美國網通專家所組成
  • 嵌入式高速乙太網路通訊晶片系列
  • Embedded Ethernet Controller
  • NIC/ Non-PCI
    • DM9000
    • 32-bit 10/100M Ethernet controller with processor interface.
    • DM9000A
    • 16-bit 10/100M Ethernet controller with processor interface.
  • Switch/ MII
    • DM8806
    • 6-Port Fast Ethernet Switch Controller.
    • Supports 5TP & MII,RMII,IEEE802.3az,

DM8806

  • 來源-mdio rgmii mac phy简单了解
  • 对于MII接口，IEEE 802.3标准描述PHY用于向MAC提供TX和RX时钟
    • 在MAC到MAC应用中，这将意味着需要使用外部电路来产生这些时钟
  • 卓联公司通过使交换机的MAC产生这些时钟，解决了这一问题，消除了对附加电路的需要
    • 该接口称为Reverse MII(RvMII)

  • reverse MII is the name for a reverse loop of data,來源-What is Reverse MII in Ethernet interface

  • dm8806 block

[dm8806]
  • Network Interface / Pin Define
pin type note
P0_TX -/+ I/O Port 0 TP TX
P0_RX -/+ I/O Port 0 TP RX
P1_TX -/+ I/O Port 1 TP TX
P1_RX -/+ I/O Port 1 TP RX
P2_TX -/+ I/O Port 2 TP TX
P2_RX -/+ I/O Port 2 TP RX
P3_TX -/+ I/O Port 3 TP TX
P3_RX -/+ I/O Port 3 TP RX
BEGRES I/O Bandgap pin
VCNTL I/O 1.8V
VRET O Voltage Reference
  • Port4 MAC MII Pins
pin type note
P4M_TXD3,2,1,0 O Transmit Data (bit 3-0)
P4M_TXE O Transmit Enable
P4M_TXC I Trasmit Clock
P4M_CRS I Carrier Sense
P4M_COL I Collision Detect
P4M_RXC I Receive Clock
P4M_RXDV I Receive Data Valid
P4M_RXD3,2,10 I Receive Data (bit 3-0)

  • Port4 MAC Reverse (RevMII)

  • MII本來傳送輸要MAC輸出TXC(Clock),RevMII則不需要由MAC來提供Clock

pin type note
P4M_TXD3,2,1,0 O Transmit Data (bit 3-0)
P4M_TXE O Transmit Enable
P4M_TXC O Trasmit Clock
P4M_CRS O Carrier Sense
P4M_COL O Collision Detect
P4M_RXC I Receive Clock
P4M_RXDV I Receive Data Valid
P4M_RXD3,2,10 I Receive Data (bit 3-0)
  • Port4 MAC Reduce MII (RMII) Pins
pin type note
P4M_TXD1,0 O Transmit Data
P4M_TXE O Transmit Enable
P4M_REFCLK_O O Reference Clock 50Mhz Output
P4M_REFCLK_I I Receive Clock 50MHz Input
P4M_CRSDV I Receive Data Valid
P4M_RXD1,0 I Receive Data

  • MII共需要14條訊息號線, RMII少了txd3-2,rxd3-2,P4M_CRS,P4M_COL共少了6條訊號線-

  • MII /RMII

[tlk110]

MDI-II / MDI-X

  • 自動分辨網路線跳線或平行線 (Auto MDI/MDIX),來源- 基礎網路概念]
  • MDI (for medium dependent interface),
    • media attachment unit (MAU)
    • The MDI is the componet of the MAU that provides the physical and electrical connection to the cabling medium
    • 即為一般的網路線(pin1-8 是對接到 pin1-8),用來連接PC及switch
  • MDIX
    • An MDIX (for MDI crossover) is a version of MDI that enables connection between like devices
    • 即為網路線跳線

參考來源