Aging algorithms | Texas Instruments TNETX4090 manual

TNETX4090

ThunderSWITCH II 9-PORT 100-/1000-MBIT/S ETHERNET SWITCH

SPWS044E ± DECEMBER 1997 ± REVISED AUGUST 1999

aging algorithms

time-threshold aging

When learning addresses, the IALE adds the address to the table and tags it with a time stamp. If another frame is received with this address, the time stamp is refreshed. If the aging counter expires before another frame is received from this source address, the address is deleted from the table. If the table is full, the oldest address is deleted to make room for a new address, even if the age for this address has not expired.

table-full aging

In table-full aging, the oldest address (or one of the oldest addresses if there is more than one) automatically is deleted from the IALE records only if the table is full, and a new address must be added to the table. In this mode, the age stamp for the addresses is not refreshed.

frame-routing determination

When a frame is received, its 48-bit destination and source addresses are extracted and the VLAN index is determined as described in VLAN Support. The destination address and VLAN index are then looked up in the IALE records to determine if they exist. If a match is found, the information associated with the record is passed on to the frame-routing algorithm. Figure 11 provides a flow diagram of the routing algorithm. For details of the register information referred to in Figure 11, see the TNETX4090 Programmer's Reference Guide, literature number SPAU003.

The source address and VLAN index combination also are looked up in the IALE records to determine if they exist. If a match is found, additional information is provided to the routing process (for details see the TNETX4090 Programmer's Reference Guide, literature number SPAU003).

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Texas Instruments TNETX4090 specifications Aging algorithms

Contents

Description MAC Eeprom CPU I/F MIIMAC MII DMA PCS Duplex LED Rdram Interface Jtag Interface GGP Package Bottom View Signal-to-Ball Mapping Signal Names Sorted Alphabetically Signal Ball Name Reset Sdma SAD0 Control logic interface Terminal FunctionsJtag interface Terminal Internal Description Name RESISTOR² 100-/1000-Mbit/s MAC interface Gmii mode M08TXD7 M08TXD6 M08TXD5 Terminal Internal Description Name Resistor Port to not support pause frames 10-/100-Mbit/s MAC interface MII mode ports 0±7 Pulldown M00RENEG M01RENEG ThunderSWITCH II 9-PORT 100-/1000-MBIT/S ETHERNET Switch M04TCLK M05TCLK M06TCLK M07TCLK AD4 MII management interface Rdram interface DIO interface Eeprom interface 100-/1000-Mbit/s port PCS LED interface Power supplyLED interface Byte DIO Address DIO interface descriptionDIO Internal Register Address Map ThunderSWITCH II 9-PORT 100-/1000-MBIT/S ETHERNET TNETX4090 VLAN1QID VLAN0QID VLAN37QID VLAN36QID TNETX4090 PCS8Status PCS8Control 0x0700 DIO interface description Port no Head Statistic Even ODD Ports Port StatisticsTail Port no Head Statistic Tail 0x90Ex Address-Lookup Statistics DMA Interface SignalsSignal Description Receiving/transmitting management frames DIO Interface State During Hardware Reset State of DIO signal terminals during hardware resetDIO Interface During Hardware Reset Ieee Std 802.1Q Vlan tags on the NM port Tpid TCI Vlan IDFCS CRC TNETX4090 NM bandwidth and priority PHY management interfaceFull-duplex NM port Interrupt processing MAC interface Backoff Adaptive performance optimization APOInterframe gap enforcement Receive versus transmit priority 10-/100-Mbit/s MII ports 0±7 Speed, duplex, and flow-control negotiation 100-Mbit/s Port Negotiation With the TNETE2104 100-/1000-Mbit/s PHY interface port Full-duplex hardware flow control Port 8 Duplex Negotiation in MII ModePort 8 Pause Negotiation in MII Mode Outcome M08GTCLK M08TXEN Pretagging and extended port awarenessPretag on transmission Learning Format Receive Pretag Bit Definitions Transmit Pretag Bit DefinitionsPretag on reception BIT Name Function RXD Flow COL TXD Directed Format Receive Pretag Bit DefinitionsRing-cascade topology TNETX4090 RXD Flow COL TXD M08GTCLK M08TXEN M08RXDV Switch TerminalRing-Topology Connectivity GND SCL SDAEdio TNETX4090 Eclk Summary of Eeprom load outcomes Outcome Stop Load Initd ² Fault LED EclkInteraction of Eeprom load with the SIO register Collision LED States Compatibility with future device revisionsPort LED States State Display Lamp test PCS duplex LEDLED Status Bit Definitions and Shift Order Multi-LED display TNETX4090 VCC NC Txclk Vref Rxclk VDD BUS Enable GND BUS Ctrl Rdram SINBUS Enable GND Rdram BUS Ctrl SIN Sout SCHAIN0 Txclk Vref Rxclk VDD Racbist instruction Jtag Instruction OpcodesHighz instruction Jtag Bist Status Iale Frame routingVlan support Ieee Std 802.1Q header ± transmission Address maintenanceIeee Std 802.1Q tags ± reception Spanning-tree support Aging algorithms Frame-Routing Algorithm SPWS044E ± December 1997 ± Revised August Port routing code Port trunking/load sharing Removal of source port Trunk Group 1 Port Membership Trunk1Ports Register Port trunking exampleTrunk Group 0 Port Membership Trunk0Ports Register Extended port awareness Flow control Multicast limit Other flow-control mechanismsHardware flow control System test capabilities Reading Rdram Internal wrap test Duplex wrap test PHY TNETX4090 Recommended operating conditions MIN NOM MAX Unit Timing requirements over recommended operating conditions Jtag interface Control signalsReset see Figure Physical medium attachment interface port Receive PMA receive see Figure Transmit PMA transmit see Figure Gmii transmit see Figure Gmii portGmii receive see Figure PMA and Gmii clock see Figure Gmii Clock MII ports 0±8 MII receive see Figure MII transmit see Figure MII clock see Figure Dtxclk Drxclk Rdram interfaceRdram see Figure Dbusctrl Dbusen SCS Srnw SAD1±SAD0 Sdma SDATA7± SDATA0 Srdy Sint DIO interfaceDIO and DMA writes see Figure DIO and DMA reads see Figure SCS Srnw SAD1±SAD0 Sdma SDATA7± SDATA0 Srdy Eeprom reads see Figure Eeprom interfaceEeprom writes see Figure Ledclk Leddata LED interfaceLED see Figure VOH VOL TTL Output Macro Propagation-Delay-Time Voltage Waveforms VOL VDD VDD VOH50% Lvcmos Mechanical Data TNETX4090GGP Obsolete BGA TBD Important Notice