TNETX3270

ThunderSWITCH24/3 ETHERNETSWITCH

WITH 24 10-MBIT/S PORTS AND 3 10-/100-MBIT/S PORTS

SPWS043B ± NOVEMBER 1997 ± REVISED APRIL 1999

10-/100-Mbit/s MAC interfaces (ports 24±26)

Unlike the 10-Mbit/s ports, each 10-/100-Mbit/s port has a dedicated set of signals to interface to its PHY. Table 12 shows how a TNETE2101 10-/100-Mbit/s PHY would be connected to one of the 10-/100-Mbit/s ports of TNETX3270.

Table 12. 10-/100-Mbit/s Interface Connections

 

SWITCH

 

TNETE2101

TERMINAL

 

TERMINAL

 

 

 

 

 

 

 

MxxTCLK

MTCLK

 

 

 

 

 

 

 

MxxTXD3

MTXD3

 

 

 

 

 

 

 

MxxTXD2

MTXD2

 

 

 

 

 

 

 

MxxTXD1

MTXD1

 

 

 

 

 

 

 

MxxTXD0

MTXD0

 

 

 

 

 

 

 

MxxTXEN

MTXEN

 

 

 

 

 

 

 

MxxTXER

MTXER

 

 

 

 

 

 

 

 

MxxCOL

MCOL

 

 

 

 

 

 

 

 

MxxCRS

MCRS

 

 

 

 

 

 

 

MxxRCLK

MRCLK

 

 

 

 

 

 

 

MxxRXD3

MRXD3

 

 

 

 

 

 

 

MxxRXD2

MRXD2

 

 

 

 

 

 

 

MxxRXD1

MRXD1

 

 

 

 

 

 

 

MxxRXD0

MRXD0

 

 

 

 

 

 

 

MxxRXDV

MRXDV

 

 

 

 

 

 

 

MxxRXER

MRXER

 

 

 

 

 

 

 

 

MxxLINK

SLINK

 

 

 

 

 

 

 

 

MDCLK

MDCLK

 

 

 

 

 

 

 

 

MDIO

 

MDIO

 

 

 

 

 

 

 

 

 

 

 

 

MRESET

 

 

MRST

 

 

 

 

 

 

 

 

Where xx = 24, 25, or 26, y = 0±3

Other differences from the 10-Mbit/s ports are noted in following paragraphs.

10-/100-Mbit/s port configuration

The 100-Mbit/s ports (24±26) can negotiate with the PHY (speed and duplex) at power-up via the EEPROM contents using the MxxFORCE10 and MxxFORCEHD terminals, respectively.

Each of these terminals (per port):

DHas an integral 50-μA current-source pullup resistor. The system designer must decide if this is sufficient to achieve a logic-1 level in a timely manner or if an external supplementary resistor is required.

DHas a strong open-drain pulldown transistor, which is enabled by setting to 1 the appropriate bit in the Portxcontrol register.

DIs connected (via synchronization logic) to the appropriate bit in the Portxstatus register. These bits directly control the configuration of the ports.

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Texas Instruments TNETX3270 specifications 10-/100-Mbit/s MAC interfaces ports 24±26, Mbit/s Interface Connections