LAN9303 Datasheet, PDF (127/366 Pages) SMSC Corporation – Small Form Factor Three Port 10/100 Managed Ethernet Switch with Single MII/RMII/Turbo MII

Small Form Factor Three Port 10/100 Managed Ethernet Switch with Single MII/RMII/Turbo MII
Datasheet
10.4 MII Mode Multiplexer
The MII mode multiplexer is used to direct the MII data/management path connections. One master
(MAC via the MII pins, or PMI) is connected to the slaves (PHY via MII pins, Port 1/2 PHYs, Virtual
PHY, and SMI slave) dependant on the selected management mode of the device. The MII mode
multiplexer also performs the multiplexing of the read data signals from the slaves and controls the
output enable of the MII pins.
The following sections detail the operation of the MII mode multiplexer in each management mode. A
list of management modes and their configuration settings are discussed in Section 2.3, "Modes of
Operation," on page 19.
10.4.1 Port 0 MAC Mode SMI Managed
In Port 0 MAC mode SMI managed, the internal PHYs and SMI slave block are accessed via the MII
management pins. The Virtual PHY and PMI are not used in this mode.
The Virtual PHY interface is accessible via the SMI slave or the EEPROM Loader. Refer to Section
10.2, "SMI Slave Controller," on page 124 and Section 8.4, "EEPROM Loader," on page 113 for
additional information.
Figure 10.1 details the MII multiplexer management path connections for this mode.
MDI SMI Slave
MDO
MDCLK
MDIO_ DIR
Parallel
Master
MDI Virtual PHY
MDO
MDCLK
MDIO_ DIR
Parallel
Slave
MDI PHY2
MDO
MDIO_ DIR
MDCLK
MDI PHY1
MDO
MDIO_ DIR
MDCLK
Management
Mode Selection
MII Pins
MDIO_ DIR
MDO
MDI
MDC_ DIR
MDC_ OUT
MDC_IN
MDIO
MDC
Management
Mode Selection
MDO MDCLK MDI MDO_EnN
PMI
Parallel Slave
Figure 10.1 MII Mux Management Path Connections - MAC Mode SMI Managed
SMSC LAN9303/LAN9303i
127
DATASHEET
Revision 1.3 (08-27-09)