LAN9313 Datasheet, PDF (23/398 Pages) SMSC Corporation – Three Port 10/100 Managed Ethernet Switch with MII

Three Port 10/100 Managed Ethernet Switch with MII
Datasheet
In addition, 8 of the GPIO pins can be alternatively configured as LED outputs. These pins, GPIO[7:0]
(nP1LED[3:0] and nP2LED[3:0]), may be enabled to drive Ethernet status LEDs for external indication
of various attributes of the switch ports.
2.3
Modes of Operation
The LAN9313/LAN9313i is designed to integrate into various embedded environments. To accomplish
compatibility with a wide range of applications, the LAN9313/LAN9313i can operate in 2 different
modes (MAC mode and PHY mode) and under various management conditions (unmanaged, SMI
managed, I²C managed, or SPI managed). The mode and management type of the
LAN9313/LAN9313i is determined by the MII_mode_strap and mngt_mode_strap[1:0] configuration
straps respectively. These modes and management types are detailed in the following sections.
Figure 2.2 displays a typical system configuration for each mode and management type supported by
the LAN9313/LAN9313i.
2.3.1 MAC Mode
The LAN9313/LAN9313i MAC mode utilizes an external PHY, which is connected to the MII pins, to
provide a third Ethernet network connection. In this mode, the LAN9313/LAN9313i acts as a MAC,
providing a communication path between the switch fabric and the external PHY. In MAC mode, the
LAN9313/LAN9313i may be unmanaged, SMI managed, I²C managed, or SPI managed as detailed in
Section 2.3.3, "Management Modes".
When an EEPROM is connected, the EEPROM loader can be used to load the initial device
configuration from the external EEPROM via the I²C/Microwire interface. Once operational, if
managed, the CPU can use the I²C/Microwire interface to read or write the EEPROM.
2.3.2 PHY Mode
The LAN9313/LAN9313i PHY mode utilizes an external MAC to provide a network path for the host
CPU. The external MII pins of the LAN9313/LAN9313i must be connected to an external MAC,
providing a communication path to the switch fabric. In PHY mode, the LAN9313/LAN9313i may be
unmanaged, SMI managed, I²C managed, or SPI managed as detailed in Section 2.3.3, "Management
Modes".
When an EEPROM is connected, the EEPROM loader can be used to load the initial device
configuration from the external EEPROM via the I²C/Microwire interface. Once operational, if
managed, the CPU can use the I²C/Microwire interface to read or write the EEPROM.
2.3.3 Management Modes
The LAN9313/LAN9313i provides various modes of management in both MAC and PHY modes of
operation. Two separate interfaces may be used to manage the LAN9313/LAN9313i: the I²C/SPI slave
interface or the SMI/MIIM(Media Independent Interface Management) slave interface.
The I²C/SPI interface runs as either an I²C slave or SPI slave and is used as a register access path
for an external CPU.
The SMI/MIIM interface runs as either an SMI/MIIM slave or MIIM master. The master mode is used
to access an external PHYs registers under CPU control (assuming the CPU is using I²C or SPI). The
slave mode is used for register access by the CPU or external MAC and provides access to either the
internal Port 1&2 PHY registers or to all non-PHY registers (using addresses 16-31 and a non-standard
extended address map). MIIM and SMI use the same pins and protocol and differ only in that SMI
provides access to all internal registers while MIIM provides access to only the Port 1&2 PHY registers.
A special mode provides access to the Virtual PHY, which mimics the register operation of a single
port standalone PHY. This is used for software compatibility during unmanaged operation.
The selection of LAN9313/LAN9313i modes is determined at startup via the MII_mode_strap and
mngt_mode_strap[1:0] configuration straps as detailed in Table 2.1. System configuration diagrams for
each mode of the LAN9313/LAN9313i are provided in Figure 2.2.
SMSC LAN9313/LAN9313i
23
DATASHEET
Revision 1.2 (04-08-08)