LAN9312-NZW Standard Microsystems (SMSC), LAN9312-NZW Datasheet - Page 25

• Manufacturer Part Number: LAN9312-NZW
• Manufacturer: Standard Microsystems (SMSC)

Specifications of LAN9312-NZW

• Lead Free Status / RoHS Status: Supplier Unconfirmed

High Performance Two Port 10/100 Managed Ethernet Switch with 32-Bit Non-PCI CPU Interface
Datasheet
SMSC LAN9312
2.2.9
2.3
To Ethernet
To Ethernet
GPIO/LED Controller
The LAN9312 provides 12 configurable general-purpose input/output pins which are controlled via this
module. These pins can be individually configured via the GPIO/LED CSRs to function as inputs, push-
pull outputs, or open drain outputs and each is capable of interrupt generation with configurable
polarity. Two of the GPIO pins (GPIO[9:8]) can be used for IEEE 1588 timestamp functions, allowing
GPIO driven 1588 time clock capture when configured as an input, or GPIO output generation based
on an IEEE 1588 clock target compare event.
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.
In a typical application, the LAN9312 Host Bus Interface (HBI) is connected to the host
microprocessor/microcontroller via the asynchronous 32-bit interface, allowing access to the LAN9312
system configuration and status registers. The LAN9312 utilizes the internal Host MAC to provide a
network path for the host CPU. The LAN9312 may share the host bus with additional system memory
and/or peripherals. For more information on the HBI, refer to
page
The 2 Ethernet ports of the LAN9312 must be connected to Auto-MDIX style magnetics for proper
operation on the Ethernet network. Refer to the SMSC Application Note 8.13 “Suggested Magnetics”
for further details.
The LAN9312 also supports optional EEPROM and GPIOs/LEDs. When an EEPROM is connected,
the EEPROM loader can be used to load the initial device configuration from the external EEPROM
via the I
A system configuration diagram of the LAN9312 in a typical embedded environment can be seen in
Figure
System Configuration
Magnetics
Magnetics
99.
2.2.
2
C/Microwire interface.
GPIOs/LEDs
(optional)
Figure 2.2 System Block Diagram
LAN9312
DATASHEET
25MHz Crystal
External
25
I
2
C/Microwire
Chapter 8, "Host Bus Interface (HBI)," on
EEPROM
(optional)
Revision 1.7 (06-29-10)
Microprocessor/
Microcontroller
Peripherals
Memory
System
System