LAN9313 Datasheet, PDF (101/398 Pages) SMSC Corporation – Three Port 10/100 Managed Ethernet Switch with MII

Three Port 10/100 Managed Ethernet Switch with MII
Datasheet
Chapter 8 Serial Management
8.1
Functional Overview
This chapter details the serial management functionality provided by the LAN9313/LAN9313i, which
includes the EEPROM I²C/Microwire master, EEPROM Loader, SPI slave, and I²C slave controllers.
The I²C/Microwire EEPROM controller is an I²C/Microwire master module which interfaces an optional
external EEPROM with the system register bus and the EEPROM Loader. Multiple types
(I²C/Microwire) and sizes of external EEPROMs are supported. Configuration of the EEPROM type
and size are accomplished via the eeprom_type_strap and eeprom_size_strap[1:0] configuration straps
respectively. Various commands are supported for each EEPROM type, allowing for the storage and
retrieval of static data. The I²C interface conforms to the Philips I²C-Bus Specification.
The EEPROM Loader provides the automatic loading of configuration settings from the EEPROM into
the LAN9313/LAN9313i at reset, allowing the LAN9313/LAN9313i to operate unmanaged. The
EEPROM Loader module interfaces to the EEPROM Controller, Ethernet PHYs, and the system CSRs.
The SPI/I²C slave controller can be used for CPU serial management and allows CPU access to all
system CSRs. The SPI slave controller supports single register and multiple register read and write
commands. The I²C slave controller implements the low level I²C slave serial interface (start and stop
condition detection, data bit transmission/reception, and acknowledge generation/reception), handles
the slave command protocol, and performs system register reads and writes. The I²C slave controller
conforms to the Philips I²C-Bus Specification.
8.2
I²C/Microwire Master EEPROM Controller
Based on the configuration strap eeprom_type_strap, the I²C/Microwire EEPROM controller supports
either Microwire or I²C compatible EEPROMs. The I²C/Microwire serial management pins functionality
and characteristics differ dependant on the selected EEPROM type as summarized in Table 8.1.
Table 8.1 I²C/Microwire Master Serial Management Pins Characteristics
EEPROM
TYPE/MODE
I²C Master
EEPROM
Mode
eeprom_type_strap
=1
Microwire
Master
EEPROM
Mode
eeprom_type_strap
=0
EE_SDA/EEDI PIN
EE_SDA
Input enabled
(to I²C master)
Open-drain output
(from I²C master)
Pull-down disabled
EEDI
Input enabled
(to Microwire master)
Output disabled
Pull-down enabled
EEDO PIN
NOT USED
Input enabled
(used for straps)
Output enabled
(driven low)
EEDO
Input enabled
(used for straps)
Output enabled (from
Microwire master)
EECS PIN
NOT USED
Input enabled
(used for straps)
Output enabled
(driven low)
EECS
Input enabled
(used for straps)
Output enabled (from
Microwire master)
EE_SCL/EECLK PIN
EE_SCL
Input enabled
(to I²C master and
used for straps)
Open-drain output
(from I²C master)
EECLK
Input enabled
(used for straps)
Output enabled (from
Microwire master)
Note: When the EEPROM Loader is running, it has exclusive use of the I²C/Microwire EEPROM
controller. Refer to Section 8.2.4, "EEPROM Loader" for more information.
SMSC LAN9313/LAN9313i
101
DATASHEET
Revision 1.2 (04-08-08)