lan9312 Standard Microsystems Corp., lan9312 Datasheet - Page 138

• Manufacturer Part Number: lan9312
• Description: Lan9312 High Performance Two Port 10/100 Managed Ethernet Switch With 32-bit Non-pci Cpu Interface
• Manufacturer: Standard Microsystems Corp.

Revision 1.2 (04-08-08)
10.2.1
EEPROM Controller Operation
I
(E2P_CMD)
In Microwire EEPROM mode, the following operations are supported:
Note: In I
Note: The EEPROM Loader uses the READ command only.
The supported commands of each mode are detailed in
Register (E2P_CMD)," on page
Microwire) are explained in
respectively.
When issuing a WRITE, or WRAL command, the desired data must first be written into the
Data Register
EPC_COMMAND field of the
value. If the operation is a WRITE, the EPC_ADDRESS field in the
(E2P_CMD)
bit of the
when the EPC_BUSY bit is cleared.
When issuing a READ command, the EPC_COMMAND and EPC_ADDRESS fields of the
Command Register (E2P_CMD)
address, respectively. The READ command is executed by setting the EPC_BUSY bit of the
Command Register
bit is cleared, at which time the data from the EEPROM may be read from the
(E2P_DATA).
Other EEPROM operations (EWDS, EWEN, ERASE, ERAL, RELOAD) are performed by writing the
appropriate command into the EPC_COMMAND field of the
(E2P_CMD). The command is executed by setting the EPC_BUSY bit of the
Register
modifying the
Note: The EEPROM device powers-up in the erase/write disabled state. To modify the contents of
If an operation is attempted and the EEPROM device does not respond within 30mS, the LAN9312
will time-out, and the EPC_TIMEOUT bit of the
2
C and Microwire master EEPROM operations are performed using the
ERASE (Erase Location)
ERAL (Erase All)
EWDS (Erase/Write Disable)
EWEN (Erase/Write Enable)
READ (Read Location)
WRITE (Write Location)
WRAL (Write All)
RELOAD (EEPROM Loader Reload - See
are supported.
the EEPROM, the EWEN command must first be issued.
EEPROM Command Register (E2P_CMD)
(E2P_CMD). In all cases, the software must wait for the EPC_BUSY bit to clear before
2
C EEPROM mode, only a sub-set of the above commands (READ, WRITE, and RELOAD)
and
must also be set to the desired location. The command is executed when the EPC_BUSY
EEPROM Command Register
(E2P_DATA). The WRITE or WRAL command may then be issued by setting the
EEPROM Data Register
(E2P_CMD). The completion of the operation is indicated when the EPC_BUSY
Section 10.2.2, "I2C EEPROM"
High Performance Two Port 10/100 Managed Ethernet Switch with 32-Bit Non-PCI CPU Interface
EEPROM Command Register (E2P_CMD)
must be configured with the desired command value and the read
197. Details specific to each EEPROM controller mode (I
DATASHEET
138
(E2P_DATA).
(E2P_CMD).
Section 10.2.4, "EEPROM
EEPROM Command Register (E2P_CMD)
is set. The completion of the operation is indicated
and
Section 14.2.4.1, "EEPROM Command
Section 10.2.3, "Microwire EEPROM"
EEPROM Command Register
EEPROM Command Register
EEPROM Command Register
Loader")
to the desired command
EEPROM Data Register
EEPROM Command
SMSC LAN9312
will be set.
EEPROM
EEPROM
EEPROM
Datasheet
2
C and