SMSC LAN9311 User Manual

Two Port 10/100 Managed Ethernet Switch with 16-Bit Non-PCI CPU Interface

SMSC LAN9311/LAN9311i

139

Revision 1.4 (08-19-08)

 

I

2

C and Microwire master EEPROM operations are performed using the 

 and 

. 

In Microwire EEPROM mode, the following operations are supported:

„

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 

)

In I

2

C EEPROM mode, only a sub-set of the above commands (READ, WRITE, and RELOAD)

are supported.

The EEPROM Loader uses the READ command only.

The supported commands of each mode are detailed in 

. Details specific to each EEPROM controller mode (I

2

C and

Microwire) are explained in 

 and 

respectively.

When issuing a WRITE, or WRAL command, the desired data must first be written into the 

. The WRITE or WRAL command may then be issued by setting the

EPC_COMMAND field of the 

 to the desired command

value. If the operation is a WRITE, the EPC_ADDRESS field in the 

 must also be set to the desired location. The command is executed when the EPC_BUSY

bit of the 

 is set. The completion of the operation is indicated

when the EPC_BUSY bit is cleared.

When issuing a READ command, the EPC_COMMAND and EPC_ADDRESS fields of the 

 must be configured with the desired command value and the read

address, respectively. The READ command is executed by setting the EPC_BUSY bit of the 

. The completion of the operation is indicated when the EPC_BUSY

bit is cleared, at which time the data from the EEPROM may be read from the 

Other EEPROM operations (EWDS, EWEN, ERASE, ERAL, RELOAD) are performed by writing the
appropriate command into the EPC_COMMAND field of the 

. The command is executed by setting the EPC_BUSY bit of the 

. In all cases, the software must wait for the EPC_BUSY bit to clear before

modifying the 

The EEPROM device powers-up in the erase/write disabled state. To modify the contents of
the EEPROM, the EWEN command must first be issued.

If an operation is attempted and the EEPROM device does not respond within 30mS, the
LAN9311/LAN9311i will time-out, and the EPC_TIMEOUT bit of the 

 will be set.