SMSC LAN9311 User Manual

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

Revision 1.4 (08-19-08)

152

SMSC LAN9311/LAN9311i

 

Following the release of nRST, POR, DIGITAL_RST, or a RELOAD command, the EEPROM Loader
starts by reading the first byte of data from the EEPROM. If the value of A5h is not read from the first
byte, the EEPROM Loader will load the current configuration strap values into the PHY registers (see

) and then terminate, clearing the EPC_BUSY bit in the 

. Otherwise, the EEPROM Loader will continue reading sequential bytes from the

EEPROM.

The next six bytes in the EEPROM, after the EEPROM Valid Flag, are written into the 

 and 

, and

the 

. The EEPROM bytes are written into the MAC

address registers in the order specified in 

. Refer to 

 for additional information on MAC address loading.

While the EEPROM Loader is in the wait state, if a Host MAC reset is detected (via the Soft Reset bit
in the 

), the EEPROM Loader will read byte 0. If the byte

0 value is A5h, the EEPROM Loader will read bytes 1 through 6 from the EEPROM and reload the

. During this time, the EPC_BUSY bit in the 

 is set. 

The switch MAC address registers are not reloaded due to this condition.

The 7

th

 byte of data to be read from the EEPROM is the Configuration Strap Values Valid Flag. If this

byte has a value of A5h, the next 4 bytes of data (8-11) are written into the configuration strap registers
per the assignments detailed in 

. If the flag byte is not A5h, these next 4 bytes are skipped

(they are still read to maintain the data burst, but are discarded). However, the current configuration
strap values are still loaded into the PHY registers (see 

 for more information on the LAN9311/LAN9311i configuration

straps.

Some PHY register defaults are based on configuration straps. In order to maintain consistency
between the updated configuration strap registers and the PHY registers, the 

, 

, and 

written when the EEPROM Loader is run.

Byte 8

BP_EN_ 

strap_1

FD_FC_ 

strap_1

manual_ 

FC_strap_1

manual_mdix

_strap_1

auto_mdix_

strap_1

speed_ 
strap_1

duplex_ 

strap_1

autoneg_ 

strap_1

Byte 9

BP_EN_ 

strap_2

FD_FC_ 

strap_2

manual_ 

FC_strap_2

manual_mdix

_strap_2

auto_mdix_

strap_2

speed_ 
strap_2

duplex_ 

strap_2

autoneg_ 

strap_2

Byte 10

LED_fun_strap[1:0]

BP_EN_ 

strap_mii

FD_FC_ 

strap_mii

manual_FC

_strap_mii

speed_ 

strap_mii

duplex_pol_ 

strap_mii

SQE_test_ 

disable_strap

_mii

Byte 11

LED_en_strap[7:0]