LAN9500 Datasheet, PDF (137/213 Pages) SMSC Corporation – USB 2.0 to 10/100 Ethernet Controller Promiscuous mode

LAN950x
Bits
30:28
27:11
Description
EPC Command
This field is used to issue commands to the EEPROM controller. The EPC
will execute commands when the EPC Busy bit is set. A new command must
not be issued until the previous command completes. This field is encoded
as follows:
000 = READ
001 = EWDS
010 = EWEN
011 = WRITE
100 = WRAL
101 = ERASE
110 = ERAL
111 = RELOAD
READ (Read Location): This command will cause a read of the EEPROM
location pointed to by EPC Address. The result of the read is available in the
E2P_DATA register.
EWDS (Erase/Write Disable): After issued, the EEPROM will ignore erase
and write commands. To re-enable erase/write operations, issue the EWEN
command.
EWEN (Erase/Write Enable): Enables the EEPROM for erase and write
operations. The EEPROM will allow erase and write operations until the
Erase/Write Disable command is sent, or until power is cycled.
Note:
The EEPROM device will power-up in the erase/write-disabled
state. Any erase or write operations will fail until an Erase/Write
Enable command is issued.
WRITE (Write Location): If erase/write operations are enabled in the
EEPROM, this command will cause the contents of the E2P_DATA register
to be written to the EEPROM location selected by the EPC Address field.
WRAL (Write All): If erase/write operations are enabled in the EEPROM, this
command will cause the contents of the E2P_DATA register to be written to
every EEPROM memory location.
ERASE (Erase Location): If erase/write operations are enabled in the
EEPROM, this command will erase the location selected by the EPC Address
field.
ERAL (Erase All): If erase/write operations are enabled in the EEPROM, this
command will initiate a bulk erase of the entire EEPROM.
RELOAD (Data Reload): Instructs the EEPROM controller to reload the data
from the EEPROM. If a value of A5h is not found in the first address of the
EEPROM, the EEPROM is assumed to be un-programmed and the Reload
operation will fail. The “Data Loaded” bit indicates a successful load of the
data.
Note:
A failed reload operation will result in no change to descriptor
information or register contents. These items will not be set to
default values as a result of the reload failure.
RESERVED
Type
R/W
RO
Default
000b
-
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DS00001875A-page 137