LAN9303 Datasheet, PDF (112/366 Pages) SMSC Corporation – Small Form Factor Three Port 10/100 Managed Ethernet Switch with Single MII/RMII/Turbo MII

Small Form Factor Three Port 10/100 Managed Ethernet Switch with Single MII/RMII/Turbo MII
Datasheet
(E2P_CMD) must be configured with the desired command value and the read address, respectively.
The READ command is executed by setting the EEPROM Controller Busy (EPC_BUSY) bit of the
EEPROM Command Register (E2P_CMD). The completion of the operation is indicated when the
EEPROM Controller Busy (EPC_BUSY) bit is cleared, at which time the data from the EEPROM may
be read from the EEPROM Data Register (E2P_DATA).
The RELOAD operation is performed by writing the RELOAD command into the EEPROM Controller
Command (EPC_COMMAND) field of the EEPROM Command Register (E2P_CMD). The command
is executed by setting the EEPROM Controller Busy (EPC_BUSY) bit of the EEPROM Command
Register (E2P_CMD). In all cases, the software must wait for the EEPROM Controller Busy
(EPC_BUSY) bit to clear before modifying the EEPROM Command Register (E2P_CMD).
If an operation is attempted and the EEPROM device does not respond within 30mS, the device will
time-out, and the EEPROM Controller Timeout (EPC_TIMEOUT) bit of the EEPROM Command
Register (E2P_CMD) will be set.
Figure 8.6 illustrates the process required to perform an EEPROM read or write operation.
EEPROM Write
EEPROM Read
Idle
Idle
Write
E2P_DATA
Register
Write
E2P_CMD
Register
Write
E2P_CMD
Register
EPC_BUSY = 0
Read
E2P_CMD
Register
Read
E2P_CMD
Register
EPC_BUSY = 0
Read
E2P_DATA
Register
Figure 8.6 EEPROM Access Flow Diagram
Revision 1.3 (08-27-09)
112
DATASHEET
SMSC LAN9303/LAN9303i