SMSC LAN9420 - Manual (Page 36)

Single-Chip Ethernet Controller with HP Auto-MDIX Support and PCI Interface
Datasheet
Revision 1.22 (09-25-08) 36 SMSC LAN9420/LAN9420i
DATASHEET
READ (Read Location): This command will cause a read of the EEPROM location pointed to by EPC
Address (EPC_ADDR). The result of the read is available in the E2P_DATA register.
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 (EPC_ADDR). The EPC_TO bit is set if the EEPROM does not respond within
30ms.
Figure 3.12 EEPROM READ Cycle
Figure 3.13 EEPROM WRITE Cycle
1 1 0 A6
EECS
EECLK
EEDIO (OUTPUT) A0
D7 D0 EEDIO (INPUT)
t
CSL
0
EECLK
EEDIO (INPUT)
EEDIO (OUTPUT)
EECS
1 1 A6 A0 D7 D0
t CSL