lan9220 Standard Microsystems Corp., lan9220 Datasheet - Page 39

• Manufacturer Part Number: lan9220
• Description: 16-bit Non-pci Small Form Factor 10/100 Ethernet Controller With Variable Voltage I/o & Hp Auto-mdix Support
• Manufacturer: Standard Microsystems Corp.

16-bit Non-PCI Small Form Factor 10/100 Ethernet Controller with Variable Voltage I/O & HP Auto-MDIX Support
Datasheet
SMSC LAN9220
3.9.2.1
If an operation is attempted, and an EEPROM device does not respond within 30mS, the LAN9220
will timeout, and the EPC timeout bit (EPC_TO) in the E2P_CMD register will be set.
Figure 3.4, "EEPROM Access Flow Diagram"
EEPROM Read or Write operation.
The host can disable the EEPROM interface through the GPIO_CFG register. When the interface is
disabled, the EEDIO and ECLK signals can be used as general-purpose outputs, or they may be used
to monitor internal MII signals.
Supported EEPROM Operations
The EEPROM controller supports the following EEPROM operations under host control via the
E2P_CMD register. The operations are commonly supported by “93C46” EEPROM devices. A
description and functional timing diagram is provided below for each operation. Please refer to the
E2P_CMD register description in
page 102
Busy Bit = 0
for E2P_CMD field settings for each command.
EEPROM Write
Figure 3.4 EEPROM Access Flow Diagram
Write Data
Command
Command
Register
Register
Register
Write
Read
Idle
Section 5.3.23, "E2P_CMD – EEPROM Command Register," on
DATASHEET
39
illustrates the host accesses required to perform an
EEPROM Read
Read Data
Command
Command
Register
Register
Register
Write
Read
Idle
Busy Bit = 0
Revision 2.6 (12-04-08)