EEPROM Interface

Table 5-1. Component Identification

 

 

 

 

 

 

 

 

 

Stepping

Vendor ID

Device ID

Description

 

 

 

 

 

 

 

 

82541GI-B1

8086h

1076h

Cooper

 

 

 

 

 

 

 

 

82541GI-B1

8086h

1077h

Mobile

 

 

 

 

 

 

 

 

82541PI-C0

8086h

1076h

Cooper

 

 

 

 

 

 

 

 

82541ER-C0

8086h

1078h

Cooper

 

 

 

 

 

 

 

 

82540EP-A

8086h

1017

Desktop

 

 

 

 

 

 

 

 

82540EP-A

8086h

1016

Mobile

 

 

 

 

 

 

 

 

82540EM-A

8086h

100E

Desktop

 

 

 

 

 

 

 

 

82540EM-A

8086h

1015

Mobile

 

 

 

 

 

 

 

Note: These Ethernet controllers also provide identification data through the Test Access Port (TAP).

5.3EEPROM Device and Interface

The EEPROM access algorithm, programmed into the Ethernet controller, is compatible with most, but not all, commerically available 3.3 V dc Microwire* interfaces and serial EEPROM devices with a 1 MHz speed rating. Ethernet controllers are compatible with two sizes of 4-wire serial EEPROM devices1. If ASF mode functionality is desired, a 4096-bit serial NM93C66 compatible EEPROM can be used. Otherwise, a 1024-bit serial NM93C46 compatible EEPROM can be used. Both EEPROMs are accessed in 16-bit words; the larger has 256 words while the smaller has 64 words. Refer to the appropriate Ethernet controller’s design guide for recommended EEPROM manufacturers.

An Ethernet controller automatically determines which EEPROM it is connected to and sets the EEPROM SIZE field of the EEPROM/FLASH Control and Data Register (EEC.EE_SIZE) field appropriately. Software can use this field to determine how to access the EEPROM using direct access. Note that different EEPROM sizes have different numbers of address bits and therefore must be accessed with a slightly different serial protocol. Software must be aware of this if it accesses the EEPROM using direct access.

1.The 82544GC/EI only supports one size of EEPROM. Refer to the 82544GC Gigabit Ethernet Controller Datasheet and Hardware Design Guide (AP-427) for more information.

Software Developer’s Manual

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Intel PCI-X, Intel Gigabit Ethernet Controllers manual Eeprom Device and Interface