Intel PCI User Manual

123

All Ethernet controllers except the 82540EP/EM provide an external parallel interface to an 

optional FLASH or boot EEPROM device. Accesses to the FLASH memory are controlled by the 
Ethernet controllers, but are accessible to host software as normal PCI reads or writes to the 

FLASH memory mapping range. Software developers can also map FLASH memory to I/O space. 

The Ethernet controllers support 8-bit wide parallel FLASH memory up to 4 Mb (512 KB); an 
appropriate size for typical applications would be 1 Mb (128 KB). The size of the FLASH 

implemented in the design can be encoded into bits in the EEPROM. FLASH and expansion ROM 

base address registers are reconfigured based on these EEPROM settings.

Representative FLASH memory devices that have been found to work satisfactorily with the 
Ethernet controllers are listed in 

The FLASH memory interface trace routing is not critical because the interface runs at a very slow 

speed. In a tightly space-constrained design, the FLASH memory device is a good choice for 
placement in relative isolation from the Ethernet controllers.

Note: The 82540EP/EM provides an external interface to a serial FLASH or Boot EEPROM device. See 

 for more information.

Atmel

AT49LV010
AT49BV002AN-70J1

Silicon Storage 
Technology

SST39V512
39VF020-90-4I-NH
39VF020-70-4C-NH