Altera free web FPGA software license question

Sander Vesik wrote:
> Nial Stewart <nial@nialstewartdevelopments.co.uk> wrote:

>>The MAC address should be unique for every piece of ehternet connectable
>>kit.

> at least in theory. most cards support changing it because well... 
> its just in a serial eeprom that can be read/written from the host.
> which is so because nobody wants to have two serial eeproms per card.

Traditionally it was stored in ROM, and at initialization the 
software driver would read the ROM and write into the 
appropriate register on the ethernet controller.

It might be that they are now in EEPROM, but I believe they are 
still read/written by software, in part to support systems that 
require special MAC addresses (DECNet, for one).

I don't know if license software uses the ROM/EEPROM address, or 
the one assigned to the ethernet hardware.

-- glen

On Mon, 21 Mar 2005 13:01:15 -0800, glen herrmannsfeldt <gah@ugcs.caltech.edu> wrote:

>Sander Vesik wrote:
>> Nial Stewart <nial@nialstewartdevelopments.co.uk> wrote:
>
>>>The MAC address should be unique for every piece of ehternet connectable
>>>kit.
>
>> at least in theory. most cards support changing it because well... 
>> its just in a serial eeprom that can be read/written from the host.
>> which is so because nobody wants to have two serial eeproms per card.
>
>Traditionally it was stored in ROM, and at initialization the 
>software driver would read the ROM and write into the 
>appropriate register on the ethernet controller.
>
>It might be that they are now in EEPROM, but I believe they are 
>still read/written by software, in part to support systems that 
>require special MAC addresses (DECNet, for one).
>
>I don't know if license software uses the ROM/EEPROM address, or 
>the one assigned to the ethernet hardware.
>
>-- glen

Many drivers allow a user-specified address to override the programmed in one. I would imagine any
licensing software uses the adddress that the driver gives (i.e. possibly modified), as otherwise it
would need to know about all the different types of card hardware.