Re: [lwip-users] Hardware Assisted Checksum

[Timmy Brolin]

I guess Ethernet MACs integrated into PC chipsets may have this feature, 
especially the gigabit interfaces.
But I have never seen this in a Ethernet MAC intended for embedded 
systems. Have you?
The only exception would be MACs implemented in FPGAs..

/Timmy Brolin

> It is common these days to have TCP/UDP/IP checksum assistance in 
> ethernet interface chips.  This is a very appropriate place for the 
> checksum, since everything is ready for checksumming by the time it 
> gets to the chip.
>
> The amount of preparation necessary in order to use this varies from 
> chip to chip.  For that reason, driver level work is required.  I 
> believe that FreeBSD and Linux driver interfaces have been modified to 
> accommodate the availability of checksumming services.  It may be an 
> appropriate future consideration for lwIP.
>
> If lwIP allowed checksumming services to be performed at the driver 
> level or beneath, then systems having special hardware - either in the 
> ethernet chip or some other FPGA - could be used.
>
> --
> Jim Gibbons
>         address@hidden
> Gibbons and Associates, Inc.
>         TEL: (408) 984-1441
> 900 Lafayette, Suite 704, Santa Clara, CA
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