Re: [avr-gcc-list] Another coding question

[Geoffrey Wossum]

On Thursday 05 August 2004 11:49 pm, Johan Nilsson wrote:

> Geoffrey Wossum is there any tcpip stack you recomend for Atmega 16 ? or
> should i go out and buy a Atmega 128 at once ? =)

If it was my project, I'd ask for a bigger part.  I'd take a look at Adam 
Dunkels' uIP (http://www.sics.se/~adam/uip/).  With everything configured on 
it, Adam says it consumes a little over 8 kB of code space on an AVR.  You 
can turn features off for a smaller foot print.  So the IP stack would fit on 
an ATmega16.  You'd probably be tight on RAM, though.  The MTU on Ethernet 
frames is 1500 bytes, so one Ethernet frame would eat most of your RAM.

You might also be low on I/O with such a small device.  My design used a 
CS8900 Ethernet chip.  We used the external memory bus on the ATmega128 to 
interface to the CS8900.  I have "AVR Embedded Web Server" board from ATmel 
that's also an ATmega128 + CS8900, interfaced the same way I think.  My 
design and ATmel's have 32kB of SRAM on them.  If you take a look at the 
Ethernut board, they use some RTL Ethernet chip, and also have additional 
SRAM.

Of course, I guess you could do SLIP to get to another device.  Not much I/O 
or additional RAM needed there...

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Geoffrey Wossum
Software Engineer
Long Range Systems - http://www.pager.net