ethernet with mega128

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Hello all.

I have to design an small low power ethernet interface with mega128.
There are several ethernet chip that will work. Like CS8900A, RTL8019AS and others.
Maybe there is somebody who has experience with several ethernet chips and can help me to choose the right chip.

I need to compare:
1) power consumption
2) software development
3) CPU time
4) Hardware expense
5) anything else important?

Thanks for your help.

Klaus
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Look at: www.megausb.de (German)
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uIP, is a C written package for ethernet tcp/ip

its almost ready to use. there are AVR versions availible for it if im correct.

Realtek has a 8/16 bit isa ethernet chip which requires only very few external parts such as a 100 ohm transformer. Ethernut is a ready to use avr solution which might solve you development / layout time .

if you want to design a full speed ethernet device you'd need something other then an AVR, or you'd have to come up with a DMA (direct mem access) scheme.

MY MICROCONTROLLER CAN BEAT THE HELL OUT OF YOUR MICROCONTROLLER /ATMEL

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Thanks MaxK,

DMA, controlled via PLD is a good idea to relax cpu time.

I have the datasheets of both the CS8900A and RTL8019AS. I am not familiar with TCP/IP yet. Are they about the same "intelligent" or does one need more intelligence in the ucontroller?

Thanks for your help

Klaus
********************************
Look at: www.megausb.de (German)
********************************

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RTL8019AS has a much lower power consumption than the CS8900A. As far as I remember, it is about 20-25mA compared to ~80mA. External part count is minimal. You may use an LF1S022 Ethernet jack with integrated transformer. This is without any signalling LEDs, but there are other manufacturers and types with integrated LEDs too.
The 'intelligence' of both controllers is comparable, the CS8900A does not produce reliable interrupts when in 8 bit mode. This does not matter to much though, as interrupts are not really necessary.
AS MaxK said, the uIP package is a very nice 'out of the box' solution, readily available under http://www.laskater.com/projects... as a port for AVR+RTL8019AS. There is also a port for the ASIX 10/100MBit Ethernet chip. I have ported the package to Fujitsu LX16 controllers, this was very easy and it works very reliably.
CPU load is not so critical (from my experience) as the data rate is mostly limited by other constraints (as for example the delayed acknowledge by most Windows systems).

Just some hints,
Jörg.

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Thera are also WizNet chip with TCP/IP stack,
but i use Xport/
Alexander

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Olimex has a cs8900a on a header board with transformer

Imagecraft compiler user

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As MaxK said

http://www.ethernut.de/

http://www.ethernut.de/en/hardwa...

They have public schematics , boardlayout , NutO/S and .. well the lots
You can even byt one to try out http://www.egnite.de/en/store.php

I'd use the Realtek
http://www.cornelius-consult.de/...

/Bingo

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Hello,

thanks a lot to you all.
This was great help.

I think i try the Realtek chip.

What i want to do:
Small stand alone Ethernet board. 2 user connections:
1) Ethernet
2) 8 bit parallel IO with bidirectional FIFO
Writing to FIFO will send data via Ethernet to a PC
Sending data from PC via ethernet will be sent to the FIFO.
--> easy to use datatransfer via ethernet.
(similar to the USB to parallel chip FT245BM from FTDI)
maybe with the ability of power over ethernet lines

Thanks again

Klaus
********************************
Look at: www.megausb.de (German)
********************************