Embedded ethernet

Just to make sure I understand what you are asking, you dont want to use ANY off the shelf ethernet chipset ?? you want to basically hook up an AVR/PIC to a 802.3 PHY layer and do all the link layer in code ?? Or are you talking about implemeting the PHY yourself ??

here is an example of a PHY for 802.3

Is that what you want to build, or does that get you what you need to work the higher layers in the microcontroller ??

I just did a little research -- if you are trying to implement a PHY, you need to go talk to the DSP people.. There isnt a microcontroller anywhere near fast enough to handle what a PHY does by any stretch of the imagination

If you are looking to implement the 802.3 MAC, there is an example at

for CPLD devices which might give you enough info to write a MAC for a microcontroller. However, I dont think any of the 8 bit controllers (AVR or PIC) could handle the job.. you'll need something with a much higher clock speed and better synchronous serial I/O capability than you can get in any 8 bit chip, and even then, dont bet on being able to handle anything more than 10 megabit... you need to implement the guts in hardware if you want to go faster than that.

On a sunny day (21 Feb 2007 00:48:15 -0800) it happened "devang" wrote in :

You can make life a bit easier for yourself with the W3100A:

Or buy a complete module iiM7000 (came with a RJ45 connector and magnetics in my case):

Also the C sources for TCP server etc. for this module are freely available on the net. Watch out, there is a (later) I2C, and a non-i2c version of the IIM7000 IIRC.

my case):

Dear All,

thank you very much for your replies.

I want to basically connect my project to TCP / IP or UDP network. I dont have much idea of doing it how to do it.

The only thing I know is i cant use any ready made ethernet to ttl converter. so yes I want to implement ethernet circuit and code on my own. I do have some basic knowledge of tcp/ip protocols with code.,(I have a reference book for that). but i dont know exactly where to start.

I think I will try to research more on the links you all have provided and will let you know about exact requirement.

Thanks & Regards, Devang Tanna

Oy is that all. Try this:

Paul Burke

Isnt that a "ready made ethernet to ttl converter" ??

In my opinion no, it requires mounting on a circuit board with a seperatly purchased transformer

Bob

ISTR there is already a project out there - tiny Ethernet or something like that?

--
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Well, it's CMOS for a start, and it requires transformers on the net side... but I suppose "TTL" (*) means "logic of any sort" in these dumbed down latter days. OK, if you have to make trouble, get hold of an eZ80F91 devkit and a KS8721 or something, and implement one of the examples that come with the network stack. For what you'll learn (if it is a college exercise) I can't see the difference really.

Paul Burke

(*) Grumble grumble... all that time spent learning why TTL was faster but had worse noise margin, if you want an industrial system use 15V

4000 series or better still those Norbrick chunks.

PIC18F**** and ENC28J60

Dear friends,

Thank you very much for all the responses.

I have also been watching enc28j60. that is the best ethernet controller available which is spi enabled and have builtin phy and mac within it. I referred it datasheet for my application.

I think it will suit my requirements.

Now , i came to know that it does ethernet framing on its own, which is again an advantage.

But how can I communicate with PC? using ENC28j60? I mean do i need to implement TCP/IP Stack with that????? I need tcp/ip and udp protocols for that. is source code available with microchip website?

I downloaded tcp/ip stack 4 but I dont understand exactly how to use it.

can anyone help me, please..........

Best Regards, Devang Tanna