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Re: Embedded Ethernet

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at this stage I'd rather not switch cores simple because i don't have the
development tools to play with the 8051 you've sugested, although it does
look like a very attractive micro.

Do you have any idea who distributes the LAN91C111 in Australia?


Re: Embedded Ethernet

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You have to build a byte cross-over buffer between the 8051 and 91C111 to
bridge the bus-width gap. LAN91C111 does not support 8 bit bus.

Think twice if 100 Mbit/s is really needed - for a 8051 even 10 Mbit/s is an

Tauno Voipio
tauno voipio @ iki fi

Re: Embedded Ethernet
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I don't think that is true. We are using the 91c111 on an 8 bit bus
(the processor can do up to 32 but we need the other 24 pins ad I/O).
You can attach both halves of the 16 bit bus to the same 8 bit
processor bus (bit  0 = bit 8 etc.) and program the 91c111 to only
send/receive 8 bits at a time. This does not work if you want the
fastest DMA transfers since these are only possible on a 16 bit bus
but should work for normal processor I/O and 8 bit dual address DMA.

Phil Smith, sometimes G8JSL or M3JSL

Embedded software, Robotics, CAN and Consultancy.

Re: Embedded Ethernet

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Projec Systems ETHERNET Controlled Web Server at:
may be of interest.

Don McKenzie  E-mail:
              Home Page:

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Re: Embedded Ethernet
Atmel has a reference design kit.

They use Crystal CS8900 chip. (I am putting one in a new design too). The
only drawback -- it is 10BaseT only, but I do not think you will use
100BaseT on a little micro anyway.


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Re: Embedded Ethernet

This is the chip you want.  NE2000 like the RTL8019AS, but 10/100; 5v
tolerant, but runs on 3.3v; LQFP-128 instead of TQFP-100.  I've got one
wired to an Mega128 in 16-bit mode, due to a similar migration from the
RTL8019AS (for identical reasons).  Only very slight extensions from
your NE2000 driver to configure the 100Mb features.

For prototyping, this built board is actually cheaper than buying the
chips from Singapore (at least for the USA), and he'll sell you 1-off
chips too.  Even with your proximity, you may find he offers a better
deal.  (ASIX wanted $60USD for qty 1, plus s&h from Singapore.) /

The fellow who hosts this page also wrote an article in ~October 2002 in
CircuitCellar magazine discussing how to connect the Mega128 (in an
Atmel STK500 kit) with this proto board.

You are spot-on in your reasoning for switching controllers, although
technically the failing is in the RTL8019AS' ability to auto-negotiate.
It's just not part of the 10Mb spec.

While the 8019 can be forced into full-duplex mode to eliminate
collisions, detecting whether the switch is in FDX mode is a problem.
And this is also one of only two 8019 settings you can't elect through a
register - you have to install or emulate the EEPROM.


Re: Embedded Ethernet

See the following URL for details of a design using ASIX Ax88796.


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Re: Embedded Ethernet
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The best one i have seen latey is the lantronix part that has the whole lot
in one RJ-45 socket. Good if your only doing a few, probably not so good if
you are an OEM. Soanar (polykom) do these parts. Not sure of the cost, but
I'm guessing they are probably not to badly priced.

Other solution is to use a NE2000 NIC. Dead simple!

Re: Embedded Ethernet
On Thu, 26 Jun 2003 17:49:34 +1000, "Andy, The Real"

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The list price for the Lantronix Xport is $49 US.
Been thinking about dropping one of these into my 1xrtt RTU project.

Re: Embedded Ethernet
On Thu, 26 Jun 2003 00:19:59 +1000, "Craig Rodgers"

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If 4 or less comcurrent TCP/IP connections is good enough, then the
Wiznet W3100A is a nice device. It runs the TCP/IP stack in hardware,
hence the amount of code to write for a TCP/IP connection is quite
simple. Also because it handles the TCP/IP, the AVR is only bothered
when a packet destined for it's node has been received. They also have
a number of modules available that includes the W3100A IC, together
with the phy-chip and the magnetics + connector.

   Anton Erasmus

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