Realtek 8019AS + PIC18 Problem

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We have interfaced a Realtek NE200 clone (RTL8019AS) with a microchip
Our hardware has been mostly copied from the Microchip
board, and we are using the Microchip stack.

However we are facing a strange problem. We are not able to
communicate with the NIC. If we request the MAC Address, for example,
we get 10:30:50:70:90:b0
instead of 12:34:56:78:9a:bc.. ie the second nibble of every byte is
always zero. We are using the NIC in 8-bit mode.

Could it be a problem of soldering? - we have two identical boards
showing this same problem... Or could it be due to the oscillator
being too close to the data lines? We are absolutely perplexed.. can
anybody suggest ways to debug such problems?

Our layouts can be accessed at

Any help will be highly appreciated!!
Nikhil Patil

Re: Realtek 8019AS + PIC18 Problem
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I have seen this problem before, and if I remember correctly, it is a known
problem in the NIC chip you are using. Try google for a work around.

Re: Realtek 8019AS + PIC18 Problem
On Sat, 4 Oct 2003 15:50:25 +1000, "The real Andy"

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I've done around 6 Realtek designs with various CPUs and MCUs, and
have never seen this problem. If you copy the properly,
it'll work fine.

Jeremy Bentham
Iosoft Ltd.

Re: Realtek 8019AS + PIC18 Problem
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Out of my (limitted) experience, such effects often point towards
timeing issues with waitstates etc. Are you sure you are within the
specs of the RealTek here?


Re: Realtek 8019AS + PIC18 Problem

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It was a few months ago, but I seem to remember this is the same problem I had
to some page 3 registers that don't exist on an original NE2000. Whether or not
the RTL8008 implements these or not, I don't know. I couldn't get a data sheet
out of Realtek. They said they couldn't find it on their FTP server! How about
getting of your arses, guys!!! Anyway, although the RTL8019AS implements these
registers, it might be a good idea to try and temporarily comment out any code
that accesses page 3 registers to see if that helps.

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