Reading RTL8019AS registers

Hello group,

Need some support from u people .....

We are trying to connect 89c51 8-bit controller to Realtek Ethernet controller RTL8019AS. No external RAM is been used. We have used Packet Wacker (Ethernet board) available from

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I would like to know the least and the necessary connections required to kickstart the data transmission.

This is how we have connected....

1). SA0-SA4 connected to PORT2 - P2.0-P2.4 2). SD0-SD7 connected to PORT0 - P0.0-P0.7 3). INT0 connected to INT0 - P3.2 4). IOWB connected to WR - P3.6 5). IOWR connected to RD - P3.7 6). AEN tied to VCC 7). JP tied to VCC

To start with we tried to read the register 0x0A which contains the Chip ID...but in vain. All we could read was 0xFF.

Also tried to write to the CR register with 0x21...and read from it. Again wasn't able to read the correct value. what we read was 0xFF.

- How could we check our Realtek chip...?

- Is it proper to read the NIC's register without initialising it?

- Or do we require to recheck our connection....as the board (Packet Wacker) comes with only few pins "out" for connection.

Thx in advance...

Lawrie Kurian

Reply to
Lawrie Kurian
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IIRC, AEN is low active. If there is nothing else on the external bus, try tying it low.

HTH

Tauno Voipio tauno voipio @ iki fi

Reply to
Tauno Voipio

On 30 Sep 2003 06:13:58 -0700, snipped-for-privacy@greymatterindia.com (Lawrie Kurian) wrote: [.....]

Quote from the datasheet (page 6, at the top): "Address Enable. This ISA signal must be low for a valid I/O command."

Probably this is your problem.

Regards, /J.D.

--
Jan Dubiec, jdx@slackware.pl, mobile: +48 602 101787

G³êboka wiara wymaga p³ytkiego rozumu i nik³ej wiedzy.
Reply to
Jan Dubiec

In addition to previous posts :

I seem to recall that interrupt signals are active low on the 8051, so you need an inverter between the RTL and the 8051.

romuald

Lawrie Kurian wrote:

Reply to
romu

Thx for the reply... AEN is actually connected to low.... i mis-wrote it on the post.... anyways..was able to solve the problem.... We weren't giving a 2ms pulse on thr RSTDRV pin of RTL8019AS. After doing so... we were able to read the registers.

Lawrie Kurian.

Reply to
Lawrie Kurian

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