Re: [uClinux-dev] ARM7TDMI + RT8019AS

From: Willy Smith (numatico@racsa.co.cr)
Date: Wed Jan 17 2001 - 18:05:59 EST


John,

Are you sure it's a software problem? Is this a new board design that hasn't been (software) tested before? Is there a hardware handshake implemented between the 8019 and the 32C50100? This could be the problem.

In my experience, having a processor hang with just a store instruction is not a software problem. Or maybe I just am not understanding the exact sequence of events?

Regards,

Willy Smith
Costa Rica

At 01:59 PM 1/17/01 -0800, you wrote:
>I'm working on a board containing an ARM7TDMI based Samsung part (the
>KS32C50100-01).  Hooked to the nECS2 pin is an Realtek RT8019AS ethernet
>controller.
>
>I've been trying to get the processor to talk to the 8019, but so far all I
>get are hung systems.  This is the first external device I've played with --
>so I suspect I'm just doing something stoopid.
>
>Here's the math I've used:
>
>My REFEXTCON register's address is 0x3ff303c.
>   0x9c218360  REFEXTCON's contents
>&  0x000003ff  Need 10 bits for Ext IO Bnk0 base ptr
>=  0x00000360
><< 16          From page 4-41 of KS32C50100 manual
>=  0x03600000
>+  0x00008000  My 8019 is on nECS2, so 2*0x4000
>=  0x03608000
>|  0x04000000  Noncachable area
>=  0x07608000
>+  0x00000300  Base address of NIC
>=  0x07608300  This should be the cmd addr of the NIC
>
>I tried storing an 0x21 (E8019_NODMA+E8019_STOP) to 0x7608300.  As soon as I
>do the machine hangs.  For grins, I tried writing the same to 0x43608300,
>0x3608300 -- same results.
>
>I imagine I'm just blowing the math or am mis-understanding how this stuff
>works.  Can anyone set me straight (or point me to a document that will?)
>
>Thanks,
>John Lombardo
>
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