TDM (E1) transport over ATM AAL1

Robert Douglas rdouglas15 at
Wed Nov 6 04:55:34 EST 2002

I am using a MPC850DSL @ 50Mhz. The UTOPIA interface
runs at 25Mhz but the ATM PHY transmits at (2048 + ATM
OH)k bits/sec.
We intend to use the AAL0 mode available in this model
of PowerPC.
Regarding how many interrupts/sec we excpect, I think
one interrupt per ATM cell would consume too much CPU,
but the delay would be smaller. I guess we'll only
know the exact number of interrupts after doing some
prototype testing.

PS.: the Zarlink chips would fit very well in this
application....if they had a SINGLE-CHANNEL part.


----------  Forwarded Message  ----------

Subject: TDM (E1) transport over ATM AAL1
Date: Tue, 5 Nov 2002 15:10:05 +0000
From: Philip.Lougher at Zarlink.Com
To: linuxppc-embedded at

Um, it's rather difficult to say without knowing
*anything* about your
hardware.  Embedded PowerPC cores vary considerably in
performance between
models/make.  You also don't mention how many
interrupts you expect per
second - is there going to be an interrupt per ATM


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