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JTAG and processor ID

Started by Michael Rinder January 28, 2004
Hi,

We are designing a board with more than one Tigersharc connected.
The DSP's aren't goint to share memory i.e., they aren't connected in
multiprocessor mode.
They are on the other hand going to have separate SDRAM connected, which
implies that they all need to have processor id = 000 (only ID0
initializes SDRAM).

However, we would like to be able to access them via a single ICE-
emulator and the JTAG-ports.

Does the multiprocessor ID have anything to do with the use of the JTAG.
i.e., can we have more than one Processor ID000 connected to the same
JTAG chain?
-We think we can but we aren't 100% certain.

Thanx and regards

Michael



On Wed, 28 Jan 2004, Michael Rinder wrote:

> We are designing a board with more than one Tigersharc connected.
> The DSP's aren't goint to share memory i.e., they aren't connected in
> multiprocessor mode.
> They are on the other hand going to have separate SDRAM connected, which
> implies that they all need to have processor id = 000 (only ID0
> initializes SDRAM).
>
> However, we would like to be able to access them via a single ICE-
> emulator and the JTAG-ports.
>
> Does the multiprocessor ID have anything to do with the use of the JTAG.
> i.e., can we have more than one Processor ID000 connected to the same
> JTAG chain?
> -We think we can but we aren't 100% certain.

I've never had the opportunity to try it, but it should be fine. The JTAG
chain is totally independent of processor number, the position in the
chain determines which device you talk to. So it should work ok.

Patience, persistence, truth,
Dr. mike



Thank you for your quick responses Friedrich and Dr. Mike.

-In fact, I had my assumptions validated shortly after writing the mail
by searching in comp.dsp.

Thanx again
Michael, Denmark


--On Wednesday, January 28, 2004 9:10 AM -0800 Mike Rosing
<> wrote:

> I've never had the opportunity to try it, but it should be fine. The JTAG
> chain is totally independent of processor number, the position in the
> chain determines which device you talk to. So it should work ok.

My dual-21065L target actually had the processor ID's reversed from the JTAG
order. Works fine, but confused the guy bringing up the board for the first
time. ;)