Be careful with CPUID...

Just a note to let people know that I just ran into an issue because I was relying on NIOSII_READ_CPUID to return the value of the CPU that is reflected in SOPC Builder.

It appears that with previous versions of SOPC Builder the CPUID started with zero at the top CPU in SOPC builder and incremented as it went down.

Altera never promised to keep this order, it was a sort of happy coincidence I guess.

From the Nios II Core Implementation Details:

<div class='quotetop'>QUOTE </div>

--- Quote Start ---

At system generation time, the cpuid control register (clt5) is assigned

a value that is guaranteed to be unique for each processor in the system.[/b]

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Now, with my four processor system, the .ptf file reports the CPU&#39;s are numbered:

1,2,0,3 in that order.

A lot of people are already aware of this, and there have been some threads in this forum, but I thought it might save someone some debug time to bring it up again.

Cheers,

Brian