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Old 09-07-2006, 11:46 AM
KJ
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Default Re: alspin attribute


"alessandro basili" <[email protected]> wrote in message
news:[email protected]...
> Unfortunately I already tried it, but the problem is that
> "123,124,125,126" is a string, so Synplify does not complain anything, but
> to the alspin attribute this string does not make any sense (this is my
> understanding). This is very dependent on the synthesizer, because I've
> already done this for the Altera, using Quartus and the syntax was more or
> less this:
>
> attribute chip_pin : string;
> attribute chip_pin of address : signal is "@123,@124,@125,@126"
>
> In this case the string was interpreted as an "array of string", let's
> say, assigning the correct attribute to any bit of the bus.


Yes, but this interpretation as an 'array of strings' can only be done
within the context of the whole attribute setting first being a single VHDL
string. By that I mean that "@123,@124,@125,@126" is simply a VHDL string
whereas things like "123", "124".... are not which means that simply from a
VHDL language perspective it is not valid code.

Like I mentioned in the last post, what it sounds like you to do is check
the Actel documentation (or FAE or someone) for an example of how you can
assign attributes to a signal that is a vector. I don't think the issue is
with Synplify. Synplify has a method for assigning pins that you can't
follow because it puts this info in a separate constraint file instead of
the source and the single string method is the 'generic' way to pass any
attribute through but you basically don't know what format the Actel fitter
wants to see for that single string....so Actel would be the best source for
that info given that it doesn't appear that anyone on this newsgroup has
been able to chime in with what the correct syntax for that single string
should be.

KJ


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