configurations and generate

[Ralf Hildebrandt]

Hi all!

I have to write the configuration for a component, that contains some
subcomponents, that are instanced depending on generic parameters. Let
me give a theoretical example:


architecture behavior of top_component is

component subcomp
-- generic / port declaration
end component;


begin

gen_label_1 : if (gen_param=1) generate
instance_name_1 : subcomp
generic map(
... );
port map(
... );
end generate;

gen_label_2 : if (gen_param=2) generate
instance_name_2 : subcomp
generic map(
... );
port map(
... );
end generate;

-- and so on...

end behavior;


The configuration can be written as:

for behavior
for gen_label_1
for instance_name_1: subcomp use entity lib.subcomp(behavior);
end for; -- instance_name_1
end for; -- gen_label_1
for gen_label_2
for instance_name_2: subcomp use entity lib.subcomp(behavior);
end for; -- instance_name_2
end for; -- gen_label_2
-- and so on...
end for; -- behavior


If there are a lot of instances the configuration gets huge, too. In my
special case I want the same configuration for all instances of subcomp.
Additionally I have a second subcomponent (subcomp2), that is used quite
similar: many instances depending on generate statements. For subcomp2
everytime the same configuration is needed, too.
A for-generate is impossible, because of the unique port map of each
instance. So for simplifying the configuration I tried something like:

for behavior
for all
for all
subcomp use entity lib.subcomp(behavior);
subcomp2 use entity lib.subcomp2(behavior);
end for; -- all
end for; -- all
end for; -- behavior

But this is invalid. So my concluded question is:

Is there a way to say "take everytime this configuration for an instance
independet from logic depth of the block/generate labels"?


Ralf

 

[Mike Treseler]

But this is invalid. So my concluded question is:

Is there a way to say "take everytime this configuration for an instance
independet from logic depth of the block/generate labels"?

See pg 325 in Ashenden 2e,
about using a config declaration per entity.
See also:
http://groups.google.com/groups?q=v...hy+molenkamp+OR+fitch+OR+menchini+OR+ashenden

-- Mike Treseler

 

[Ralf Hildebrandt]

See pg 325 in Ashenden 2e,
about using a config declaration per entity.

As this book is not so easily available for me, I could only read your
recommended groups.google - links.

See also:
http://groups.google.com/groups?q=v...hy+molenkamp+OR+fitch+OR+menchini+OR+ashenden

One of these links is
http://groups.google.com/groups?q=v...F-8&[email protected]&rnum=2
It says (like I said, too) that a generate statement infers one level of
logical depth and therefore an component instance within a generate
statement is 2 levels deeper.
....
for gen_label_1
for instance_name_1: subcomp use entity lib.subcomp(behavior);
end for; -- instance_name_1
end for; -- gen_label_1
....
And if I read the related thread for this article, I only can find the
answer, that there is no way to specify the configuration for a block
deeper than one level away in general. Sorry, am I blind, or is this the
only answer?


Ralf

 

[Pieter Hulshoff]

Is there a way to say "take everytime this configuration for an instance
independet from logic depth of the block/generate labels"?

Not within a configuration I'm afraid. You'll either have to specify each
one individually, or not use a configuration file. Most simulators can work
without one, and synthesis often doesn't use configuration files anyway.

Regards,

Pieter Hulshoff

 

[Mike Treseler]

And if I read the related thread for this article, I only can find the
answer, that there is no way to specify the configuration for a block
deeper than one level away in general. Sorry, am I blind, or is this the
only answer?

Not the only answer.
When there is only one compiled module
per component and the names match,
you get a "default configuration"
without doing anything. Also the
last compiled architecture is the
default when there is more than one.

I prefer to use direct instances for
structure and generic constants for options.

-- Mike Treseler

 

[Ralf Hildebrandt]

I prefer to use direct instances for
structure and generic constants for options.

This is impossible, if one tries to insert a number of instances of a
subcomponent and this number depends on the generic parameter - but in
general: ACK.



O.k., many thanks to you and to Pieter for help!
Ralf