Re: multiple analog blocks in a module

Hi, Dave -
I have similar recollections as you, but the LRM doesn't spell it out.
The code you say is "equivalent" adds a begin/end wrapper around the
two original blocks. I don't recall if this ever matters.

-Geoffrey

Dave Miller wrote:
> If I remember correctly, the idea behind the "concatenated in the
> order they appear in the module" stmt was so we could define the order in which
> the blocks are evaluated, avoiding problems with OOMR etc.
>
> So in your example below I would interpret it to be equivalent to:
>
>
> analog begin
> begin : block1
> real x;
> x = V(a);
> I(a) <+ x * 1.0;
> end
> begin : block2
> x = V(a);
> I(a) <+ x * 2.0;
> end
> end
>
>
> As such, the reference to variable 'x' in block 2 is illegal as it is out of
> scope.
> So x = V(a) is illegal as we are assigning to a variable declared in another
> scope (5.3.2)
>
> Reference of x in the contribution should be using the hierarchical name:
> I(a) <+ block1.x * 2.0;
>
> If you wish to assign to 'x' in block2, you would need to declare 'x' in the
> module scope.
>
> > And, if x had been declared in block2, is the compiler required to keep
> block1.x distinct from block2.x ?
>
>
> Yes (5.3.2) variables declared in blocks are distinct/unique. So the compiler
> would keep them separate (same goes for parameters declared in named blocks.
>
> At least that is how I interpret the use of named blocks and variables etc.
>
> Cheers...
> Dave
>
> On 05/21/2012 11:26 AM, Geoffrey Coram wrote:
>> Hi -
>> I have some questions about multiple analog blocks, working from LRM 2.3.1.
>>
>> In section 5.2, it says
>> Multiple analog blocks can also be used within a module declaration.
>> Refer section 7.1 for more details on multiple analog blocks
>>
>> but 7.1 doesn't seem to be the right section. I found some more on
>> multiple analog blocks in 6.2, which says:
>>
>> A module definition may have multiple analog blocks. The behavior
>> of multiple analog blocks shall be defined by assuming that the
>> multiple analog blocks internally combine into a single analog block
>> in the order that the analog blocks appear in the module description.
>> In other words, they are concatenated in the order they appear in the
>> module. Concurrent evaluation of the multiple analog blocks is
>> implementation dependent as long as the behavior in that case is
>> similar to what would happen if they had been concatenated.
>>
>> What I don't see is any discussion of how one concatenates *named*
>> analog blocks -- and the scope of variables declared therein.
>>
>> analog begin : block1
>> real x;
>> x = V(a);
>> I(a) <+ x * 1.0;
>> end
>> analog begin : block2
>> x = V(a);
>> I(a) <+ x * 2.0;
>> end
>>
>>
>> I would expect this to be illegal, since x is not declared in block2,
>> but I don't know what the concatenation looks like. And, if x had
>> been declared in block2, is the compiler required to keep block1.x
>> distinct from block2.x ?
>>
>> -Geoffrey
>>
>>
>

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