concatenation problem + difference between mod and rem

[Mohammed khader]

Hi all,

1) Why it is not possible to concatenate two bits to make a vector in
the following example.

signal s1,s2 :bit;

case (s1 & s2 ) is
WHEN "00" => ...


end case;

2) What is the advantage in having two operators(mod and rem ) which
seems almost similar.Is there any good reason(application) where they
have specific meaning.

Thanks in advance.

Regards,
Mohammed A.khader.

 

[Alan Fitch]

Hi all,

1) Why it is not possible to concatenate two bits to make a vector in
the following example.

signal s1,s2 :bit;

case (s1 & s2 ) is
WHEN "00" => ...


end case;

Because the data type is not determinable by the compiler.

2) What is the advantage in having two operators(mod and rem ) which
seems almost similar.Is there any good reason(application) where they
have specific meaning.

They differ in behaviour for signed values.

Alan


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Alan Fitch
Consultant

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