Define Unsigned Type

[a_Conan]

Hi,
Can I define Unsigned Type in vhdl as:

package MyTypes is
Type UNS16 is array(15 downto 0) of unsigned;
end MyTypes;

Thanks

 

[Nicolas Matringe]

Can I define Unsigned Type in vhdl as:

package MyTypes is
Type UNS16 is array(15 downto 0) of unsigned;
end MyTypes;

No, you must use a fixed length unsigned.

Nicolas

 

[a_Conan]

Thank you Nicolas, but what do you meen by I must use a fixed length
unsigned?
Can you give example?

Thank you

 

[Nicolas Matringe]

You have to constrain your unsigned:
type uns16 is array(15 downto 0) of unsigned(7 downto 0);

Unless your unsigned type is not the one defined in numeric_std...

You can also define a 2D array of std_logic elements if you want your
type to be scalable but it has many drawbacks.

Nicolas

 

[a_Conan]

Thank You Nicolas...