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type conversion of a custom enumeration type
von M. R. (rojo)

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Hi,

I defined an enumeration type ("reg") in a package header:
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LIBRARY ieee;

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USE ieee.std_logic_1164.all;

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USE ieee.std_logic_arith.all;

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...

...

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type reg is (R0, R1, R2, R3);

...and a conversion function which converts type "std_logic_vector" to 
my type "reg":

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function CONVTOREG (DATA :std_logic_vector) return reg;


In the body of the package I have the corresponding implementation of 
this conversion function:
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  function CONVTOREG (DATA :std_logic_vector) return reg IS

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    variable result :integer; 

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      begin 

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       result := CONV_INTEGER(unsigned(DATA));

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      return reg'VAL(result);

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  end function;


This works fine. Now I need another conversion function which converts 
the type "reg" back to std_logic_vector" which is declared like this:

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function CONV_REG_TO_STDLV (DATA :reg) return std_logic_vector;


But I don't know how to implement that since there is no type conversion 
which accepts my enumeration type. Has anybody an idea how to do that?

Thanks a lot!

Best regards.

M.R.

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Re: type conversion of a custom enumeration type
von user (Guest)

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this will do it:

function CONV_REG_TO_STDLV (DATA :reg) return std_logic_vector;
  return std_logic_vector(to_unsigned(reg'pos(DATA),2));

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Re: type conversion of a custom enumeration type
von M. R. (rojo)

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The 'pos attribute helped me.

Thanks a lot!

Best regards.

M.R.

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