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User defined types (Enum, Array, Record)

Enum​

Has different states with a custom name.

Example​

TYPE EnumType IS (start, running, end); 
SIGNAL EnumSig : EnumType := start; 

EnumSig <= running;

Array​

Allows to have a group of elements in one variable.

Example​

TYPE PixelType IS ARRAY (0 to 2) OF NATURAL range 0 to 255; 
TYPE RowType IS ARRAY (0 to 639) OF PixelType; 
(TYPE RowType IS ARRAY (0 to 639, 0 to 2) OF NATURAL range 0 to 255;) 
SIGNAL Row : RowType := (others => (others => '0')); 

Row(0)(0) <= 0; 
Row <= ((0, 1, 2), 
        (3, 4, 5), 
         ... 
        (6, 7, 8));

Record​

Allows different types to be combined in one.

Example​

TYPE RGBType IS RECORD 
    R : NATURAL range 0 to 255; 
    G : NATURAL range 0 to 255; 
    B : NATURAL range 0 to 255; 
END RECORD RGBType; 

SIGNAL RGBSig : RGBType := (R => 0, G => 0, B => 0); 

RGBSig.R <= 128; 
RGBSig.G <= 0; 
RGBSig.B <= 255;