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;
Last updated on by Leon Beier