The bit_vector is a one-dimensional array type with elements being of type Bit. The bit_vector type is predefined in the Standard package.

Syntax:

type bit_vector is array (natural range <>) of bit; 

Description:

The bit_vector type is an unconstrained vector. During the declaration the size of a vector is specified.

Assignments to a bit_vector can be done in the same way as in case of any arrays (using single element assignments, concatenation, aggregates, slices or any combination of the previous methods).

The bit_vector is an unresolved type and therefore any object of this type can have only one assignment in an architecture.

Example:

signal Bus : bit_vector(7 downto 0); 
Bus(0) <= '1'; 
Bus <= ('1', others => '0'); 
Bus <= Bus(6 downto 0) & Bus(7); 
Bus <= "01110010";

Notes:

• Logical values for objects of the bit_vector type must be written in double quotes.
• Single elements are of the bit type, therefore all values assigned to single elements are specified in single quotes.

See also:

Bit, Standard Package