VHDL Type Cast and Conversion Functions
**In ASIC design, do NEVER use integer or natural for signals, use conversion functions instead**
The picture below illustrates how to convert between the most common VHDL types.
For example:
1 signal good_example1 : std_logic_vector(2 downto 0); 2 signal good_example2 : std_logic_vector(3 downto 0); 3 4 good_example1 <= std_logic_vector(to_unsigned(5, good_example1'length)); 5 good_example2 <= std_logic_vector(to_signed(5, good_example2'length));
numeric_std
1 --=========================================================================== 2 -- Numeric array type definitions 3 --=========================================================================== 4 5 type UNSIGNED is array (NATURAL range <> ) of STD_LOGIC; 6 type SIGNED is array (NATURAL range <> ) of STD_LOGIC;