• std_logic_arith (Synopsys)
° Unsigned and signed vector types based on std_logic .
° Overloaded arithmetic operators, conversion functions, and extended functions for these types.
• std_logic_unsigned (Synopsys)
° Unsigned arithmetic operators for std_logic and std_logic_vector
• std_logic_signed (Synopsys)
° Signed arithmetic operators for std_logic and std_logic_vector
• std_logic_misc (Synopsys)
° Supplemental types, subtypes, constants, and functions for the std_logic_1164 package, such as and_reduce and or_reduce .