12.7 Bit string literals






Definition

bit_string_literal ::=
     base_specifier " bit_value "

base_specifier ::=
    B | O | X

bit_value ::=
     extended_digit { [ underline ] extended_digit }

extended_digit ::=
    digit | letter

Comments

B means binary, O means octal and X means hexadecimal.



Examples

Bit_8: bit_vector(7 downto 0) := B"1111_1111" -- equivalent to "11111111"

Bit_8 : bit_vector(7 downto 0) := X"FF"   -- equivalent to B"1111_1111"

Bit_9 : bit_vector(8 downto 0) := O"777"    -- equivalent to B"111_111_111"

Bit_12: bit_vector(11 downto 0) := X"777"   -- equivalent to B"0111_0111_0111"