Constant Rules

constant_001

This rule checks the indent of a constant declaration.

Violation

architecture RTL of FIFO is

constant size : integer := 1;
    constant width : integer := 32

Fix

architecture RTL of FIFO is

  constant size : integer := 1;
  constant width : integer := 32

constant_002

This rule checks the constant keyword has proper case.

Refer to Configuring Uppercase and Lowercase Rules for more information.

Violation

CONSTANT size : integer := 1;

Fix

constant size : integer := 1;

constant_003

This rule was deprecated and replaced with rules: function_015, package_019, procedure_010, architecture_029 and process_037.

constant_004

This rule checks the constant identifier has proper case.

Refer to Configuring Uppercase and Lowercase Rules for more information.

Violation

constant SIZE : integer := 1;

Fix

constant size : integer := 1;

constant_005

This rule checks for a single space after the colon.

Refer to Configuring Whitespace Rules for options on changing the number of whitespaces..

Violation

constant size  :integer := 1;
constant width :     integer := 32;

Fix

constant size  : integer := 1;
constant width : integer := 32;

constant_006

This rule checks for at least a single space before the colon.

Refer to Configuring Whitespace Rules for options on changing the number of whitespaces..

Violation

constant size: integer := 1;
constant width     : integer := 32;

Fix

constant size : integer := 1;
constant width     : integer := 32;

constant_007

This rule checks the := is on the same line at the constant keyword.

Violation

constant size : integer
   := 1;
constant width : integer
   := 32;

Fix

constant size    : integer :=
  1;
constant width   : integer :=
  32

constant_010

This rule checks for a single space before the := keyword in constant declarations. Having a space makes it clearer where the assignment occurs on the line.

Refer to Configuring Whitespace Rules for options on changing the number of whitespaces..

Violation

constant size : integer:= 1;
constant width : integer   := 10;

Fix

constant size : integer := 1;
constant width : integer := 10;

constant_011

The function of this rule has been superseded by the following rules:

ieee_500
subtype_002
type_014

constant_012

This rule checks the alignment of multiline constants that contain arrays.

Refer to Configuring Multiline Indent Rules for more information.

Note

The structure of multiline array constants is handled by the rule constant_016.

Violation

constant rom : romq_type :=
(
         0,
     65535,
     32768
  );

Fix

constant rom : romq_type :=
(
  0,
  65535,
  32768
);

constant_013

This rule checks for consistent capitalization of constant names.

Violation

architecture RTL of ENTITY1 is

  constant c_size  : integer := 5;
  constant c_ones  : std_logic_vector(c_size - 1 downto 0) := (others => '1');
  constant c_zeros : std_logic_vector(c_size - 1 downto 0) := (others => '0');

  signal data : std_logic_vector(c_size - 1 downto 0);

begin

  data <= C_ONES;

  PROC_NAME : process () is
  begin

    data <= C_ones;

    if (sig2 = '0') then
      data <= c_Zeros;
    end if;

  end process PROC_NAME;

end architecture RTL;

Fix

architecture RTL of ENTITY1 is

  constant c_size  : integer := 5;
  constant c_ones  : std_logic_vector(c_size - 1 downto 0) := (others => '1');
  constant c_zeros : std_logic_vector(c_size - 1 downto 0) := (others => '0');

  signal data : std_logic_vector(c_size - 1 downto 0);

begin

  data <= c_ones;

  PROC_NAME : process () is
  begin

    data <= c_ones;

    if (sig2 = '0') then
      data <= c_zeros;
    end if;

  end process PROC_NAME;

end architecture RTL;

constant_014

This rule checks the indent of multiline constants that do not contain arrays.

Refer to Configuring Multiline Indent Rules for more information.

Violation

constant width : integer := a + b +
  c + d;

Fix

constant width : integer := a + b +
                            c + d;

constant_015

This rule checks for valid prefixes on constant identifiers. The default constant prefix is c_.

Refer to Configuring Prefix and Suffix Rules for more information.

Violation

constant my_const : integer;

Fix

constant c_my_const : integer;

constant_016

This rule checks the structure of multiline constants that contain arrays.

Refer to Configuring Array Multiline Structure Rules for more information.

Note

The indenting of multiline array constants is handled by the rule constant_012.

Violation

constant rom : romq_type := (0, 65535, 32768);

Fix

constant rom : romq_type :=
(
  0,
  65535,
  32768
);

constant_017

This rule checks the structure of constant constraints.

Refer to Configuring Multiline Constraint Rules for more information.

Violation

constant con_a : my_record(element1(7 downto 0), element2(3 downto 0));

Fix

constant con_a : my_record(
    element1(7 downto 0),
    element2(3 downto 0)
  );

constant_100

This rule checks for a single space after the := assignment in constant declarations. Having a space makes it clearer where the assignment occurs on the line.

Refer to Configuring Whitespace Rules for options on changing the number of whitespaces..

Violation

constant size : integer :=1;
constant width : t_type :=(

Fix

constant size : integer := 1;
constant width : t_type := (

constant_101

This rule checks for a single space before the identifier.

Refer to Configuring Whitespace Rules for options on changing the number of whitespaces..

Violation

constant    size : integer := 1;
constant width : integer := 32;

Fix

constant size : integer := 1;
constant width : integer := 32;

constant_200

This rule checks for a blank line below a constant declaration unless there is another constant definition.

Refer to Configuring Blank Lines for more information.

Violation

constant width  : integer := 32;
signal   height : integer := 4;

constant width  : integer := 32;
constant height : integer := 4;

Fix

constant width  : integer := 32;
signal   height : integer := 4;

constant width  : integer := 32;
constant height : integer := 4;

constant_400

This rule checks the alignment of assignment keywords in constant declarations.

Refer to Configuring Keyword Alignment Rules for information on changing the configurations.

Violation

constant c_default_values : t_address_en := (
  c_address_control => false,
  c_address_data => true,
  others => false
);

Fix

constant c_default_values : t_address_en := (
  c_address_control => false,
  c_address_data    => true,
  others            => false
);

constant_600

This rule checks for valid suffixes on constant identifiers. The default constant suffix is _c.

Refer to Configuring Prefix and Suffix Rules for more information.

Violation

constant my_const : integer;

Fix

constant my_const_c : integer;