Variable Rules

variable_001

This rule checks the indent of variable declarations.

Violation

proc : process () is

variable count : integer;
      variable counter : integer;

begin

Fix

proc : process () is

  variable count : integer;
  variable counter : integer;

begin

variable_002

This rule checks the variable keyword has proper case.

Refer to Configuring Uppercase and Lowercase Rules for more information.

Violation

VARIABLE count : integer;

Fix

variable count : integer;

variable_003

This rule was deprecated and replaced with rules:

• function_015

• package_019

• procedure_010

• architecture_029

variable_004

This rule checks the variable name has proper case.

Refer to Configuring Uppercase and Lowercase Rules for more information.

Violation

variable COUNT : integer;

Fix

variable count : integer;

variable_005

This rule checks there is a single space after the colon.

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

Violation

variable count   :integer;
variable counter :     integer;

Fix

variable count   : integer;
variable counter : integer;

variable_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

variable count: integer;
variable counter : integer;

Fix

variable count : integer;
variable counter : integer;

variable_007

This rule checks for default assignments in variable declarations.

Violation

variable count : integer := 32;

Fix

variable count : integer;

variable_010

The function of this rule has been superseded by the following rules:

• ieee_500

• subtype_002

• type_014

variable_011

This rule checks for consistent capitalization of variable names.

Violation

architecture rtl of entity1 is

  shared variable var1 : std_logic;
  shared variable var2 : std_logic;

begin

  proc_name : process () is

    variable var3 : std_logic;
    variable var4 : std_logic;

  begin

    Var1 <= '0';

    if (VAR2 = '0') then
      vaR3 <= '1';
    elsif (var2 = '1') then
      VAR4 <= '0';
    end if;

  end process proc_name;

end architecture rtl;

Fix

proc_name : process () is

  variable var1 : std_logic;
  variable var2 : std_logic;
  variable var3 : std_logic;
  variable var4 : std_logic;

begin

  var1 <= '0';

  if (var2 = '0') then
    var3 <= '1';
  elsif (var2 = '1') then
    var4 <= '0';
  end if;

end process proc_name;

variable_012

This rule checks for valid prefixes on variable identifiers. The default variable prefix is v_.

Refer to Configuring Prefix and Suffix Rules for more information.

Violation

variable my_var : natural;

Fix

variable v_my_var : natural;

variable_017

This rule checks the structure of variable constraints.

Refer to Configuring Multiline Constraint Rules for more information.

Note

The indenting of multiline variable constraints is handled by the rule variable_400.

Violation

variable v_element : my_record(element1(7 downto 0), element2(3 downto 0));

Fix

variable v_element : my_record(
    element1(7 downto 0),
    element2(3 downto 0)
  );

variable_100

This rule checks for a single space before the identifier.

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

Violation

variable    size : integer;
variable width : integer;

Fix

variable size : integer;
variable width : integer;

variable_101

This rule checks for a single space after the shared keyword.

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

Violation

shared    variable size : integer;

Fix

shared variable size : integer;

variable_102

This rule checks for a single space before the assignment.

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

Violation

variable size : integer      := 32;
variable width : integer:= 256;

Fix

variable size : integer := 32;
variable width : integer := 256;

variable_103

This rule checks for a single space after the assignment.

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

Violation

variable size : integer :=32;
variable width : integer :=     256;

Fix

variable size : integer := 32;
variable width : integer := 256;

variable_400

This rule checks alignment of multiline constraints in variable declarations.

Refer to Configuring Multiline Indent Rules for more information.

Violation

variable v_element : my_record(
         element1(7 downto 0),
element2(3 downto 0)
        );

Fix

variable v_element : my_record(
    element1(7 downto 0),
    element2(3 downto 0)
  );

variable_600

This rule checks for valid suffix on variable identifiers. The default variable suffix is _v.

Refer to Configuring Prefix and Suffix Rules for more information.

Violation

variable my_var : natural;

Fix

variable my_var_v : natural;