Subtype Rules

subtype_001

This rule checks for indentation of the subtype keyword. Proper indentation enhances comprehension.

The indent amount can be controlled by the indentSize attribute on the rule. indentSize defaults to 2.

Violation

architecture rtl of fifo is

     subtype read_size is range 0 to 9;
subtype write_size is range 0 to 9;

begin

Fix

architecture rtl of fifo is

  subtype read_size is range 0 to 9;
  subtype write_size is range 0 to 9;

begin

subtype_002

This rule checks for consistent capitalization of subtype names.

Violation

subtype read_size is range 0 to 9;
subtype write_size is range 0 to 9;

signal read  : READ_SIZE;
signal write : write_size;

constant read_sz  : read_size := 8;
constant write_sz : WRITE_size := 1;

Fix

subtype read_size is range 0 to 9;
subtype write_size is range 0 to 9;

signal read  : read_size;
signal write : write_size;

constant read_sz  : read_size := 8;
constant write_sz : write_size := 1;

subtype_003 (depricated)

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

subtype_004

This rule checks for valid prefixes in subtype identifiers. The default new subtype prefix is st_.

Refer to the section Configuring Prefix and Suffix Rules for information on changing the allowed prefixes.

Violation

subtype my_subtype is range 0 to 9;

Fix

subtype st_my_subtype is range 0 to 9;