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SystemVerilog Reference GuideContents
IntroductionSystemVerilog is a group of extensions to the Verilog HDL originally developed and approved by Accellera and then standardized by IEEE.SystemVerilog extends Verilog into the system-level space and the verification space. This reference guide has been created on the basis of IEEE Standard for SystemVerilog - Unified Hardware Design, Specification, and Verification Language (IEEE Std 1800™-2005) approved in November 2005. Using this Guide |
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A.1 Source text
A.1.1 Library source text
library_text ::= { library_description }
library_description ::= library_declaration
| include_statement
| config_declaration
| ;
library_declaration ::= library library_identifier file_path_spec { , file_path_spec } [ -incdir file_path_spec { , file_path_spec } ] ;
include_statement ::= include file_path_spec ;
A.1.2 SystemVerilog source text
source_text ::= [ timeunits_declaration ] { description }
description ::= module_declaration
| udp_declaration
| interface_declaration
| program_declaration
| package_declaration
| { attribute_instance } package_item
| { attribute_instance } bind_directive
| config_declaration
module_nonansi_header ::= { attribute_instance } module_keyword [ lifetime ] module_identifier [ parameter_port_list ] list_of_ports ;
module_ansi_header ::= { attribute_instance } module_keyword [ lifetime ] module_identifier [ parameter_port_list ] [ list_of_port_declarations ] ;
module_declaration ::=
module_nonansi_header
[ timeunits_declaration ]
{ module_item }
endmodule [ : module_identifier ]
| module_ansi_header
[ timeunits_declaration ]
{ non_port_module_item }
endmodule [ : module_identifier ]
| { attribute_instance } module_keyword [ lifetime ] module_identifier ( .* ) ;
[ timeunits_declaration ]
{ module_item }
endmodule [ : module_identifier ]
| extern module_nonansi_header
| extern module_ansi_header
module_keyword ::= module | macromodule
interface_nonansi_header ::= { attribute_instance } interface [ lifetime ] interface_identifier [ parameter_port_list ] list_of_ports ;
interface_ansi_header ::= {attribute_instance } interface [ lifetime ] interface_identifier [ parameter_port_list ] [ list_of_port_declarations ] ;
interface_declaration ::=
interface_nonansi_header
[ timeunits_declaration ]
{ interface_item }
endinterface [ : interface_identifier ]
| interface_ansi_header
[ timeunits_declaration ]
{ non_port_interface_item }
endinterface [ : interface_identifier ]
| { attribute_instance } interface interface_identifier ( .* ) ;
[ timeunits_declaration ]
{ interface_item }
endinterface [ : interface_identifier ]
| extern interface_nonansi_header
| extern interface_ansi_header
program_nonansi_header ::= { attribute_instance } program [ lifetime ] program_identifier [ parameter_port_list ] list_of_ports ;
program_ansi_header ::= {attribute_instance } program [ lifetime ] program_identifier [ parameter_port_list ] [ list_of_port_declarations ] ;
program_declaration ::=
program_nonansi_header
[ timeunits_declaration ]
{ program_item }
endprogram [ : program_identifier ]
| program_ansi_header
[ timeunits_declaration ]
{ non_port_program_item }
endprogram [ : program_identifier ]
| { attribute_instance } program program_identifier ( .* ) ;
[ timeunits_declaration ]
{ program_item }
endprogram [ : program_identifier ]
| extern program_nonansi_header
| extern program_ansi_header
class_declaration ::= [ virtual ] class [ lifetime ] class_identifier [ parameter_port_list ] [ extends class_type [ ( list_of_arguments ) ] ];
{ class_item }
endclass [ : class_identifier]
package_declaration ::= { attribute_instance } package package_identifier ;
[ timeunits_declaration ] { { attribute_instance } package_item }
endpackage [ : package_identifier ]
timeunits_declaration ::= timeunit time_literal ;
| timeprecision time_literal ;
| timeunit time_literal ;
timeprecision time_literal ;
| timeprecision time_literal ;
timeunit time_literal ;
A.1.3 Module parameters and ports
parameter_port_list ::= # ( list_of_param_assignments { , parameter_port_declaration } )
| # ( parameter_port_declaration { , parameter_port_declaration } )
| #( )
parameter_port_declaration ::= parameter_declaration
| data_type list_of_param_assignments
| type list_of_type_assignments
list_of_ports ::= ( port { , port } )
list_of_port_declarations ::= ( [ { attribute_instance} ansi_port_declaration { , { attribute_instance} ansi_port_declaration } ] )
port_declaration ::= { attribute_instance } inout_declaration
| { attribute_instance } input_declaration
| { attribute_instance } output_declaration
| { attribute_instance } ref_declaration
| { attribute_instance } interface_port_declaration
port ::= [ port_expression ] | . port_identifier ( [ port_expression ] )
port_expression ::= port_reference | { port_reference { , port_reference } }
port_reference ::= port_identifier constant_select
port_direction ::= input | output | inout | ref
net_port_header ::= [ port_direction ] net_port_type
variable_port_header ::= [ port_direction ] variable_port_type
interface_port_header ::= interface_identifier [ . modport_identifier ] | interface [ . modport_identifier ]
ansi_port_declaration ::= [ net_port_header | interface_port_header ] port_identifier { unpacked_dimension }
| [ variable_port_header ] port_identifier { variable_dimension } [ = constant_expression ]
| [ net_port_header | variable_port_header ] . port_identifier ( [ expression ] )
A.1.4 Module items
module_common_item ::= module_or_generate_item_declaration
| interface_instantiation
| program_instantiation
| concurrent_assertion_item
| bind_directive
| continuous_assign
| net_alias
| initial_construct
| final_construct
| always_construct
| loop_generate_construct
| conditional_generate_construct
module_item ::= port_declaration ; | non_port_module_item
module_or_generate_item ::= { attribute_instance } parameter_override
| { attribute_instance } gate_instantiation
| { attribute_instance } udp_instantiation
| { attribute_instance } module_instantiation
| { attribute_instance } module_common_item
module_or_generate_item_declaration ::= package_or_generate_item_declaration
| genvar_declaration
| clocking_declaration
| default clocking clocking_identifier ;
non_port_module_item ::= generate_region
| module_or_generate_item
| specify_block
| { attribute_instance } specparam_declaration
| program_declaration
| module_declaration
| interface_declaration
| timeunits_declaration
parameter_override ::= defparam list_of_defparam_assignments ;
bind_directive ::= bind bind_target_scope [: bind_target_instance_list] bind_instantiation ;
| bind bind_target_instance bind_instantiation ;
bind_target_scope ::= module_identifier | interface_identifier
bind_target_instance ::= hierarchical_identifier constant_bit_select
bind_target_instance_list ::= bind_target_instance { , bind_target_instance }
bind_instantiation ::= program_instantiation
| module_instantiation
| interface_instantiation
A.1.5 Configuration source text
config_declaration ::= config config_identifier ;
design_statement
{ config_rule_statement }
endconfig [ : config_identifier ]
design_statement ::= design { [ library_identifier . ] cell_identifier } ;
config_rule_statement ::= default_clause liblist_clause ;
| inst_clause liblist_clause ;
| inst_clause use_clause ;
| cell_clause liblist_clause ;
| cell_clause use_clause ;
default_clause ::= default
inst_clause ::= instance inst_name
inst_name ::= topmodule_identifier { . instance_identifier }
cell_clause ::= cell [ library_identifier . ] cell_identifier
liblist_clause ::= liblist {library_identifier}
use_clause ::= use [ library_identifier . ] cell_identifier [ : config ]
A.1.6 Interface items
interface_or_generate_item ::= { attribute_instance } module_common_item
| { attribute_instance } modport_declaration
| { attribute_instance } extern_tf_declaration
extern_tf_declaration ::= extern method_prototype ;
| extern forkjoin task_prototype ;
interface_item ::= port_declaration ;
| non_port_interface_item
non_port_interface_item ::= generate_region
| interface_or_generate_item
| program_declaration
| interface_declaration
| timeunits_declaration
A.1.7 Program items
program_item ::= port_declaration ;
| non_port_program_item
non_port_program_item ::= { attribute_instance } continuous_assign
| { attribute_instance } module_or_generate_item_declaration
| { attribute_instance } initial_construct
| { attribute_instance } final_construct
| { attribute_instance } concurrent_assertion_item
| { attribute_instance } timeunits_declaration
| program_generate_item
program_generate_item ::= loop_generate_construct
| conditional_generate_construct
| generate_region
A.1.8 Class items
class_item ::= { attribute_instance } class_property
| { attribute_instance } class_method
| { attribute_instance } class_constraint
| { attribute_instance } class_declaration
| { attribute_instance } timeunits_declaration
| { attribute_instance } covergroup_declaration
| ;
class_property ::= { property_qualifier } data_declaration
| const { class_item_qualifier } data_type const_identifier [ = constant_expression ] ;
class_method ::= { method_qualifier } task_declaration
| { method_qualifier } function_declaration
| extern { method_qualifier } method_prototype ;
| { method_qualifier } class_constructor_declaration
| extern { method_qualifier } class_constructor_prototype
class_constructor_prototype ::= function new ( [ tf_port_list ] ) ;
class_constraint ::= constraint_prototype | constraint_declaration
class_item_qualifier ::= static | protected | local
property_qualifier ::= random_qualifier | class_item_qualifier
random_qualifier ::= rand | randc
method_qualifier ::= virtual | class_item_qualifier
method_prototype ::= task_prototype | function_prototype
class_constructor_declaration ::= function [ class_scope ] new [ ( [ tf_port_list ] ) ] ;
{ block_item_declaration }
[ super . new [ ( list_of_arguments ) ] ; ]
{ function_statement_or_null }
endfunction [ : new ]
A.1.9 Constraints
constraint_declaration ::= [ static ] constraint constraint_identifier constraint_block
constraint_block ::= { { constraint_block_item } }
constraint_block_item ::= solve identifier_list before identifier_list ;
| constraint_expression
constraint_expression ::= expression_or_dist ;
| expression -> constraint_set
| if ( expression ) constraint_set [ else constraint_set ]
| foreach ( array_identifier [ loop_variables ] ) constraint_set
constraint_set ::= constraint_expression | { { constraint_expression } }
dist_list ::= dist_item { , dist_item }
dist_item ::= value_range [ dist_weight ]
dist_weight ::= := expression | :/ expression
constraint_prototype ::= [ static ] constraint constraint_identifier ;
extern_constraint_declaration ::= [ static ] constraint class_scope constraint_identifier constraint_block
identifier_list ::= identifier { , identifier }
A.1.10 Package items
package_item ::= package_or_generate_item_declaration
| anonymous_program
| timeunits_declaration
package_or_generate_item_declaration ::= net_declaration
| data_declaration
| task_declaration
| function_declaration
| dpi_import_export
| extern_constraint_declaration
| class_declaration
| class_constructor_declaration
| parameter_declaration ;
| local_parameter_declaration
| covergroup_declaration
| overload_declaration
| concurrent_assertion_item_declaration
| ;
anonymous_program ::= program ; { anonymous_program_item } endprogram
anonymous_program_item ::= task_declaration
| function_declaration
| class_declaration
| covergroup_declaration
| class_constructor_declaration
| ;
A.2 Declarations
A.2.1 Declaration types
A.2.1.1 Module parameter declarations
local_parameter_declaration ::= localparam data_type_or_implicit list_of_param_assignments ;
| localparam type list_of_type_assignments ;
parameter_declaration ::= parameter data_type_or_implicit list_of_param_assignments
| parameter type list_of_type_assignments
specparam_declaration ::= specparam [ packed_dimension ] list_of_specparam_assignments ;
A.2.1.2 Port declarations
inout_declaration ::= inout net_port_type list_of_port_identifiers
input_declaration ::= input net_port_type list_of_port_identifiers
| input variable_port_type list_of_variable_identifiers
output_declaration ::= output net_port_type list_of_port_identifiers
| output variable_port_type list_of_variable_port_identifiers
interface_port_declaration ::= interface_identifier list_of_interface_identifiers
| interface_identifier . modport_identifier list_of_interface_identifiers
ref_declaration ::= ref variable_port_type list_of_port_identifiers
A.2.1.3 Type declarations
data_declaration ::= [ const ] [ var ] [ lifetime ] data_type_or_implicit list_of_variable_decl_assignments ;
| type_declaration
| package_import_declaration
| virtual_interface_declaration
package_import_declaration ::= import package_import_item { , package_import_item } ;
package_import_item ::= package_identifier :: identifier | package_identifier :: *
genvar_declaration ::= genvar list_of_genvar_identifiers ;
net_declaration ::= net_type [ drive_strength | charge_strength ] [ vectored | scalared ] data_type_or_implicit [ delay3 ] list_of_net_decl_assignments ;
type_declaration ::= typedef data_type type_identifier { variable_dimension } ;
| typedef interface_instance_identifier . type_identifier type_identifier ;
| typedef [ enum | struct | union | class ] type_identifier ;
lifetime ::= static | automatic
A.2.2 Declaration data types
A.2.2.1 Net and variable types
casting_type ::= simple_type | constant_primary | signing
data_type ::= integer_vector_type [ signing ] { packed_dimension }
| integer_atom_type [ signing ]
| non_integer_type
| struct_union [ packed [ signing ] ] { struct_union_member { struct_union_member } }{ packed_dimension }
| enum [ enum_base_type ] { enum_name_declaration { , enum_name_declaration } }
| string
| chandle
| virtual [ interface ] interface_identifier
| [ class_scope | package_scope ] type_identifier { packed_dimension }
| class_type
| event
| ps_covergroup_identifier
| type_reference
data_type_or_implicit ::= data_type | [ signing ] { packed_dimension }
enum_base_type ::= integer_atom_type [ signing ]
| integer_vector_type [ signing ] [ packed_dimension ]
| type_identifier [ packed_dimension ]
enum_name_declaration ::= enum_identifier [ [ integral_number [ : integral_number ] ] ] [ = constant_expression ]
class_scope ::= class_type ::
class_type ::= ps_class_identifier [ parameter_value_assignment ] { :: class_identifier [ parameter_value_assignment ] }
integer_type ::= integer_vector_type | integer_atom_type
integer_atom_type ::= byte | shortint | int | longint | integer | time
integer_vector_type ::= bit | logic | reg
non_integer_type ::= shortreal | real | realtime
net_type ::= supply0 | supply1 | tri | triand | trior | trireg| tri0 | tri1 | uwire | wire | wand | wor
net_port_type ::= [ net_type ] data_type_or_implicit
variable_port_type ::= var_data_type
var_data_type ::= data_type | var data_type_or_implicit
signing ::= signed | unsigned
simple_type ::= integer_type | non_integer_type | ps_type_identifier | ps_parameter_identifier
struct_union_member ::= { attribute_instance } [random_qualifier] data_type_or_void list_of_variable_decl_assignments ;
data_type_or_void ::= data_type | void
struct_union ::= struct | union [ tagged ]
type_reference ::= type ( expression ) | type ( data_type )
A.2.2.2 Strengths
drive_strength ::= ( strength0 , strength1 )
| ( strength1 , strength0 )
| ( strength0 , highz1 )
| ( strength1 , highz0 )
| ( highz0 , strength1 )
| ( highz1 , strength0 )
strength0 ::= supply0 | strong0 | pull0 | weak0
strength1 ::= supply1 | strong1 | pull1 | weak1
charge_strength ::= ( small ) | ( medium ) | ( large )
A.2.2.3 Delays
delay3 ::= # delay_value | # ( mintypmax_expression [ , mintypmax_expression [ , mintypmax_expression ] ] )
delay2 ::= # delay_value | # ( mintypmax_expression [ , mintypmax_expression ] )
delay_value ::= unsigned_number
| real_number
| ps_identifier
| time_literal
A.2.3 Declaration lists
list_of_defparam_assignments ::= defparam_assignment { , defparam_assignment }
list_of_genvar_identifiers ::= genvar_identifier { , genvar_identifier }
list_of_interface_identifiers ::= interface_identifier { unpacked_dimension } { , interface_identifier { unpacked_dimension } }
list_of_net_decl_assignments ::= net_decl_assignment { , net_decl_assignment }
list_of_param_assignments ::= param_assignment { , param_assignment }
list_of_port_identifiers ::= port_identifier { unpacked_dimension } { , port_identifier { unpacked_dimension } }
list_of_udp_port_identifiers ::= port_identifier { , port_identifier }
list_of_specparam_assignments ::= specparam_assignment { , specparam_assignment }
list_of_tf_variable_identifiers ::= port_identifier { variable_dimension } [ = expression ] { , port_identifier { variable_dimension } [ = expression ] }
list_of_type_assignments ::= type_assignment { , type_assignment }
list_of_variable_decl_assignments ::= variable_decl_assignment { , variable_decl_assignment }
list_of_variable_identifiers ::= variable_identifier { variable_dimension } { , variable_identifier { variable_dimension } }
list_of_variable_port_identifiers ::= port_identifier { variable_dimension } [ = constant_expression ] { , port_identifier { variable_dimension } [ = constant_expression ] }
list_of_virtual_interface_decl ::= variable_identifier [ = interface_instance_identifier ] { , variable_identifier [ = interface_instance_identifier ] }
A.2.4 Declaration assignments
defparam_assignment ::= hierarchical_parameter_identifier = constant_mintypmax_expression
net_decl_assignment ::= net_identifier { unpacked_dimension } [ = expression ]
param_assignment ::= parameter_identifier { unpacked_dimension } = constant_param_expression
specparam_assignment ::= specparam_identifier = constant_mintypmax_expression | pulse_control_specparam
type_assignment ::= type_identifier = data_type
pulse_control_specparam ::= PATHPULSE$ = ( reject_limit_value [ , error_limit_value ] )
| PATHPULSE$specify_input_terminal_descriptor$specify_output_terminal_descriptor = ( reject_limit_value [ , error_limit_value ] )
error_limit_value ::= limit_value
reject_limit_value ::= limit_value
limit_value ::= constant_mintypmax_expression
variable_decl_assignment ::= variable_identifier { variable_dimension } [ = expression ]
| dynamic_array_variable_identifier [ ] [ = dynamic_array_new ]
| class_variable_identifier [ = class_new ]
| [ covergroup_variable_identifier ] = new [ ( list_of_arguments ) ]
class_new ::= new [ ( list_of_arguments ) | expression ]
dynamic_array_new ::= new [ expression ] [ ( expression ) ]
A.2.5 Declaration ranges
unpacked_dimension ::= [ constant_range ] | [ constant_expression ]
packed_dimension ::= [ constant_range ] | unsized_dimension
associative_dimension ::= [ data_type ] | [ * ]
variable_dimension ::= unsized_dimension
| unpacked_dimension
| associative_dimension
| queue_dimension
queue_dimension ::= [ $ [ : constant_expression ] ]
unsized_dimension ::= [ ]
A.2.6 Function declarations
function_data_type ::= data_type | void
function_data_type_or_implicit ::= function_data_type | [ signing ] { packed_dimension }
function_declaration ::= function [ lifetime ] function_body_declaration
function_body_declaration ::= function_data_type_or_implicit
[ interface_identifier . | class_scope ] function_identifier ;
{ tf_item_declaration }
{ function_statement_or_null }
endfunction [ : function_identifier ]
| function_data_type_or_implicit
[ interface_identifier . | class_scope ] function_identifier ( [ tf_port_list ] ) ;
{ block_item_declaration }
{ function_statement_or_null }
endfunction [ : function_identifier ]
function_prototype ::= function function_data_type function_identifier ( [ tf_port_list ] )
dpi_import_export ::= import dpi_spec_string [ dpi_function_import_property ] [ c_identifier = ] dpi_function_proto ;
| import dpi_spec_string [ dpi_task_import_property ] [ c_identifier = ] dpi_task_proto ;
| export dpi_spec_string [ c_identifier = ] function function_identifier ;
| export dpi_spec_string [ c_identifier = ] task task_identifier ;
dpi_spec_string ::= "DPI-C" | "DPI"
dpi_function_import_property ::= context | pure
dpi_task_import_property ::= context
dpi_function_proto ::= function_prototype
dpi_task_proto ::= task_prototype
A.2.7 Task declarations
task_declaration ::= task [ lifetime ] task_body_declaration
task_body_declaration ::= [ interface_identifier . | class_scope ] task_identifier ;
{ tf_item_declaration }
{ statement_or_null }
endtask [ : task_identifier ]
| [ interface_identifier . | class_scope ] task_identifier ( [ tf_port_list ] ) ;
{ block_item_declaration }
{ statement_or_null }
endtask [ : task_identifier ]
tf_item_declaration ::= block_item_declaration | tf_port_declaration
tf_port_list ::= tf_port_item { , tf_port_item }
tf_port_item ::= { attribute_instance } [ tf_port_direction ] [ var ] data_type_or_implicit [ port_identifier { variable_dimension } [ = expression ] ]
tf_port_direction ::= port_direction | const ref
tf_port_declaration ::= { attribute_instance } tf_port_direction [ var ] data_type_or_implicit list_of_tf_variable_identifiers ;
task_prototype ::= task task_identifier ( [ tf_port_list ] )
A.2.8 Block item declarations
block_item_declaration ::= { attribute_instance } data_declaration
| { attribute_instance } local_parameter_declaration
| { attribute_instance } parameter_declaration ;
| { attribute_instance } overload_declaration
overload_declaration ::= bind overload_operator function data_type function_identifier ( overload_proto_formals ) ;
overload_operator ::= + | ++ | - | -- | * | ** | / | % | == | != | < | <= | > | >= | =
overload_proto_formals ::= data_type {, data_type}
A.2.9 Interface declarations
virtual_interface_declaration ::= virtual [ interface ] interface_identifier list_of_virtual_interface_decl ;
modport_declaration ::= modport modport_item { , modport_item } ;
modport_item ::= modport_identifier ( modport_ports_declaration { , modport_ports_declaration } )
modport_ports_declaration ::= { attribute_instance } modport_simple_ports_declaration
| { attribute_instance } modport_tf_ports_declaration
| { attribute_instance } modport_clocking_declaration
modport_clocking_declaration ::= clocking clocking_identifier
modport_simple_ports_declaration ::= port_direction modport_simple_port { , modport_simple_port }
modport_simple_port ::= port_identifier | . port_identifier ( [ expression ] )
modport_tf_ports_declaration ::= import_export modport_tf_port { , modport_tf_port }
modport_tf_port ::= method_prototype | tf_identifier
import_export ::= import | export
A.2.10 Assertion declarations
concurrent_assertion_item ::= [ block_identifier : ] concurrent_assertion_statement
concurrent_assertion_statement ::= assert_property_statement
| assume_property_statement
| cover_property_statement
assert_property_statement::= assert property ( property_spec ) action_block
assume_property_statement::= assume property ( property_spec ) ;
cover_property_statement::= cover property ( property_spec ) statement_or_null
expect_property_statement ::= expect ( property_spec ) action_block
property_instance ::= ps_property_identifier [ ( [ list_of_arguments ] ) ]
concurrent_assertion_item_declaration ::= property_declaration | sequence_declaration
property_declaration ::= property property_identifier [ ( [ tf_port_list ] ) ] ;
{ assertion_variable_declaration }
property_spec ;
endproperty [ : property_identifier ]
property_spec ::= [clocking_event ] [ disable iff ( expression_or_dist ) ] property_expr
property_expr ::= sequence_expr
| ( property_expr )
| not property_expr
| property_expr or property_expr
| property_expr and property_expr
| sequence_expr |-> property_expr
| sequence_expr |=> property_expr
| if ( expression_or_dist ) property_expr [ else property_expr ]
| property_instance
| clocking_event property_expr
sequence_declaration ::= sequence sequence_identifier [ ( [ tf_port_list ] ) ] ;
{ assertion_variable_declaration }
sequence_expr ;
endsequence [ : sequence_identifier ]
sequence_expr ::= cycle_delay_range sequence_expr { cycle_delay_range sequence_expr }
| sequence_expr cycle_delay_range sequence_expr { cycle_delay_range sequence_expr }
| expression_or_dist [ boolean_abbrev ]
| ( expression_or_dist {, sequence_match_item } ) [ boolean_abbrev ]
| sequence_instance [ sequence_abbrev ]
| ( sequence_expr {, sequence_match_item } ) [ sequence_abbrev ]
| sequence_expr and sequence_expr
| sequence_expr intersect sequence_expr
| sequence_expr or sequence_expr
| first_match ( sequence_expr {, sequence_match_item} )
| expression_or_dist throughout sequence_expr
| sequence_expr within sequence_expr
| clocking_event sequence_expr
cycle_delay_range ::= ## integral_number
| ## identifier
| ## ( constant_expression )
| ## [ cycle_delay_const_range_expression ]
sequence_method_call ::= sequence_instance . method_identifier
sequence_match_item ::= operator_assignment
| inc_or_dec_expression
| subroutine_call
sequence_instance ::= ps_sequence_identifier [ ( [ list_of_arguments ] ) ]
formal_list_item ::= formal_identifier [ = actual_arg_expr ]
list_of_formals ::= formal_list_item { , formal_list_item }
actual_arg_expr ::= event_expression | $
boolean_abbrev ::= consecutive_repetition
| non_consecutive_repetition
| goto_repetition
sequence_abbrev ::= consecutive_repetition
consecutive_repetition ::= [* const_or_range_expression ]
non_consecutive_repetition ::= [= const_or_range_expression ]
goto_repetition ::= [-> const_or_range_expression ]
const_or_range_expression ::= constant_expression
| cycle_delay_const_range_expression
cycle_delay_const_range_expression ::= constant_expression : constant_expression
| constant_expression : $
expression_or_dist ::= expression [ dist { dist_list } ]
assertion_variable_declaration ::= var_data_type list_of_variable_identifiers ;
A.2.11 Covergroup declarations
covergroup_declaration ::= covergroup covergroup_identifier [ ( [ tf_port_list ] ) ] [ coverage_event ] ;
{ coverage_spec_or_option }
endgroup [ : covergroup_identifier ]
coverage_spec_or_option ::= {attribute_instance} coverage_spec | {attribute_instance} coverage_option ;
coverage_option ::= option.member_identifier = expression | type_option.member_identifier = expression
coverage_spec ::= cover_point | cover_cross
coverage_event ::= clocking_event | @@( block_event_expression )
block_event_expression ::= block_event_expression or block_event_expression
| begin hierarchical_btf_identifier
| end hierarchical_btf_identifier
hierarchical_btf_identifier ::= hierarchical_tf_identifier
| hierarchical_block_identifier
| hierarchical_identifier [ class_scope ] method_identifier
cover_point ::= [ cover_point_identifier : ] coverpoint expression [ iff ( expression ) ] bins_or_empty
bins_or_empty ::= { {attribute_instance} { bins_or_options ; } }
| ;
bins_or_options ::= coverage_option
| [ wildcard ] bins_keyword bin_identifier [ [ [ expression ] ] ] = { open_range_list } [ iff ( expression ) ]
| [ wildcard ] bins_keyword bin_identifier [ [ ] ] = trans_list [ iff ( expression ) ]
| bins_keyword bin_identifier [ [ [ expression ] ] ] = default [ iff ( expression ) ]
| bins_keyword bin_identifier = default sequence [ iff ( expression ) ]
bins_keyword::= bins | illegal_bins | ignore_bins
range_list ::= value_range { , value_range }
trans_list ::= ( trans_set ) { , ( trans_set ) }
trans_set ::= trans_range_list { => trans_range_list }
trans_range_list ::= trans_item
| trans_item [ [* repeat_range ] ]
| trans_item [ [-> repeat_range ] ]
| trans_item [ [= repeat_range ] ]
trans_item ::= range_list
repeat_range ::= expression
| expression : expression
cover_cross ::= [ cover_point_identifier : ] cross list_of_coverpoints [ iff ( expression ) ] select_bins_or_empty
list_of_coverpoints ::= cross_item , cross_item { , cross_item }
cross_item ::= cover_point_identifier | variable_identifier
select_bins_or_empty ::= { { bins_selection_or_option ; } }
| ;
bins_selection_or_option ::= { attribute_instance } coverage_option
| { attribute_instance } bins_selection
bins_selection ::= bins_keyword bin_identifier = select_expression [ iff ( expression ) ]
select_expression ::= select_condition
| ! select_condition
| select_expression && select_expression
| select_expression || select_expression
| ( select_expression )
select_condition ::= binsof ( bins_expression ) [ intersect { open_range_list } ]
bins_expression ::= variable_identifier | cover_point_identifier [ . bins_identifier ]
open_range_list ::= open_value_range { , open_value_range }
open_value_range ::= value_range
A.3 Primitive instances
A.3.1 Primitive instantiation and instances
gate_instantiation ::= cmos_switchtype [delay3] cmos_switch_instance { , cmos_switch_instance } ;
| enable_gatetype [drive_strength] [delay3] enable_gate_instance { , enable_gate_instance } ;
| mos_switchtype [delay3] mos_switch_instance { , mos_switch_instance } ;
| n_input_gatetype [drive_strength] [delay2] n_input_gate_instance { , n_input_gate_instance } ;
| n_output_gatetype [drive_strength] [delay2] n_output_gate_instance { , n_output_gate_instance } ;
| pass_en_switchtype [delay2] pass_enable_switch_instance { , pass_enable_switch_instance } ;
| pass_switchtype pass_switch_instance { , pass_switch_instance } ;
| pulldown [pulldown_strength] pull_gate_instance { , pull_gate_instance } ;
| pullup [pullup_strength] pull_gate_instance { , pull_gate_instance } ;
cmos_switch_instance ::= [ name_of_instance ] ( output_terminal , input_terminal , ncontrol_terminal , pcontrol_terminal )
enable_gate_instance ::= [ name_of_instance ] ( output_terminal , input_terminal , enable_terminal )
mos_switch_instance ::= [ name_of_instance ] ( output_terminal , input_terminal , enable_terminal )
n_input_gate_instance ::= [ name_of_instance ] ( output_terminal , input_terminal { , input_terminal } )
n_output_gate_instance ::= [ name_of_instance ] ( output_terminal { , output_terminal } , input_terminal )
pass_switch_instance ::= [ name_of_instance ] ( inout_terminal , inout_terminal )
pass_enable_switch_instance ::= [ name_of_instance ] ( inout_terminal , inout_terminal , enable_terminal )
pull_gate_instance ::= [ name_of_instance ] ( output_terminal )
A.3.2 Primitive strengths
pulldown_strength ::= ( strength0 , strength1 )
| ( strength1 , strength0 )
| ( strength0 )
pullup_strength ::= ( strength0 , strength1 )
| ( strength1 , strength0 )
| ( strength1 )
A.3.3 Primitive terminals
enable_terminal ::= expression
inout_terminal ::= net_lvalue
input_terminal ::= expression
ncontrol_terminal ::= expression
output_terminal ::= net_lvalue
pcontrol_terminal ::= expression
A.3.4 Primitive gate and switch types
cmos_switchtype ::= cmos | rcmos
enable_gatetype ::= bufif0 | bufif1 | notif0 | notif1
mos_switchtype ::= nmos | pmos | rnmos | rpmos
n_input_gatetype ::= and | nand | or | nor | xor | xnor
n_output_gatetype ::= buf | not
pass_en_switchtype ::= tranif0 | tranif1 | rtranif1 | rtranif0
pass_switchtype ::= tran | rtran
A.4 Module, interface and generated instantiation
A.4.1 Instantiation
A.4.1.1 Module instantiation
module_instantiation ::= module_identifier [ parameter_value_assignment ] hierarchical_instance { , hierarchical_instance } ;
parameter_value_assignment ::= # ( [ list_of_parameter_assignments ] )
list_of_parameter_assignments ::= ordered_parameter_assignment { , ordered_parameter_assignment }
| named_parameter_assignment { , named_parameter_assignment }
ordered_parameter_assignment ::= param_expression
named_parameter_assignment ::= . parameter_identifier ( [ param_expression ] )
hierarchical_instance ::= name_of_instance ( [ list_of_port_connections ] )
name_of_instance ::= instance_identifier { unpacked_dimension }
list_of_port_connections ::= ordered_port_connection { , ordered_port_connection }
| named_port_connection { , named_port_connection }
ordered_port_connection ::= { attribute_instance } [ expression ]
named_port_connection ::= { attribute_instance } . port_identifier [ ( [ expression ] ) ]
| { attribute_instance } .*
A.4.1.2 Interface instantiation
interface_instantiation ::= interface_identifier [ parameter_value_assignment ] hierarchical_instance { , hierarchical_instance } ;
A.4.1.3 Program instantiation
program_instantiation ::= program_identifier [ parameter_value_assignment ] hierarchical_instance { , hierarchical_instance } ;
A.4.2 Generated instantiation
module_or_interface_or_generate_item ::= module_or_generate_item | interface_or_generate_item
generate_region ::= generate { module_or_interface_or_generate_item } endgenerate
loop_generate_construct ::= for ( genvar_initialization ; genvar_expression ; genvar_iteration )
generate_block
genvar_initialization ::= [ genvar ] genvar_identifier = constant_expression
genvar_iteration ::= genvar_identifier assignment_operator genvar_expression
| inc_or_dec_operator genvar_identifier
| genvar_identifier inc_or_dec_operator
conditional_generate_construct ::= if_generate_construct | case_generate_construct
if_generate_construct ::= if ( constant_expression ) generate_block_or_null [ else generate_block_or_null ]
case_generate_construct ::= case ( constant_expression ) case_generate_item { case_generate_item } endcase
case_generate_item ::= constant_expression { , constant_expression } : generate_block_or_null
| default [ : ] generate_block_or_null
generate_block ::= module_or_interface_or_generate_item
| [ generate_block_identifier : ] begin [ : generate_block_identifier ]
{ module_or_interface_or_generate_item }
end [ : generate_block_identifier ]
generate_block_or_null ::= generate_block | ;
A.5 UDP declaration and instantiation
A.5.1 UDP declaration
udp_nonansi_declaration ::= { attribute_instance } primitive udp_identifier ( udp_port_list ) ;
udp_ansi_declaration ::= { attribute_instance } primitive udp_identifier ( udp_declaration_port_list ) ;
udp_declaration ::= udp_nonansi_declaration udp_port_declaration { udp_port_declaration }
udp_body
endprimitive [ : udp_identifier ]
| udp_ansi_declaration
udp_body
endprimitive [ : udp_identifier ]
| extern udp_nonansi_declaration
| extern udp_ansi_declaration
| { attribute_instance } primitive udp_identifier ( .* ) ;
{ udp_port_declaration }
udp_body
endprimitive [ : udp_identifier ]
A.5.2 UDP ports
udp_port_list ::= output_port_identifier , input_port_identifier { , input_port_identifier }
udp_declaration_port_list ::= udp_output_declaration , udp_input_declaration { , udp_input_declaration }
udp_port_declaration ::= udp_output_declaration ;
| udp_input_declaration ;
| udp_reg_declaration ;
udp_output_declaration ::= { attribute_instance } output port_identifier
| { attribute_instance } output reg port_identifier [ = constant_expression ]
udp_input_declaration ::= { attribute_instance } input list_of_udp_port_identifiers
udp_reg_declaration ::= { attribute_instance } reg variable_identifier
A.5.3 UDP body
udp_body ::= combinational_body | sequential_body
combinational_body ::= table combinational_entry { combinational_entry } endtable
combinational_entry ::= level_input_list : output_symbol ;
sequential_body ::= [ udp_initial_statement ] table sequential_entry { sequential_entry } endtable
udp_initial_statement ::= initial output_port_identifier = init_val ;
init_val ::= 1'b0 | 1'b1 | 1'bx | 1'bX | 1'B0 | 1'B1 | 1'Bx | 1'BX | 1 | 0
sequential_entry ::= seq_input_list : current_state : next_state ;
seq_input_list ::= level_input_list | edge_input_list
level_input_list ::= level_symbol { level_symbol }
edge_input_list ::= { level_symbol } edge_indicator { level_symbol }
edge_indicator ::= ( level_symbol level_symbol ) | edge_symbol
current_state ::= level_symbol
next_state ::= output_symbol | -
output_symbol ::= 0 | 1 | x | X
level_symbol ::= 0 | 1 | x | X | ? | b | B
edge_symbol ::= r | R | f | F | p | P | n | N | *
A.5.4 UDP instantiation
udp_instantiation ::= udp_identifier [ drive_strength ] [ delay2 ] udp_instance { , udp_instance } ;
udp_instance ::= [ name_of_instance ] ( output_terminal , input_terminal { , input_terminal } )
A.6 Behavioral statements
A.6.1 Continuous assignment and net alias statements
continuous_assign ::= assign [ drive_strength ] [ delay3 ] list_of_net_assignments ;
| assign [ delay_control ] list_of_variable_assignments ;
list_of_net_assignments ::= net_assignment { , net_assignment }
list_of_variable_assignments ::= variable_assignment { , variable_assignment }
net_alias ::= alias net_lvalue = net_lvalue { = net_lvalue } ;
net_assignment ::= net_lvalue = expression
A.6.2 Procedural blocks and assignments
initial_construct ::= initial statement_or_null
always_construct ::= always_keyword statement
always_keyword ::= always | always_comb | always_latch | always_ff
final_construct ::= final function_statement
blocking_assignment ::= variable_lvalue = delay_or_event_control expression
| hierarchical_dynamic_array_variable_identifier = dynamic_array_new
| [ implicit_class_handle . | class_scope | package_scope ] hierarchical_variable_identifier
select = class_new | operator_assignment
operator_assignment ::= variable_lvalue assignment_operator expression
assignment_operator ::= = | += | -= | *= | /= | %= | &= | |= | ^= | <<= | >>= | <<<= | >>>=
nonblocking_assignment ::= variable_lvalue <= [ delay_or_event_control ] expression
procedural_continuous_assignment ::= assign variable_assignment
| deassign variable_lvalue
| force variable_assignment
| force net_assignment
| release variable_lvalue
| release net_lvalue
variable_assignment ::= variable_lvalue = expression
A.6.3 Parallel and sequential blocks
action_block ::= statement_or_null
| [ statement ] else statement_or_null
seq_block ::= begin [ : block_identifier ]
{ block_item_declaration }
{ statement_or_null }
end [ : block_identifier ]
par_block ::= fork [ : block_identifier ]
{ block_item_declaration }
{ statement_or_null }
join_keyword [ : block_identifier ]
join_keyword ::= join | join_any | join_none
A.6.4 Statements
statement_or_null ::= statement | { attribute_instance } ;
statement ::= [ block_identifier : ] { attribute_instance } statement_item
statement_item ::= blocking_assignment ;
| nonblocking_assignment ;
| procedural_continuous_assignment ;
| case_statement
| conditional_statement
| inc_or_dec_expression ;
| subroutine_call_statement
| disable_statement
| event_trigger
| loop_statement
| jump_statement
| par_block
| procedural_timing_control_statement
| seq_block
| wait_statement
| procedural_assertion_statement
| clocking_drive ;
| randsequence_statement
| randcase_statement
| expect_property_statement
function_statement ::= statement
function_statement_or_null ::= function_statement | { attribute_instance } ;
variable_identifier_list ::= variable_identifier { , variable_identifier }
A.6.5 Timing control statements
procedural_timing_control_statement ::= procedural_timing_control statement_or_null
delay_or_event_control ::= delay_control
| event_control
| repeat ( expression ) event_control
delay_control ::= # delay_value
| # ( mintypmax_expression )
event_control ::= @ hierarchical_event_identifier
| @ ( event_expression )
| @*
| @ (*)
| @ sequence_instance
event_expression ::= [ edge_identifier ] expression [ iff expression ]
| sequence_instance [ iff expression ]
| event_expression or event_expression
| event_expression , event_expression
procedural_timing_control ::= delay_control
| event_control
| cycle_delay
jump_statement ::= return [ expression ] ;
| break ;
| continue ;
wait_statement ::= wait ( expression ) statement_or_null
| wait fork ;
| wait_order ( hierarchical_identifier { , hierarchical_identifier } ) action_block
event_trigger ::= -> hierarchical_event_identifier ;
| ->> [ delay_or_event_control ] hierarchical_event_identifier ;
disable_statement ::= disable hierarchical_task_identifier ;
| disable hierarchical_block_identifier ;
| disable fork ;
A.6.6 Conditional statements
conditional_statement ::= if ( cond_predicate ) statement_or_null [ else statement_or_null ]
| unique_priority_if_statement
unique_priority_if_statement ::= [ unique_priority ] if ( cond_predicate ) statement_or_null
{ else if ( cond_predicate ) statement_or_null }
[ else statement_or_null ]
unique_priority ::= unique | priority
cond_predicate ::= expression_or_cond_pattern { &&& expression_or_cond_pattern }
expression_or_cond_pattern ::= expression | cond_pattern
cond_pattern ::= expression matches pattern
A.6.7 case statements
case_statement ::= [ unique_priority ] case_keyword ( expression ) case_item { case_item } endcase
| [ unique_priority ] case_keyword ( expression ) matches case_pattern_item { case_pattern_item } endcase
| [ unique_priority ] case ( expression ) inside case_inside_item { case_inside_item } endcase
case_keyword ::= case | casez | casex
case_item ::= expression { , expression } : statement_or_null
| default [ : ] statement_or_null
case_pattern_item ::= pattern [ &&& expression ] : statement_or_null
| default [ : ] statement_or_null
case_inside_item ::= open_range_list : statement_or_null
| default [ : ] statement_or_null
randcase_statement ::= randcase randcase_item { randcase_item } endcase
randcase_item ::= expression : statement_or_null
A.6.7.1 Patterns
pattern ::= . variable_identifier
| .*
| constant_expression
| tagged member_identifier [ pattern ]
| '{ pattern { , pattern } }
| '{ member_identifier : pattern { , member_identifier : pattern } }
assignment_pattern ::= '{ expression { , expression } }
| '{ structure_pattern_key : expression { , structure_pattern_key : expression } }
| '{ array_pattern_key : expression { , array_pattern_key : expression } }
| '{ constant_expression { expression { , expression } } }
structure_pattern_key ::= member_identifier | assignment_pattern_key
array_pattern_key ::= constant_expression | assignment_pattern_key
assignment_pattern_key ::= simple_type | default
assignment_pattern_expression ::= [ assignment_pattern_expression_type ] assignment_pattern
assignment_pattern_expression_type ::= ps_type_identifier | ps_parameter_identifier | integer_atom_type
constant_assignment_pattern_expression ::= assignment_pattern_expression
assignment_pattern_net_lvalue ::= '{ net_lvalue {, net_lvalue } }
assignment_pattern_variable_lvalue ::= '{ variable_lvalue {, variable_lvalue } }
A.6.8 Looping statements
loop_statement ::= forever statement_or_null
| repeat ( expression ) statement_or_null
| while ( expression ) statement_or_null
| for ( for_initialization ; expression ; for_step )
statement_or_null
| do statement_or_null while ( expression ) ;
| foreach ( array_identifier [ loop_variables ] ) statement
for_initialization ::= list_of_variable_assignments
| for_variable_declaration { , for_variable_declaration }
for_variable_declaration ::= data_type variable_identifier = expression { , variable_identifier = expression }
for_step ::= for_step_assignment { , for_step_assignment }
for_step_assignment ::= operator_assignment
| inc_or_dec_expression
| function_subroutine_call
loop_variables ::= [ index_variable_identifier ] { , [ index_variable_identifier ] }
A.6.9 Subroutine call statements
subroutine_call_statement ::= subroutine_call ;
| void ' ( function_subroutine_call ) ;
A.6.10 Assertion statements
procedural_assertion_statement ::= concurrent_assertion_statement | immediate_assert_statement
immediate_assert_statement ::= assert ( expression ) action_block
A.6.11 Clocking block
clocking_declaration ::= [ default ] clocking [ clocking_identifier ] clocking_event ;
{ clocking_item }
endclocking [ : clocking_identifier ]
clocking_event ::= @ identifier | @ ( event_expression )
clocking_item ::= default default_skew ;
| clocking_direction list_of_clocking_decl_assign ;
| { attribute_instance } concurrent_assertion_item_declaration
default_skew ::= input clocking_skew
| output clocking_skew
| input clocking_skew output clocking_skew
clocking_direction ::= input [ clocking_skew ]
| output [ clocking_skew ]
| input [ clocking_skew ] output [ clocking_skew ]
| inout
list_of_clocking_decl_assign ::= clocking_decl_assign { , clocking_decl_assign }
clocking_decl_assign ::= signal_identifier [ = expression ]
clocking_skew ::= edge_identifier [ delay_control ] | delay_control
clocking_drive ::= clockvar_expression <= [ cycle_delay ] expression
| cycle_delay clockvar_expression <= expression
cycle_delay ::= ## integral_number
| ## identifier
| ## ( expression )
clockvar ::= hierarchical_identifier
clockvar_expression ::= clockvar select
A.6.12 Randsequence
randsequence_statement ::= randsequence ( [ production_identifier ] )
production { production }
endsequence
production ::= [ function_data_type ] production_identifier [ ( tf_port_list ) ] : rs_rule { | rs_rule } ;
rs_rule ::= rs_production_list [ := weight_specification [ rs_code_block ] ]
rs_production_list ::= rs_prod { rs_prod }
| rand join [ ( expression ) ] production_item production_item { production_item }
weight_specification ::= integral_number | ps_identifier | ( expression )
rs_code_block ::= { { data_declaration } { statement_or_null } }
rs_prod ::= production_item
| rs_code_block
| rs_if_else
| rs_repeat
| rs_case
production_item ::= production_identifier [ ( list_of_arguments ) ]
rs_if_else ::= if ( expression ) production_item [ else production_item ]
rs_repeat ::= repeat ( expression ) production_item
rs_case ::= case ( expression ) rs_case_item { rs_case_item } endcase
rs_case_item ::= expression { , expression } : production_item ;
| default [ : ] production_item ;
A.7 Specify section
A.7.1 Specify block declaration
specify_block ::= specify { specify_item } endspecify
specify_item ::= specparam_declaration
| pulsestyle_declaration
| showcancelled_declaration
| path_declaration
| system_timing_check
pulsestyle_declaration ::= pulsestyle_onevent list_of_path_outputs ;
| pulsestyle_ondetect list_of_path_outputs ;
showcancelled_declaration ::= showcancelled list_of_path_outputs ;
| noshowcancelled list_of_path_outputs ;
A.7.2 Specify path declarations
path_declaration ::= simple_path_declaration ;
| edge_sensitive_path_declaration ;
| state_dependent_path_declaration ;
simple_path_declaration ::= parallel_path_description = path_delay_value | full_path_description = path_delay_value
parallel_path_description ::= ( specify_input_terminal_descriptor [ polarity_operator ] => specify_output_terminal_descriptor )
full_path_description ::= ( list_of_path_inputs [ polarity_operator ] *> list_of_path_outputs )
list_of_path_inputs ::= specify_input_terminal_descriptor { , specify_input_terminal_descriptor }
list_of_path_outputs ::= specify_output_terminal_descriptor { , specify_output_terminal_descriptor }
A.7.3 Specify block terminals
specify_input_terminal_descriptor ::= input_identifier [ [ constant_range_expression ] ]
specify_output_terminal_descriptor ::= output_identifier [ [ constant_range_expression ] ]
input_identifier ::= input_port_identifier | inout_port_identifier | interface_identifier.port_identifier
output_identifier ::= output_port_identifier | inout_port_identifier | interface_identifier.port_identifier
A.7.4 Specify path delays
path_delay_value ::= list_of_path_delay_expressions | ( list_of_path_delay_expressions )
list_of_path_delay_expressions ::= t_path_delay_expression
| trise_path_delay_expression , tfall_path_delay_expression
| trise_path_delay_expression , tfall_path_delay_expression , tz_path_delay_expression
| t01_path_delay_expression , t10_path_delay_expression , t0z_path_delay_expression , tz1_path_delay_expression , t1z_path_delay_expression , tz0_path_delay_expression
| t01_path_delay_expression , t10_path_delay_expression , t0z_path_delay_expression ,
tz1_path_delay_expression , t1z_path_delay_expression , tz0_path_delay_expression , t0x_path_delay_expression ,
tx1_path_delay_expression , t1x_path_delay_expression , tx0_path_delay_expression , txz_path_delay_expression , tzx_path_delay_expression
t_path_delay_expression ::= path_delay_expression
trise_path_delay_expression ::= path_delay_expression
tfall_path_delay_expression ::= path_delay_expression
tz_path_delay_expression ::= path_delay_expression
t01_path_delay_expression ::= path_delay_expression
t10_path_delay_expression ::= path_delay_expression
t0z_path_delay_expression ::= path_delay_expression
tz1_path_delay_expression ::= path_delay_expression
t1z_path_delay_expression ::= path_delay_expression
tz0_path_delay_expression ::= path_delay_expression
t0x_path_delay_expression ::= path_delay_expression
tx1_path_delay_expression ::= path_delay_expression
t1x_path_delay_expression ::= path_delay_expression
tx0_path_delay_expression ::= path_delay_expression
txz_path_delay_expression ::= path_delay_expression
tzx_path_delay_expression ::= path_delay_expression
path_delay_expression ::= constant_mintypmax_expression
edge_sensitive_path_declaration ::= parallel_edge_sensitive_path_description = path_delay_value
| full_edge_sensitive_path_description = path_delay_value
parallel_edge_sensitive_path_description ::= ( [ edge_identifier ] specify_input_terminal_descriptor =>
( specify_output_terminal_descriptor [ polarity_operator ] : data_source_expression ) )
full_edge_sensitive_path_description ::= ( [ edge_identifier ] list_of_path_inputs *> ( list_of_path_outputs [ polarity_operator ] : data_source_expression ) )
data_source_expression ::= expression
edge_identifier ::= posedge | negedge
state_dependent_path_declaration ::= if ( module_path_expression ) simple_path_declaration
| if ( module_path_expression ) edge_sensitive_path_declaration
| ifnone simple_path_declaration
polarity_operator ::= + | -
A.7.5 System timing checks
A.7.5.1 System timing check commands
system_timing_check ::= $setup_timing_check
| $hold_timing_check
| $setuphold_timing_check
| $recovery_timing_check
| $removal_timing_check
| $recrem_timing_check
| $skew_timing_check
| $timeskew_timing_check
| $fullskew_timing_check
| $period_timing_check
| $width_timing_check
| $nochange_timing_check
$setup_timing_check ::= $setup ( data_event , reference_event , timing_check_limit [ , [ notifier ] ] ) ;
$hold_timing_check ::= $hold ( reference_event , data_event , timing_check_limit [ , [ notifier ] ] ) ;
$setuphold_timing_check ::= $setuphold (reference_event , data_event , timing_check_limit , timing_check_limit [ , [ notifier ] [ , [ stamptime_condition ] [ , [ checktime_condition ][ , [ delayed_reference ] [ , [ delayed_data ] ] ] ] ] ] ) ;
$recovery_timing_check ::= $recovery ( reference_event , data_event , timing_check_limit [ , [ notifier ] ] ) ;
$removal_timing_check ::= $removal ( reference_event , data_event , timing_check_limit [ , [ notifier ] ] ) ;
$recrem_timing_check ::= $recrem ( reference_event , data_event , timing_check_limit , timing_check_limit [ , [ notifier ] [ , [ stamptime_condition ] [ , [ checktime_condition ] [ , [ delayed_reference ] [ , [ delayed_data ] ] ] ] ] ] ) ;
$skew_timing_check ::= $skew ( reference_event , data_event , timing_check_limit [ , [ notifier ] ] ) ;
$timeskew_timing_check ::= $timeskew ( reference_event , data_event , timing_check_limit [ , [ notifier ] [ , [ event_based_flag ] [ , [ remain_active_flag ] ] ] ] ) ;
$fullskew_timing_check ::= $fullskew ( reference_event , data_event , timing_check_limit , timing_check_limit [ , [ notifier ] [ , [ event_based_flag ] [ , [ remain_active_flag ] ] ] ] ) ;
$period_timing_check ::= $period ( controlled_reference_event , timing_check_limit [ , [ notifier ] ] ) ;
$width_timing_check ::= $width ( controlled_reference_event , timing_check_limit , threshold [ , [ notifier ] ] ) ;
$nochange_timing_check ::= $nochange ( reference_event , data_event , start_edge_offset , end_edge_offset [ , [ notifier ] ] ) ;
A.7.5.2 System timing check command arguments
checktime_condition ::= mintypmax_expression
controlled_reference_event ::= controlled_timing_check_event
data_event ::= timing_check_event
delayed_data ::= terminal_identifier | terminal_identifier [ constant_mintypmax_expression ]
delayed_reference ::= terminal_identifier | terminal_identifier [ constant_mintypmax_expression ]
end_edge_offset ::= mintypmax_expression
event_based_flag ::= constant_expression
notifier ::= variable_identifier
reference_event ::= timing_check_event
remain_active_flag ::= constant_mintypmax_expression
stamptime_condition ::= mintypmax_expression
start_edge_offset ::= mintypmax_expression
threshold ::=constant_expression
timing_check_limit ::= expression
A.7.5.3 System timing check event definitions
timing_check_event ::= [timing_check_event_control] specify_terminal_descriptor [ &&& timing_check_condition ]
controlled_timing_check_event ::= timing_check_event_control specify_terminal_descriptor [ &&& timing_check_condition ]
timing_check_event_control ::= posedge
| negedge
| edge_control_specifier
specify_terminal_descriptor ::= specify_input_terminal_descriptor
| specify_output_terminal_descriptor
edge_control_specifier ::= edge [ edge_descriptor { , edge_descriptor } ]
edge_descriptor ::= 01 | 10 | z_or_x zero_or_one | zero_or_one z_or_x
zero_or_one ::= 0 | 1
z_or_x ::= x | X | z | Z
timing_check_condition ::= scalar_timing_check_condition
| ( scalar_timing_check_condition )
scalar_timing_check_condition ::= expression
| ~ expression
| expression == scalar_constant
| expression === scalar_constant
| expression != scalar_constant
| expression !== scalar_constant
scalar_constant ::= 1'b0 | 1'b1 | 1'B0 | 1'B1 | 'b0 | 'b1 | 'B0 | 'B1 | 1 | 0
A.8 Expressions
A.8.1 Concatenations
concatenation ::= { expression { , expression } }
constant_concatenation ::= { constant_expression { , constant_expression } }
constant_multiple_concatenation ::= { constant_expression constant_concatenation }
module_path_concatenation ::= { module_path_expression { , module_path_expression } }
module_path_multiple_concatenation ::= { constant_expression module_path_concatenation }
multiple_concatenation ::= { expression concatenation }
streaming_concatenation ::= { stream_operator [ slice_size ] stream_concatenation }
stream_operator ::= >> | <<
slice_size ::= simple_type | constant_expression
stream_concatenation ::= { stream_expression { , stream_expression } }
stream_expression ::= expression [ with [ array_range_expression ] ]
array_range_expression ::= expression
| expression : expression
| expression +: expression
| expression -: expression
empty_queue ::= { }
A.8.2 Subroutine calls
constant_function_call ::= function_subroutine_call
tf_call ::= ps_or_hierarchical_tf_identifier { attribute_instance } [ ( list_of_arguments ) ]
system_tf_call ::= system_tf_identifier [ ( list_of_arguments ) ]
| system_tf_identifier ( data_type [ , expression ] )
subroutine_call ::= tf_call
| system_tf_call
| method_call
| randomize_call
function_subroutine_call ::= subroutine_call
list_of_arguments ::= [ expression ] { , [ expression ] } { , . identifier ( [ expression ] ) }
| . identifier ( [ expression ] ) { , . identifier ( [ expression ] ) }
method_call ::= method_call_root . method_call_body
method_call_body ::= method_identifier { attribute_instance } [ ( list_of_arguments ) ]
| built_in_method_call
built_in_method_call ::= array_manipulation_call | randomize_call
array_manipulation_call ::= array_method_name { attribute_instance } [ ( list_of_arguments ) ] [ with ( expression ) ]
randomize_call ::= randomize { attribute_instance } [ ( [ variable_identifier_list | null ] ) ] [ with constraint_block ]
method_call_root ::= expression | implicit_class_handle
array_method_name ::= method_identifier | unique | and | or | xor
A.8.3 Expressions
inc_or_dec_expression ::= inc_or_dec_operator { attribute_instance } variable_lvalue
| variable_lvalue { attribute_instance } inc_or_dec_operator
conditional_expression ::= cond_predicate ? { attribute_instance } expression : expression
constant_expression ::= constant_primary
| unary_operator { attribute_instance } constant_primary
| constant_expression binary_operator { attribute_instance } constant_expression
| constant_expression ? { attribute_instance } constant_expression : constant_expression
constant_mintypmax_expression ::= constant_expression
| constant_expression : constant_expression : constant_expression
constant_param_expression ::= constant_mintypmax_expression | data_type | $
param_expression ::= mintypmax_expression | data_type
constant_range_expression ::= constant_expression | constant_part_select_range
constant_part_select_range ::= constant_range | constant_indexed_range
constant_range ::= constant_expression : constant_expression
constant_indexed_range ::= constant_expression +: constant_expression | constant_expression -: constant_expression
expression ::= primary
| unary_operator { attribute_instance } primary
| inc_or_dec_expression | ( operator_assignment )
| expression binary_operator { attribute_instance } expression
| conditional_expression
| inside_expression
| tagged_union_expression
tagged_union_expression ::= tagged member_identifier [ expression ]
inside_expression ::= expression inside { open_range_list }
value_range ::= expression | [ expression : expression ]
mintypmax_expression ::= expression | expression : expression : expression
module_path_conditional_expression ::= module_path_expression ? { attribute_instance }
module_path_expression : module_path_expression
module_path_expression ::= module_path_primary
| unary_module_path_operator { attribute_instance } module_path_primary
| module_path_expression binary_module_path_operator { attribute_instance } module_path_expression
| module_path_conditional_expression
module_path_mintypmax_expression ::= module_path_expression
| module_path_expression : module_path_expression : module_path_expression
part_select_range ::= constant_range | indexed_range
indexed_range ::= expression +: constant_expression
| expression -: constant_expression
genvar_expression ::= constant_expression
A.8.4 Primaries
constant_primary ::= primary_literal
| ps_parameter_identifier constant_select
| specparam_identifier [ constant_range_expression ]
| genvar_identifier
| [ package_scope | class_scope ] enum_identifier
| constant_concatenation
| constant_multiple_concatenation
| constant_function_call
| ( constant_mintypmax_expression )
| constant_cast
| constant_assignment_pattern_expression
| type_reference
module_path_primary ::= number
| identifier
| module_path_concatenation
| module_path_multiple_concatenation
| function_subroutine_call
| ( module_path_mintypmax_expression )
primary ::= primary_literal
| [ implicit_class_handle . | class_scope | package_scope ] hierarchical_identifier select
| empty_queue
| concatenation
| multiple_concatenation
| function_subroutine_call
| ( mintypmax_expression )
| cast
| assignment_pattern_expression
| streaming_concatenation
| sequence_method_call
| this
| $
| null
time_literal ::= unsigned_number time_unit | fixed_point_number time_unit
time_unit ::= s | ms | us | ns | ps | fs | step
implicit_class_handle ::= this | super | this . super
bit_select ::= { [ expression ] }
select ::= [ { . member_identifier bit_select } . member_identifier ] bit_select [ [ part_select_range ] ]
constant_bit_select ::= { [ constant_expression ] }
constant_select ::= [ { . member_identifier constant_bit_select } . member_identifier ] constant_bit_select [ [ constant_part_select_range ] ]
primary_literal ::= number | time_literal | unbased_unsized_literal | string_literal
constant_cast ::= casting_type ' ( constant_expression )
cast ::= casting_type ' ( expression )
A.8.5 Expression left-side values
net_lvalue ::= ps_or_hierarchical_net_identifier constant_select
| { net_lvalue { , net_lvalue } }
| [ assignment_pattern_expression_type ] assignment_pattern_net_lvalue
variable_lvalue ::= [ implicit_class_handle . | package_scope ] hierarchical_variable_identifier select
| { variable_lvalue { , variable_lvalue } }
| [ assignment_pattern_expression_type ] assignment_pattern_variable_lvalue
| streaming_concatenation
A.8.6 Operators
unary_operator ::= + | - | ! | ~ | & | ~& | | | ~| | ^ | ~^ | ^~
binary_operator ::= + | - | * | / | % | == | != | === | !== | ==? | !=? | && | || | **
| < | <= | > | >= | & | | | ^ | ^~ | ~^ | >> | << | >>> | <<<
inc_or_dec_operator ::= ++ | --
unary_module_path_operator ::= ! | ~ | & | ~& | | | ~| | ^ | ~^ | ^~
binary_module_path_operator ::= == | != | && | || | & | | | ^ | ^~ | ~^
A.8.7 Numbers
number ::= integral_number | real_number
integral_number ::= decimal_number | octal_number | binary_number | hex_number
decimal_number ::= unsigned_number | [ size ] decimal_base unsigned_number | [ size ] decimal_base x_digit { _ } | [ size ] decimal_base z_digit { _ }
binary_number ::= [ size ] binary_base binary_value
octal_number ::= [ size ] octal_base octal_value
hex_number ::= [ size ] hex_base hex_value
sign ::= + | -
size ::= non_zero_unsigned_number
non_zero_unsigned_number ::= non_zero_decimal_digit { _ | decimal_digit}
real_number ::= fixed_point_number
| unsigned_number [ . unsigned_number ] exp [ sign ] unsigned_number
fixed_point_number ::= unsigned_number . unsigned_number
exp ::= e | E
unsigned_number ::= decimal_digit { _ | decimal_digit }
binary_value ::= binary_digit { _ | binary_digit }
octal_value ::= octal_digit { _ | octal_digit }
hex_value ::= hex_digit { _ | hex_digit }
decimal_base ::= '[s|S]d | '[s|S]D
binary_base ::= '[s|S]b | '[s|S]B
octal_base ::= '[s|S]o | '[s|S]O
hex_base ::= '[s|S]h | '[s|S]H
non_zero_decimal_digit ::= 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9
decimal_digit ::= 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9
binary_digit ::= x_digit | z_digit | 0 | 1
octal_digit ::= x_digit | z_digit | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7
hex_digit ::= x_digit | z_digit | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | a | b | c | d | e | f | A | B | C | D | E | F
x_digit ::= x | X
z_digit ::= z | Z | ?
unbased_unsized_literal ::= '0 | '1 | 'z_or_x 10
A.8.8 Strings
string_literal ::= " { Any_ASCII_Characters } "
A.9 General
A.9.1 Attributes
attribute_instance ::= (* attr_spec { , attr_spec } *)
attr_spec ::= attr_name [ = constant_expression ]
attr_name ::= identifier
A.9.2 Comments
comment ::= one_line_comment | block_comment
one_line_comment ::= // comment_text \n
block_comment ::= /* comment_text */
comment_text ::= { Any_ASCII_character }
A.9.3 Identifiers
array_identifier ::= identifier
block_identifier ::= identifier
bin_identifier ::= identifier
c_identifier ::= [ a-zA-Z_ ] { [ a-zA-Z0-9_ ] }
cell_identifier ::= identifier
class_identifier ::= identifier
class_variable_identifier ::= variable_identifier
clocking_identifier ::= identifier
config_identifier ::= identifier
const_identifier ::= identifier
constraint_identifier ::= identifier
covergroup_identifier ::= identifier
covergroup_variable_identifier ::= variable_identifier
cover_point_identifier ::= identifier
dynamic_array_variable_identifier ::= variable_identifier
enum_identifier ::= identifier
escaped_identifier ::= \ {any_ASCII_character_except_white_space} white_space
formal_identifier ::= identifier
function_identifier ::= identifier
generate_block_identifier ::= identifier
genvar_identifier ::= identifier
hierarchical_block_identifier ::= hierarchical_identifier
hierarchical_dynamic_array_variable_identifier ::= hierarchical_variable_identifier
hierarchical_event_identifier ::= hierarchical_identifier
hierarchical_identifier ::= [ $root . ] { identifier constant_bit_select . } identifier
hierarchical_net_identifier ::= hierarchical_identifier
hierarchical_parameter_identifier ::= hierarchical_identifier
hierarchical_task_identifier ::= hierarchical_identifier
hierarchical_tf_identifier ::= hierarchical_identifier
hierarchical_variable_identifier ::= hierarchical_identifier
identifier ::= simple_identifier | escaped_identifier
index_variable_identifier ::= identifier
interface_identifier ::= identifier
interface_instance_identifier ::= identifier
inout_port_identifier ::= identifier
input_port_identifier ::= identifier
instance_identifier ::= identifier
library_identifier ::= identifier
member_identifier ::= identifier
method_identifier ::= identifier
modport_identifier ::= identifier
module_identifier ::= identifier
net_identifier ::= identifier
output_port_identifier ::= identifier
package_identifier ::= identifier
package_scope ::= package_identifier ::
| $unit ::
parameter_identifier ::= identifier
port_identifier ::= identifier
production_identifier ::= identifier
program_identifier ::= identifier
property_identifier ::= identifier
ps_class_identifier ::= [ package_scope ] class_identifier
ps_covergroup_identifier ::= [ package_scope ] covergroup_identifier
ps_identifier ::= [ package_scope ] identifier
ps_or_hierarchical_net_identifier ::= [ package_scope ] net_identifier | hierarchical_net_identifier
ps_or_hierarchical_tf_identifier ::= [ package_scope ] tf_identifier | hierarchical_tf_identifier
ps_parameter_identifier ::= [ package_scope ] parameter_identifier
| { generate_block_identifier [ [ constant_expression ] ] . } parameter_identifier
ps_property_identifier ::= [ package_scope ] property_identifier
ps_sequence_identifier ::= [ package_scope ] sequence_identifier
ps_type_identifier ::= [ package_scope ] type_identifier
sequence_identifier ::= identifier
signal_identifier ::= identifier
simple_identifier ::= [ a-zA-Z_ ] { [ a-zA-Z0-9_$ ] }
specparam_identifier ::= identifier
system_tf_identifier ::= $[ a-zA-Z0-9_$ ]{ [ a-zA-Z0-9_$ ] }
task_identifier ::= identifier
tf_identifier ::= identifier
terminal_identifier ::= identifier
topmodule_identifier ::= identifier
type_identifier ::= identifier
udp_identifier ::= identifier
variable_identifier ::= identifier
A.9.4 White space
white_space ::= space | tab | newline | eof