Section 6.3.2.1, page 67 (IEEE Std 1800™-2005)

Change

A parameter to which $ is assigned shall only be used wherever $ can be specified as a literal constant.

To

A parameter to which $ is assigned shall only be used wherever $ can be specified as a literal constant.

This includes the following situations:

- The specification of an array as a queue (Clause 5.14) in which case the parameter selects between a queue data type and a bounded array declaration.

- Upper bounds on delay and repetition ranges in assertions (Clause 17)

- Upper or lower bound on ranges in bin specifications in covergroups (Clause 18.4)

Change

To support whether a constant is $, a system function is provided to test whether a constant is a $. The syntax

of the system function is

$isunbounded(const_expression);

$isunbounded returns true if const_expression is unbounded. Typically, $isunbounded would be used as

a condition in the generate statement.

To

A system function is provided to test whether a constant is a $. The syntax of the system function is

$isunbounded(constant_param_expression);

$isunbounded is of type bit and returns the value 1 (true) if constant_param_expression is the symbol $. A parameter can be assigned $ provided that it is not involved in any expression. Such a parameter can be used only wherever the symbol $ is allowed. Typically, $isunbounded(constant_param_expression) would be used as a condition in the generate statement.

Section 6.3.2.1, page 68 (IEEE Std 1800™-2005)

Change

interface quiet_time_checker #(parameter min_quiet = 0,

parameter max_quiet = 0)

(input logic clk, reset_n, logic [1:0]en);

generate

if ( max_quiet == 0) begin

property quiet_time;

@(posedge clk) reset_n |-> ($countones(en) == 1);

endproperty

a1: assert property (quiet_time);

end

else begin

property quiet_time;

@(posedge clk)

(reset_n && ($past(en) != 0) && en == 0)

|->(en == 0)[*min_quiet:max_quiet]

##1 ($countones(en) == 1);

endproperty

a1: assert property (quiet_time);

end

if ((min_quiet == 0) && ($isunbounded(max_quiet))

$display(warning_msg);

endgenerate

endinterface

To

interface quiet_time_checker #(parameter min_quiet = 0,

parameter max_quiet = 0)

(input logic clk, logic [1:0]en);

generate

if (!$isunbounded(max_quiet) && (max_quiet == 0)) begin

property quiet_time;

@(posedge clk) ($countones(en) == 1);

endproperty

a1: assert property (quiet_time);

end

else begin

property quiet_time;

@(posedge clk)

(reset_n && ($past(en) != 0) && en == 0)

|->(en == 0)[*min_quiet:max_quiet]

##1 ($countones(en) == 1);

endproperty

a1: assert property (quiet_time);

initial if ((min_quiet == 0) && ($isunbounded(max_quiet))

$display(warning_msg);

endgenerate

endinterface

Section Index, page 637 (IEEE Std 1800™-2005)

Change

$isunbounded 380

To

$isunbounded 67, 380

Section 22.4, page 380 (IEEE Std 1800™-2005)

Change

range_function ::= // not in Annex A

$isunbounded ( constant_expression )

To

range_function ::= // not in Annex A

$isunbounded ( constant_param_expression )

Change

then $isunbounded(foo) shall return true. Otherwise, it shall return false. True and false are defined in

22.9.

to

then $isunbounded(foo) shall return true. Otherwise, it shall return false. True and false are defined in

22.9. If a parameter is assigned $ then it must not be involved in any expression.

Such a parameter can be used only wherever the symbol $ is allowed. Additional description and examples can be found in 6.3.2.1.