H ierarchical references to imported identifiers are

• h ierarchical references to imported identifiers are allowed as if they are defined in the
importing scope
• E xplicit import like a local declaration
• m ultiple identical allowed
module my_design ();
my_global_stuff_pkg::traffic_stop_t my_traffic_stop;
module my_design ();
import my_global_stuff_pkg::*;
Advanced Hardware Design & Verification
SystemVerilog

package ComplexPkg;
typedef struct {
float i, r;
} Complex;
Complex C_data = ‘{i:2.0, r:5.7};
function Complex ADD (Complex a, b)
ADD.r = a.r + b.r;
ADD.i = a.i + b.i;
endfunction : ADD
function Complex MULT (Complex a, b)
MULT.r = (a.r * b.r) + (a.i * b.i);
MULT.i = (a.r * b.i) + (a.i * b.r);
endfunction : MULT
endpackage : ComplexPkg
[ Verification] Data - Types
package s
Importing - Examples
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ComplexPkg::C_data =
ComplexPkg::MULT(a, b);
import ComplexPkg::C_data;
initial C_data = ‘{i:6.0,r:2.7};
import ComplexPkg::*;
initial C_data = ADD(a, b);
Advanced Hardware Design & Verification
SystemVerilog

[ Verification] Data - Types
( classes_pkg.sv ) for a De - Bouncer
Complete Example
package classes_pkg;
class PushButton;
// Class Properties
rand bit [31:0] delay;
constraint c_delay {delay > 20; // Delay is > than 20 ns
delay < 7000000;} // Delay is < 7 ms
function new ( );
delay = 0;
endfunction
endclass : PushButton
endpackage : classes_pkg
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module key_bfm (clk, reset, key);
output key;
input reset, clk;
// Import Classes
import classes_pkg::*;
// Define local Variables
reg key;
PushButton key_obj;
task push_button( );
time delay;
begin
key_obj.randomize ( );
delay = key_obj.delay;
key = 1'b1;
# delay key = 1'b0;
end
endtask
initial
begin
key = 1'b0;
key_obj = new ( );
end
endmodule : key_bfm
Advanced Hardware Design & Verification
SystemVerilog

[ Verification] Data - Types
User - Defined Structures
struct
typedef
struct {
int hw_grade_1;
int hw_grade_2;
int hw_grade_1;
int hw_grade_2;
int hw_grade_5;
} hw_grades_s;
S uppose you want to group variables into a block or a structure. you can do so by using
a struct keyword. It’s functionality is similar to that of other programming languages.
Structure and union declarations follow the C syntax, but without the optional structure
tags before the ‘{‘.
I t is recommended that you start appending your new
variables with their associated type. For example, we
use the postfix “ _s ” to indicate a structure data type.
struct {
bit [7:0] opcode;
bit [23:0] addr;
} IR; // anonymous structure
// defines variable IR
IR.opcode = 1; // set field in IR.
W e can define struts' that are
user-defined data-types.
W e can create a variable structure.
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Advanced Hardware Design & Verification
SystemVerilog

[ Verification] Data - Types
Constants
Example Code and explanation
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initial begin
const byte colon = “:”;
...
end
Pages: 61
A const form of constant differs from a
localparam constant in that the localparam
must be set during elaboration, whereas a
const can be set during simulation, such
as in an automatic task. [SVLRM]
initial begin
...