SystemVerilog Assertion 设计、调试、测试总结（3）

上两篇主要是讲述断言的概念，基本语法，总结等等
这一篇主要是以PPT的形式展示各个场景下关于断言的应用。
为了在设计中加入断言的功能，因此需要写一个DUT。如下：
`define true 1
`define free (a && b && c && d)

module assertion(
  input clk,
  input rst_n
);

  reg   a     = 1'b0  ;
  reg   b     = 1'b0  ;
  reg   c     = 1'b0  ;
  reg   d     = 1'b0  ;
  reg   e     = 1'b0  ;
  reg   f     = 1'b0  ;
  reg   start = 1'b0  ;
  reg   stop  = 1'b0  ;
  
  always @(posedge clk)
  begin
    a     <= $urandom_range(0,1);
    b     <= $urandom_range(0,1);
    c     <= $urandom_range(0,1);
    d     <= $urandom_range(0,1);
    e     <= $urandom_range(0,1);
    f     <= $urandom_range(0,1);
    start <= $urandom_range(0,1);
    stop  <= $urandom_range(0,1);
  end
  
  assign state = {a,b,c,d};
  assign bus   = {a,b,c,d};
    
`ifdef SIM_ASSERTION_ON
//a1
  sequence s1;
    @(posedge clk) a;
  endsequence
  
  property p1;
    s1;
  endproperty

  a1: assert property (p1);
  
//a2
  sequence s2;
    @(posedge clk) $rose(a);
  endsequence
  
  property p2;
    s2;
  endproperty
  
  a2: assert property (p2);

//a3
  property p3;
    @(posedge clk) a || b;
  endproperty

  a3: assert property (p3);
  
//a4
  sequence s4;
    @(posedge clk) a ##2 b;
  endsequence
  
  property p4;
    s4;
  endproperty

  a4: assert property (p4);
  
//a5
  property p5;
    @(posedge clk) a ##2 b;
  endproperty

  a5:assert property(p5);
  
//a6
  sequence s6;
    @(posedge clk) a ##2 b;
  endsequence

  property p6;
    not s6;
  endproperty

  a6: assert property(p6);

//a7
  property p7;
    @(posedge clk) a ##2 b;
  endproperty

  a7: assert property (p7)
    $display("Property p7 successed\n");
    else
    $display("Property p7 failed\n");

//a8
  property p8;
    @(posedge clk) a |-> b;
  endproperty

  a8: assert property (p8);

//a9
  property p9;
    @(posedge clk) a |=> b;
  endproperty

  a9: assert property (p9);

//a10
  property p10;
    @(posedge clk) a |-> ##2 b;
  endproperty

  a10: assert property (p10);
  
//a11
  sequence s11a;
    @(posedge clk)(a && b) ##1 c;
  endsequence

  sequence s11b;
    @(posedge clk)  ##2 !d;
  endsequence

  property p11;
    s11a |-> s11b;
  endproperty

  a11: assert property (p11);

//a12
  property p12;
    @(posedge clk) ( a&&b ) |-> ## [1:3] c;
  endproperty 

  a12: assert property (p12);
  
//a13
  property p13;
    @(posedge clk) ( a&&b ) |-> ## [0:2] c;
  endproperty

  a13: assert property (p13);

//a14
  property p14;
    @(posedge clk) a |-> ##[1:$] b ##[0:$] c;
  endproperty

  a14: assert property (p14);


//a15
  sequence s15a;
    @(posedge clk) a ##1 b;
  endsequence

  sequence s15b;
    @(posedge clk) c ##1 d;
  endsequence

  property p15a;
    s15a |=> s15b;
  endproperty

  property p15b;
    s15a.ended |-> ##2 s15b.ended;
  endproperty 
     
  a15a: assert property (p15a);
  a15b: assert property (p15b); 
    

//a17
  property p17;
    @(posedge clk) c ? d == a : d == b;
  endproperty
  
 a17: assert property(p17);

//a18
  sequence s18a;
    @(posedge clk) a ##1 b;
  endsequence

  sequence s18a_ext;
    @(posedge clk) a ##1 b ##1 `true;
  endsequence

  sequence s18b;
    @(posedge clk) c ##1 d;
  endsequence
  
  property p18;
    @(posedge clk) s18a.ended |-> ##2 s18b.ended;
  endproperty
  
  property p18_ext;
    @(posedge clk) s18a_ext.ended |-> ##2 s18b.ended;
  endproperty

  a18: assert property (p18);
  a18_ext: assert property (p18_ext);

//a19
  property p19;
    @(posedge clk) (c && d) |-> ($past((a&&b), 2) == 1'b1);
  endproperty

  a19: assert property (p19);

//a20
  property p20;
    @(posedge clk) (c && d) |-> ($past ( ( a&&b ), 2, e) == 1'b1);
  endproperty

  a20: assert property (p20);

//a21
  property p21;
    @(posedge clk) $rose(start) |-> ##2 (a[*3]) ##2 stop ##1 !stop ;
  endproperty

  a21: assert property (p21);

//a22
  property p22;
    @(posedge clk) $rose(start) |-> ##2 ((a ##2 b) [*3]) ##2 stop ;
  endproperty
  
  a22: assert property (p22);

//a23
  property p23;
    @(posedge clk) $rose(start) |-> ##2 ((a ##[1:4] b) [*3]) ##2 stop ;
  endproperty
  a23: assert property (p23);

//a24
  property p24;
    @(posedge clk) $rose(start) |-> ##2 (a [*1 : $]) ##1 stop ;
  endproperty
  
  a24: assert property (p24);

//a25
  property p25;
    @(posedge clk) $rose(start) |-> ##2 (a [->3]) ##1 stop ;
  endproperty
  
  a25: assert property (p25);

//a26
  property p26;
    @(posedge clk) $rose(start) |-> ##2 (a [=3]) ##1 stop ##1 !stop;
  endproperty
  
  a26: assert property (p26);
  
//a27
  sequence s27a;
    @(posedge clk) a ##[1:2] b;
  endsequence

  sequence s27b;
    @(posedge clk) c ##[2:3] d;
  endsequence
  
  property p27;
    @(posedge clk) s27a and s27b ;
  endproperty

  a27: assert property(p27);
 
//a28
  sequence s28a;
    @(posedge clk) a ##[1:2] b;
  endsequence

  sequence s28b;
    @(posedge clk) c ##[2:3] d;
  endsequence
  
  property p28;
    @(posedge clk) s28a intersect s28b ;
  endproperty

  a28: assert property(p28);

//a29
  sequence s29a;
    @(posedge clk) a ##[1:2] b;
  endsequence

  sequence s29b;
    @(posedge clk) c ##[2:3] d;
  endsequence
  
  property p29;
    @(posedge clk) s29a or s29b ;
  endproperty

  a29: assert property(p29);

//a30
  sequence s30a;
    @(posedge clk) a ##[1:3] b;
  endsequence

  sequence s30b;
    @(posedge clk) c ##[2:3] d;
  endsequence
  
  property p30;
    @(posedge clk) first_match (s30a or s30b) ;
  endproperty

  a30: assert property(p30);

//a31
  property p31;
    @(posedge clk) $fell(start) |-> 
                   (!start) throughout 
                   (##1 ( !a && !b ) ##1 ( c[->3] ) ##1 ( a&&b ) );
  endproperty

  a31: assert property(p31);
  
//a32
  sequence s32a;
    @(posedge clk) 
      (( !a && !b ) ##1 ( c[->3] ) ##1 ( a&&b ) );
  endsequence

  sequence s32b;
    @(posedge clk) 
      $fell(start) ## [5:10] $rose(start);
  endsequence
  
  sequence s32;
    @(posedge clk) 
      s32a within s32b;
  endsequence

  property p32;
    @(posedge clk) 
      $fell(start) |-> s32;
  endproperty

  a32: assert property(p32);

//a33
  a33a: assert property( @ (posedge clk) $onehot(state) );
  
  a33b: assert property( @ (posedge clk) $onehot0(state) );
  
  a33c: assert property( @ (posedge clk) $isunknown(bus) );
  
  a33d: assert property( @ (posedge clk) $countones (bus) );

//a34
  property p34;
    @(posedge clk) 
        disable iff (rst_n)
        $rose (start) |-> a[=2] ##1 b[=2] ##1 !start ;
  endproperty
 
//a35
  property p35;
    (@(posedge clk) 1[*2:5] intersect(a ##[1:$] b ##[1:$] c));
  endproperty

  a35: assert property(p35);
  
 
//a36
  property arb (a,b,c,d);
    @(posedge clk) ($fell (a) ##[2:5] $fell(b) ) |->
                   ##1 ($fell (c) && $fell(d) ) ## 0
                       (!c && !d) [*4] ##1 (c&&d) ##1 b;
  endproperty

  a36_1: assert property(arb(a1,b1,c1,d1));
  a36_2: assert property(arb(a2,b2,c2,d2));
  a36_3: assert property(arb(a3,b3,c3,d3));

  
//a37        
  property p_nest;
    @(posedge clk) $fell (a) |->
                   ##1 (!b && !c && !d ) |->
                   ## [6:10] `free;
  endproperty 
  
  a_nest: assert property(p_nest);
  
  property p_nest1;
    @(posedge clk) $fell (a) ##1 (!b && !c && !d )
                   |-> ## [6:10] `free;
  endproperty
  
  a_nest1: assert property(p_nest1);

//a_if_else 
  property p_if_else;
    @(posedge clk) ($fell (start)##1(a || b))|->
        if (a)
        (c[->2] ##1 e)
        else
        (d[->2] ##1 f);
  endproperty 
  
  a_if_else: assert property(p_if_else);

`endif 

endmodule