SV-grammar

module data_type;
// TODO-2: distinguish bit and logic
initial begin: bit_vs_logic
  bit v1;
  logic v2;
  wait(b_bit_vs_logic == 1); $display("bit_vs_logic process block started");
  v2 = 'bx;
  $display("logic variable v2 = %d", v2);
  v1 = v2;
  $display("bit variable v1 = %b", v1);

  v2 = 'bz;
  $display("logic variable v2 = %b", v2);
  v1 = v2;
  $display("bit variable v1 = %b", v1);
//不管z和x，bit都是0
end

// TODO-3: enum type
initial begin: enum_type
  typedef enum {IDLE, START, PROC, END} state_t;
  state_t st1, st2;
  wait(b_enum_type == 1); $display("enum_type process block started");
  st1 = IDLE;
  $display("st1 value = %0d (int)", st1);
  $display("st1 value = %s (string)", st1); // implicit conversion
  $display("st1 value = %s (string)", st1.name());

  st2 = state_t'(1);  //注意此处赋值
  $display("st1 value = %0d (int)", st2);
  $display("st1 value = %s (string)", st2.name());
end

// TODO-4: struct type
initial begin: struct_type
  typedef struct {   //要试一下packet
    bit[7:0] addr;
    bit[31:0] data;
    bit is_write;
    int id;
  } trans_t;
  trans_t t1, t2, t3;
  wait(b_struct_type == 1); $display("struct_type process block started");
  t1 = '{'h10, 'h1122_3344, 'b1, 'h1000};  //赋值
  $display("t1 data content is %p", t1);    // 结构体的输出%p,输出的是整形


  t2.addr = 'h20;
  t2.data = 'h5566_7788;
  t2.is_write = 'b0;
  t2.id = 'h2000;
  $display("t2 data content is %p", t2);

  t3 = t2;
  t3.data = 'h99AA_BBCC;
  t3.id = 'h3000;
  $display("t3 data content is %p", t3);
  $display("t2 data content is %p", t2);
end

endmodule

// TODO-1 understand how to formulate a new string
initial begin: string_format
  string s1, s2, s3, s4, s5;
  wait(b_string_format == 1);$display("string_format process block started");
  s1 = "Welcome";
  s2 = "www.rockeric.com";

  s3 = {s1, " to ", s2}; // concatenation operator '{...}'
  $display("s3 content: %s", s3);

  s4 = $sformatf("%s to %s", s1, s2); // system format function
  $display("s4 content: %s", s4);
  s5 = $psprintf("%s to %s", s1, s2); // system format function 和{}，sformatef一样的
  $display("s5 content: %s", s5);
end

// TODO-2  understand how s3 is composed with s1 and s2
initial begin: string_builtin_function
  string s1, s2, s3;
  int i1;
  wait(b_string_builtin_function == 1); $display("string_builtin_function process block started");
  s1 = "RockerIC is established in ";
  i1 = 2015;
  s2.itoa(i1); // integer converted to string “2015”
  $display("s2 = %s", s2);
  s3 = {s1.len()+s2.len(){" "}}; // 开辟空间，不开后面不能加入进来try to comment this line and check the result
  $display("s3 content: [%s]", s3);
  for(int i=0; i<s1.len()+s2.len(); i++) begin     //拼接
    s3[i] = i < s1.len() ? s1[i] : s2[i-s1.len()]; 
    //  s3[i] = i < s1.len() ? {s3,s1[i]} : {s3,s2[i-s1.len()]}; //如果不开辟空间，可以拼接
  end
  $display("s3 content: %s", s3);
end