uvm中寄存器模型访问方法的源代码函数

UVM中RAL相关的一些函数

0. 引言

　　在UVM支持的寄存器操作中，有get、update、mirror、write等等一些方法，在这里整理一下他们的用法。
　　寄存器模型中的寄存器值应该与DUT保持同步，但是由于DUT的值是实时更新的，所以寄存器模型并不能实时知道这种更新，在寄存器模型中专门有个值来尽可能与DUT中寄存器的值保持一致，叫镜像值（mirrorred value）。寄存器模型中还有一个值叫期望值（respected value），这个值保存我们希望写入寄存器的值。比如希望向DUT某个寄存器写入'h1，用set函数设置期望值，然后用update任务（update会比较镜像值和期望值，如果不一样，将期望值写入DUT，并更新镜像值）。、
read/write/peek/poke/set/get/update/predict/mirror/reset/get_reset/get_mirrored_value/randomize;

1.read

task uvm_reg_field::read(output uvm_status_e       status,
                         output uvm_reg_data_t     value,
                         input  uvm_path_e         path = UVM_DEFAULT_PATH,
                         input  uvm_reg_map        map = null,
                         input  uvm_sequence_base  parent = null,
                         input  int                prior = -1,
                         input  uvm_object         extension = null,
                         input  string             fname = "",
                         input  int                lineno = 0);

2.write

   extern virtual task write (output uvm_status_e       status,
                              input  uvm_reg_data_t     value,
                              input  uvm_path_e         path = UVM_DEFAULT_PATH,
                              input  uvm_reg_map        map = null,
                              input  uvm_sequence_base  parent = null,
                              input  int                prior = -1,
                              input  uvm_object         extension = null,
                              input  string             fname = "",
                              input  int                lineno = 0);

3.peek

   extern virtual task peek(output uvm_status_e      status,
                            output uvm_reg_data_t    value,
                            input  string            kind = "",
                            input  uvm_sequence_base parent = null,
                            input  uvm_object        extension = null,
                            input  string            fname = "",
                            input  int               lineno = 0);

4.poke

task uvm_reg::poke(output uvm_status_e      status,
                   input  uvm_reg_data_t    value,
                   input  string            kind = "",
                   input  uvm_sequence_base parent = null,
                   input  uvm_object        extension = null,
                   input  string            fname = "",
                   input  int               lineno = 0);

5.set

   extern virtual function void set(uvm_reg_data_t  value,
                                    string          fname = "",
                                    int             lineno = 0);

6.get

   extern virtual function uvm_reg_data_t get(string fname = "",
                                              int    lineno = 0);

7.update

   extern virtual task update(output uvm_status_e      status,
                              input  uvm_path_e        path = UVM_DEFAULT_PATH,
                              input  uvm_reg_map       map = null,
                              input  uvm_sequence_base parent = null,
                              input  int               prior = -1,
                              input  uvm_object        extension = null,
                              input  string            fname = "",
                              input  int               lineno = 0);

8.predict

   extern virtual function bit predict (uvm_reg_data_t    value,
                                        uvm_reg_byte_en_t be = -1,
                                        uvm_predict_e     kind = UVM_PREDICT_DIRECT,
                                        uvm_path_e        path = UVM_FRONTDOOR,
                                        uvm_reg_map       map = null,
                                        string            fname = "",
                                        int               lineno = 0);

9.mirror

   extern virtual task mirror(output uvm_status_e      status,
                              input  uvm_check_e       check = UVM_NO_CHECK,
                              input  uvm_path_e        path = UVM_DEFAULT_PATH,
                              input  uvm_reg_map       map = null,
                              input  uvm_sequence_base parent = null,
                              input  int               prior = -1,
                              input  uvm_object        extension = null,
                              input  string            fname = "",
                              input  int               lineno = 0);

10.reset

   // Function: reset
   //
   // Reset the desired/mirrored value for this register.
   //
   // Sets the desired and mirror value of the fields in this register
   // to the reset value for the specified reset ~kind~.
   // See <uvm_reg_field.reset()> for more details.
   //
   // Also resets the semaphore that prevents concurrent access
   // to the register.
   // This semaphore must be explicitly reset if a thread accessing
   // this register array was killed in before the access
   // was completed
   //
   extern virtual function void reset(string kind = "HARD");

11.get_reset

   // Function: get_reset
   //
   // Get the specified reset value for this register
   //
   // Return the reset value for this register
   // for the specified reset ~kind~.
   //
   extern virtual function uvm_reg_data_t
                             get_reset(string kind = "HARD");

12.get_mirrored_value

   // Function: get_mirrored_value
   //
   // Return the mirrored value of the fields in the register.
   //
   // Does not actually read the value
   // of the register in the design
   //
   // If the register contains write-only fields, the desired/mirrored
   // value for those fields are the value last written and assumed
   // to reside in the bits implementing these fields.
   // Although a physical read operation would something different
   // for these fields, the returned value is the actual content.
   //
   extern virtual function uvm_reg_data_t  get_mirrored_value(string  fname = "",
                                               int     lineno = 0);

13.randomize