uvm_reg_sequence——寄存器模型（六）

寄存器模型

uvm_reg_sequence是UVM自带所有register sequence 的基类。 该类包含model, adapter, reg_seqr(uvm_sequencer). 感觉寄存器模型是个小的UVM系统。有自己uvm_reg_item, uvm_reg_sequence，reg_seqr, uvm_reg_adapter 是用来将寄存器的transaction 和 physical bus transaction之间的转化

//------------------------------------------------------------------------------
// TITLE: Register Sequence Classes
//------------------------------------------------------------------------------
//
// This section defines the base classes used for register stimulus generation.
//------------------------------------------------------------------------------

//------------------------------------------------------------------------------
//
// CLASS: uvm_reg_sequence
//
// This class provides base functionality for both user-defined RegModel test
// sequences and "register translation sequences".
//
// - When used as a base for user-defined RegModel test sequences, this class
//   provides convenience methods for reading and writing registers and
//   memories. Users implement the body() method to interact directly with
//   the RegModel model (held in the <model> property) or indirectly via the
//   delegation methods in this class.
//
// - When used as a translation sequence, objects of this class are
//   executed directly on a bus sequencer which are used in support of a layered sequencer
//   use model, a pre-defined convert-and-execute algorithm is provided.
//
// Register operations do not require extending this class if none of the above
// services are needed. Register test sequences can be extend from the base
// <uvm_sequence #(REQ,RSP)> base class or even from outside a sequence.
//
// Note- The convenience API not yet implemented.
//------------------------------------------------------------------------------

class uvm_reg_sequence #(type BASE=uvm_sequence #(uvm_reg_item)) extends BASE;

  `uvm_object_param_utils(uvm_reg_sequence #(BASE))

  // Parameter: BASE
  //
  // Specifies the sequence type to extend from.
  //
  // When used as a translation sequence running on a bus sequencer, ~BASE~ must
  // be compatible with the sequence type expected by the bus sequencer.
  //
  // When used as a test sequence running on a particular sequencer, ~BASE~
  // must be compatible with the sequence type expected by that sequencer.
  //
  // When used as a virtual test sequence without a sequencer, ~BASE~ does
  // not need to be specified, i.e. the default specialization is adequate.
  //
  // To maximize opportunities for reuse, user-defined RegModel sequences should
  // "promote" the BASE parameter.
  //
  // | class my_reg_sequence #(type BASE=uvm_sequence #(uvm_reg_item))
  // |                               extends uvm_reg_sequence #(BASE);
  //
  // This way, the RegModel sequence can be extended from
  // user-defined base sequences.

  // Variable: model
  //
  // Block abstraction this sequence executes on, defined only when this
  // sequence is a user-defined test sequence.
  //
  uvm_reg_block model;

  // Variable: adapter
  //
  // Adapter to use for translating between abstract register transactions
  // and physical bus transactions, defined only when this sequence is a
  // translation sequence.
  //
  uvm_reg_adapter adapter;

  // Variable: reg_seqr
  //
  // Layered upstream "register" sequencer.
  //
  // Specifies the upstream sequencer between abstract register transactions
  // and physical bus transactions. Defined only when this sequence is a
  // translation sequence, and we want to "pull" from an upstream sequencer.
  //
  uvm_sequencer #(uvm_reg_item) reg_seqr;

寄存器模型的前门访问方式：

//------------------------------------------------------------------------------
// Class: uvm_reg_frontdoor
//
// Facade class for register and memory frontdoor access.
//------------------------------------------------------------------------------
//
// User-defined frontdoor access sequence
//
// Base class for user-defined access to register and memory reads and writes
// through a physical interface.
//
// By default, different registers and memories are mapped to different
// addresses in the address space and are accessed via those exclusively
// through physical addresses.
//
// The frontdoor allows access using a non-linear and/or non-mapped mechanism.
// Users can extend this class to provide the physical access to these registers.
//
virtual class uvm_reg_frontdoor extends uvm_reg_sequence #(uvm_sequence #(uvm_sequence_item));

   // Variable: rw_info
   //
   // Holds information about the register being read or written
   //
   uvm_reg_item rw_info;

   // Variable: sequencer
   //
   // Sequencer executing the operation
   //
   uvm_sequencer_base sequencer;

   // Function: new
   //
   // Constructor, new object given optional ~name~.
   //
   function new(string name="");
      super.new(name);
   endfunction

   string fname;
   int lineno;

endclass: uvm_reg_frontdoor