搭建环境时adapter的用法

第一种写法：

function uvm_sequence_item reg2bus(const ref uvm_reg_bus_op rw);
      bus_transaction tr;
      tr = new("tr"); 
      tr.addr = rw.addr;
      tr.bus_op = (rw.kind == UVM_READ) ? BUS_RD: BUS_WR;
      if (tr.bus_op == BUS_WR)
         tr.wr_data = rw.data; 
      return tr;
endfunction : reg2bus

function void bus2reg(uvm_sequence_item bus_item, ref uvm_reg_bus_op rw);
      bus_transaction tr;
      if(!$cast(tr, bus_item)) begin
         `uvm_fatal(tID,
          "Provided bus_item is not of the correct type. Expecting bus_transaction")
          return;
      end
      rw.kind = (tr.bus_op == BUS_RD) ? UVM_READ : UVM_WRITE;
      rw.addr = tr.addr;
      rw.byte_en = 'h3;
      rw.data = (tr.bus_op == BUS_RD) ? tr.rd_data : tr.wr_data;
      rw.status = UVM_IS_OK;
endfunction : bus2reg

第二种写法：

function uvm_sequence_item reg2bus(const ref uvm_reg_bus_op rw);
      apb_transfer t = apb_transfer::type_id::create("t");
      t.trans_kind = (rw.kind == UVM_WRITE) ? WRITE : READ;
      t.addr = rw.addr;
      t.data = rw.data;
      t.idle_cycles = 1;
      return t;
endfunction
function void bus2reg(uvm_sequence_item bus_item, ref uvm_reg_bus_op rw);
      apb_transfer t;
      if (!$cast(t, bus_item)) begin
        `uvm_fatal("CASTFAIL","Provided bus_item is not of the correct type")
        return;
      end
      rw.kind = (t.trans_kind == WRITE) ? UVM_WRITE : UVM_READ;
      rw.addr = t.addr;
      rw.data = t.data;
      rw.status = t.trans_status == OK ? UVM_IS_OK : UVM_NOT_OK;
endfunction