register.v

精简CPU设计

module register(opc_iraddr,data,ena,clk1,rst);
    output[15:0] opc_iraddr;
    input[7:0] data;
    input ena,clk1,rst;
    reg[15:0] opc_iraddr;
    reg state;
    
    always @(posedge clk1)
       begin
           if(!rst)
             begin
                 opc_iraddr<=16'h0000;
                 state<=1'b0;
             end
           else
             begin
                if(ena)
                  begin
                      case(state)
                          1'b0: begin
                                  opc_iraddr[15:8]<=data;
                                  state<=1'b1;
                                end
                          1'b1: begin
                                   opc_iraddr[7:0]<=data;
                                   state<=1'b0;
                                end
                       default: begin
                                   opc_iraddr<=16'hxxxx;
                                   state<=1'bx;
                                end
                      endcase
                  end
                else
                  state<=1'b0;
               end
           end
endmodule