register.v

8位RISC CPU,包括alu,count,machine等等

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'b0000000000000000;
      state<=1'b0;
    end
  else
    begin
      if(ena)
        begin
         casex(state)
            1'b0: begin
                    opc_iraddr[15:8]<=data;
                    state<=1;
                  end
            1'b1: begin
                    opc_iraddr[7:0]<=data;
                    state<=0;
                  end
            default:begin
                    opc_iraddr[15:0]<=16'bxxxxxxxxxxxxxxxx;
                    state<=1'bx;
                    end
         endcase
        end
       else
            state<=1'b0;
     end
  end
endmodule