added simul fifo to sensor/sensor_i2c.v

        .rvalid          (i2c_rvalid)       // output

    );

`ifdef SENSOR_SPI    

    simul_fifo

    #(

      .WIDTH(32),

      .DEPTH(64)

    )simmul_fifo_i(

         .clk(mclk),

         .reset(mrst),

         .data_in(di_r),

         .load(i2c_cmd_we),

         .input_ready(),

         .data_out(data_spi),

         .valid(valid_spi),

         .ready(read_spi));

`else

    ram_var_w_var_r #(

        .REGISTERS(1), // try to delay i2c_byte_start by one more cycle

        .data_in  (di_r) // input[31:0] 

    );

`endif    

endmodule