mmc_tri_bus.v

USBRTL电路的VHDL和Verilog代码

/********************************************************
 *    1. File name : tri_bus.v 
 *    3. Key Feature & module : This module( tri_bus ) is
 *           for tri-state  bus between  usb and smart card.
 *
 *     5. modification history
 ********************************************************/

module mmc_tri_bus (
                out_enable, 
                data_in,
                io,
                data_out
              );

  input              out_enable;
  input              data_out;

  output             data_in;
  inout              io;


  assign data_in = io;
  assign io = ( !out_enable)? data_out  : 1'bz;

endmodule