Subversion Repositories i2c_master_slave_core

////////////////////////////Shift.v/////////////////////////////////////////////////////////////////////

//                                                                                                    //        

//Design Engineer:      Ravi Gupta                                                                    //

//Company Name   :      Toomuch Semiconductor

//Email          :      ravi1.gupta@toomuchsemi.com                                                   //        

//                                                                                                    //

//Purpose        :      Used for shifting address and data in both transmit and recieve mode          //        

//created        :      22-11-07                                                                      //

//                                                                                                    //                                

////////////////////////////////////////////////////////////////////////////////////////////////////////

/*// synopsys translate_off

`include "oc8051_timescale.v"

// synopsys translate_on

`include "oc8051_defines.v"*/

module shift(clk,asyn_rst,load,shift_en,serial_in,data_in,serial_out,data_out);

input   clk,asyn_rst,load,shift_en,serial_in;

input   [7:0]data_in;

output  serial_out;

output  [7:0]data_out;

reg     [7:0]data;

always@(posedge clk or posedge asyn_rst or posedge load)

begin

        if(asyn_rst)

                data<=8'h0;                             //clear the data register upon asynchronous reset.

        else if(load)

                data<=data_in;                          //Load the internal register upon insertion of load bit.

        else if(shift_en)

                data<={data[6:0],serial_in};             //Upon shift_en high every time a new serial data is coming to LSB bit and data will be shifted

                                                        //to one bit.

        else

                data<=data;                             //Prevent formation of latches

end

assign data_out = data;                                 //Output the data in a data_register

assign serial_out = data[7];                            //MSB is transmitted first in I2C protocol.

endmodule

//change loading into asynchronous mode