vsr_4_3_tx_binary_search.v

甚短距离互联（Veryshort reach VSR）协议编成实现

/////////////////////////////////////////////////////////////////////
////                                                             ////
////  vsr_4_03	binary search for the a1a2 boundary		 ////
////                                                             ////
////  Author: liyu	                                         ////
////          [e-mail]                              ////
////          		                                         ////
////                                                             ////
/////////////////////////////////////////////////////////////////////
////                                                             ////
//// Copyright (C) 2004 liyu                        		 ////
////                    [e-mail]                    ////
////                                                             ////
//// This source file may be used and distributed without        ////
//// restriction provided that this copyright statement is not   ////
//// removed from the file and that any derivative work contains ////
//// the original copyright notice and the associated disclaimer.////
////                                                             ////
////     THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY     ////
//// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED   ////
//// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS   ////
//// FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL THE AUTHOR      ////
//// OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,         ////
//// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES    ////
//// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE   ////
//// GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR        ////
//// BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF  ////
//// LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT  ////
//// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT  ////
//// OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE         ////
//// POSSIBILITY OF SUCH DAMAGE.                                 ////
////                                                             ////
/////////////////////////////////////////////////////////////////////

//synopsys translate_off
`include "timescale.v"
//synopsys translate_on

module vsr_4_3_tx_binary_search(din,sel,clk,rst);
input	[62:0]	din;
output	[5:0]	sel;
input		clk;
input		rst;

reg	[30:0]	da;
reg	[14:0]	db;
reg	[6:0]	dc;
reg	[2:0]	dd;
reg		de;


always@(posedge clk or posedge rst)
begin
	if (rst) begin
		da<=30'b0;
		db<=15'b0;
		dc<=7'b0;
		dd<=3'b0;
		de<=1'b0;
	end	
	else begin
		da<=(din[32:31])?din[62:32] :din[30:0];
		db<=( da[16:15])? da[30:16] : da[14:0];
		dc<=( db[8:7]  )? db[14:8]  : db[6:0] ;
		dd<=( dc[4:3]  )? dc[6:4]   : dc[2:0] ;
		de<=( dd[2:1]  )? dd[2]     : dd[0]   ;
	end	
end

wire	[5:0]	control;
assign		control[5]=(din[32:31])?1'b1:1'b0;
assign		control[4]=( da[16:15])?1'b1:1'b0;
assign		control[3]=( db[8:7]  )?1'b1:1'b0;
assign		control[2]=( dc[4:3]  )?1'b1:1'b0;
assign		control[1]=( dd[2:1]  )?1'b1:1'b0;
assign		control[0]=de;

reg	[5:0]	sel;
always@(posedge clk or posedge rst)
begin
	if (rst) begin
		sel<=6'b000000;
	end
	else begin
		sel<=control;
	end
end	

endmodule