Subversion Repositories ac97

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

////                                                             ////

////  WISHBONE AC 97 Codec                                       ////

////  Serial Input Block                                         ////

////                                                             ////

////                                                             ////

////  Author: Rudolf Usselmann                                   ////

////          rudi@asics.ws                                      ////

////                                                             ////

////                                                             ////

////  Downloaded from: http://www.opencores.org/cores/ac97_ctrl/ ////

////                                                             ////

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

////                                                             ////

//// Copyright (C) 2000 Rudolf Usselmann                         ////

////                    rudi@asics.ws                            ////

////                                                             ////

//// 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.                                 ////

////                                                             ////

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

//  CVS Log

//

//  $Id: ac97_codec_sin.v,v 1.1 2002-02-13 08:22:32 rudi Exp $

//

//  $Date: 2002-02-13 08:22:32 $

//  $Revision: 1.1 $

//  $Author: rudi $

//  $Locker:  $

//  $State: Exp $

//

// Change History:

//               $Log: not supported by cvs2svn $

//

//

//

`include "ac97_defines.v"

module ac97_codec_sin(clk, rst,

        sync,

        slt0, slt1, slt2, slt3, slt4, slt5,

        slt6, slt7, slt8, slt9, slt10, slt11, slt12,

        sdata_in

        );

input           clk, rst;

// --------------------------------------

// Misc Signals

input           sync;

output  [15:0]   slt0;

output  [19:0]   slt1;

output  [19:0]   slt2;

output  [19:0]   slt3;

output  [19:0]   slt4;

output  [19:0]   slt5;

output  [19:0]   slt6;

output  [19:0]   slt7;

output  [19:0]   slt8;

output  [19:0]   slt9;

output  [19:0]   slt10;

output  [19:0]   slt11;

output  [19:0]   slt12;

// --------------------------------------

// AC97 Codec Interface

input           sdata_in;

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

//

// Local Wires

//

reg             sdata_in_r;

reg     [19:0]   sr;

reg     [15:0]   slt0;

reg     [19:0]   slt1;

reg     [19:0]   slt2;

reg     [19:0]   slt3;

reg     [19:0]   slt4;

reg     [19:0]   slt5;

reg     [19:0]   slt6;

reg     [19:0]   slt7;

reg     [19:0]   slt8;

reg     [19:0]   slt9;

reg     [19:0]   slt10;

reg     [19:0]   slt11;

reg     [19:0]   slt12;

wire    [12:0]   le;

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

//

// Latch Enable logic

//

// Sync Edge Detector

reg             sync_r;

wire            sync_e;

always @(posedge clk)

        sync_r <= #1 sync;

assign sync_e = sync & !sync_r;

// Frame Counter

reg     [7:0]    cnt;

always @(posedge clk)

        if(sync_e)      cnt <= #1 0;

        else            cnt <= #1 cnt + 1;

assign le[0] = (cnt == 16);

assign le[1] = (cnt == 36);

assign le[2] = (cnt == 56);

assign le[3] = (cnt == 76);

assign le[4] = (cnt == 96);

assign le[5] = (cnt == 116);

assign le[6] = (cnt == 136);

assign le[7] = (cnt == 156);

assign le[8] = (cnt == 176);

assign le[9] = (cnt == 196);

assign le[10] = (cnt == 216);

assign le[11] = (cnt == 236);

assign le[12] = (cnt == 0);

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

//

// Output registers

//

always @(posedge clk)

        if(le[0])        slt0 <= #1 sr[15:0];

always @(posedge clk)

        if(le[1])       slt1 <= #1 sr;

always @(posedge clk)

        if(le[2])       slt2 <= #1 sr;

always @(posedge clk)

        if(le[3])       slt3 <= #1 sr;

always @(posedge clk)

        if(le[4])       slt4 <= #1 sr;

always @(posedge clk)

        if(le[5])       slt5 <= #1 sr;

always @(posedge clk)

        if(le[6])       slt6 <= #1 sr;

always @(posedge clk)

        if(le[7])       slt7 <= #1 sr;

always @(posedge clk)

        if(le[8])       slt8 <= #1 sr;

always @(posedge clk)

        if(le[9])       slt9 <= #1 sr;

always @(posedge clk)

        if(le[10])      slt10 <= #1 sr;

always @(posedge clk)

        if(le[11])      slt11 <= #1 sr;

always @(posedge clk)

        if(le[12])      slt12 <= #1 sr;

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

//

// Serial Shift Register

//

always @(negedge clk)

        sdata_in_r <= #1 sdata_in;

always @(posedge clk)

        sr <= #1 {sr[18:0], sdata_in_r };

endmodule