OpenFPGA/openfpga_flow/benchmarks/iwls2005/ac97_ctrl/rtl/ac97_soc.v

206 lines
6.2 KiB
Verilog

/////////////////////////////////////////////////////////////////////
//// ////
//// WISHBONE AC 97 Controller ////
//// Serial Output Controller ////
//// ////
//// ////
//// Author: Rudolf Usselmann ////
//// rudi@asics.ws ////
//// ////
//// ////
//// Downloaded from: http://www.opencores.org/cores/ac97_ctrl/ ////
//// ////
/////////////////////////////////////////////////////////////////////
//// ////
//// Copyright (C) 2000-2002 Rudolf Usselmann ////
//// www.asics.ws ////
//// 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_soc.v,v 1.3 2002/09/19 06:30:56 rudi Exp $
//
// $Date: 2002/09/19 06:30:56 $
// $Revision: 1.3 $
// $Author: rudi $
// $Locker: $
// $State: Exp $
//
// Change History:
// $Log: ac97_soc.v,v $
// Revision 1.3 2002/09/19 06:30:56 rudi
// Fixed a bug reported by Igor. Apparently this bug only shows up when
// the WB clock is very low (2x bit_clk). Updated Copyright header.
//
// Revision 1.2 2002/03/05 04:44:05 rudi
//
// - Fixed the order of the thrash hold bits to match the spec.
// - Many minor synthesis cleanup items ...
//
// Revision 1.1 2001/08/03 06:54:50 rudi
//
//
// - Changed to new directory structure
//
// Revision 1.1.1.1 2001/05/19 02:29:15 rudi
// Initial Checkin
//
//
//
//
`include "ac97_defines.v"
module ac97_soc(clk, wclk, rst,
ps_ce, resume, suspended,
sync, out_le, in_valid, ld, valid
);
input clk, wclk, rst;
input ps_ce;
input resume;
output suspended;
output sync;
output [5:0] out_le;
output [2:0] in_valid;
output ld;
output valid;
////////////////////////////////////////////////////////////////////
//
// Local Wires
//
reg [7:0] cnt;
reg sync_beat;
reg sync_resume;
reg [5:0] out_le;
reg ld;
reg valid;
reg [2:0] in_valid;
reg bit_clk_r;
reg bit_clk_r1;
reg bit_clk_e;
reg suspended;
wire to;
reg [5:0] to_cnt;
reg [3:0] res_cnt;
wire resume_done;
assign sync = sync_beat | sync_resume;
////////////////////////////////////////////////////////////////////
//
// Misc Logic
//
always @(posedge clk or negedge rst)
if(!rst) cnt <= #1 8'hff;
else
if(suspended) cnt <= #1 8'hff;
else cnt <= #1 cnt + 8'h1;
always @(posedge clk)
ld <= #1 (cnt == 8'h00);
always @(posedge clk)
sync_beat <= #1 (cnt == 8'h00) | ((cnt > 8'h00) & (cnt < 8'h10));
always @(posedge clk)
valid <= #1 (cnt > 8'h39);
always @(posedge clk)
out_le[0] <= #1 (cnt == 8'h11); // Slot 0 Latch Enable
always @(posedge clk)
out_le[1] <= #1 (cnt == 8'h25); // Slot 1 Latch Enable
always @(posedge clk)
out_le[2] <= #1 (cnt == 8'h39); // Slot 2 Latch Enable
always @(posedge clk)
out_le[3] <= #1 (cnt == 8'h4d); // Slot 3 Latch Enable
always @(posedge clk)
out_le[4] <= #1 (cnt == 8'h61); // Slot 4 Latch Enable
always @(posedge clk)
out_le[5] <= #1 (cnt == 8'h89); // Slot 6 Latch Enable
always @(posedge clk)
in_valid[0] <= #1 (cnt > 8'h4d); // Input Slot 3 Valid
always @(posedge clk)
in_valid[1] <= #1 (cnt > 8'h61); // Input Slot 3 Valid
always @(posedge clk)
in_valid[2] <= #1 (cnt > 8'h89); // Input Slot 3 Valid
////////////////////////////////////////////////////////////////////
//
// Suspend Detect
//
always @(posedge wclk)
bit_clk_r <= #1 clk;
always @(posedge wclk)
bit_clk_r1 <= #1 bit_clk_r;
always @(posedge wclk)
bit_clk_e <= #1 (bit_clk_r & !bit_clk_r1) | (!bit_clk_r & bit_clk_r1);
always @(posedge wclk)
suspended <= #1 to;
assign to = (to_cnt == `AC97_SUSP_DET);
always @(posedge wclk or negedge rst)
if(!rst) to_cnt <= #1 6'h0;
else
if(bit_clk_e) to_cnt <= #1 6'h0;
else
if(!to) to_cnt <= #1 to_cnt + 6'h1;
////////////////////////////////////////////////////////////////////
//
// Resume Signaling
//
always @(posedge wclk or negedge rst)
if(!rst) sync_resume <= #1 1'b0;
else
if(resume_done) sync_resume <= #1 1'b0;
else
if(suspended & resume) sync_resume <= #1 1'b1;
assign resume_done = (res_cnt == `AC97_RES_SIG);
always @(posedge wclk)
if(!sync_resume) res_cnt <= #1 4'h0;
else
if(ps_ce) res_cnt <= #1 res_cnt + 4'h1;
endmodule