OpenFPGA/openfpga_flow/benchmarks/iwls2005/ac97_ctrl/rtl/ac97_int.v

127 lines
4.6 KiB
Verilog

/////////////////////////////////////////////////////////////////////
//// ////
//// WISHBONE AC 97 Controller ////
//// Interrupt Logic ////
//// ////
//// ////
//// 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_int.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_int.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 02:29:18 rudi
// Initial Checkin
//
//
//
//
`include "ac97_defines.v"
module ac97_int(clk, rst,
// Register File Interface
int_set,
// FIFO Interface
cfg, status, full_empty, full, empty, re, we
);
input clk, rst;
output [2:0] int_set;
input [7:0] cfg;
input [1:0] status;
input full_empty, full, empty, re, we;
////////////////////////////////////////////////////////////////////
//
// Local Wires
//
reg [2:0] int_set;
////////////////////////////////////////////////////////////////////
//
// Interrupt Logic
//
always @(posedge clk or negedge rst)
if(!rst) int_set[0] <= #1 1'b0;
else
case(cfg[5:4]) // synopsys parallel_case full_case
// 1/4 full/empty
2'h2: int_set[0] <= #1 cfg[0] & (full_empty | (status == 2'h0));
// 1/2 full/empty
2'h1: int_set[0] <= #1 cfg[0] & (full_empty | (status[1] == 1'h0));
// 3/4 full/empty
2'h0: int_set[0] <= #1 cfg[0] & (full_empty | (status < 2'h3));
2'h3: int_set[0] <= #1 cfg[0] & full_empty;
endcase
always @(posedge clk or negedge rst)
if(!rst) int_set[1] <= #1 1'b0;
else
if(empty & re) int_set[1] <= #1 1'b1;
always @(posedge clk or negedge rst)
if(!rst) int_set[2] <= #1 1'b0;
else
if(full & we) int_set[2] <= #1 1'b1;
endmodule