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////  WISHBONE AC 97 Controller Definitions                      ////

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

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

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

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//// Copyright (C) 2001 Rudolf Usselmann                         ////

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

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//// 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_defines.v,v 1.4 2002-03-11 03:21:22 rudi Exp $

//

//  $Date: 2002-03-11 03:21:22 $

//  $Revision: 1.4 $

//  $Author: rudi $

//  $Locker:  $

//  $State: Exp $

//

// Change History:

//               $Log: not supported by cvs2svn $

//               Revision 1.3  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 1.2  2001/08/10 08:09:42  rudi

//

//               - Removed RTY_O output.

//               - Added Clock and Reset Inputs to documentation.

//               - Changed IO names to be more clear.

//               - Uniquifyed define names to be core specific.

//

//               Revision 1.1  2001/08/03 06:54:49  rudi

//

//

//               - Changed to new directory structure

//

//               Revision 1.1.1.1  2001/05/19 02:29:14  rudi

//               Initial Checkin

//

//

//

//

`timescale 1ns / 10ps

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

// This AC97 Controller supports up to 6 Output and 3 Input Channels.

// Comment out the define statement for which channels you do not wish

// to support in your implementation. The main Left and Right channels

// are always supported. 

// Surround Left + Right

`define AC97_SURROUND           1

// Center Channel

`define AC97_CENTER             1

// LFE Channel

`define AC97_LFE                1

// Stereo Input

`define AC97_SIN                1

// Mono Microphone Input

`define AC97_MICIN              1

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

//

// This define selects how the WISHBONE interface determines if

// the internal register file is selected.

// This should be a simple address decoder. "wb_addr_i" is the

// WISHBONE address bus (32 bits wide).

`define AC97_REG_SEL            (wb_addr_i[31:29] == 3'h0)

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

//

// This is a prescaler that generates a pulse every 250 nS.

// The value here should one less than the actually calculated

// value.

// For a 200 MHz wishbone clock, this value is 49 (50-1).

`define AC97_250_PS     6'h31

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

//

// AC97 Cold reset Must be asserted for at least 1uS. The AC97

// controller will stretch the reset pulse to at least 1uS.

// The reset timer is driven by the AC97_250_PS prescaler.

// This value should probably be never changed. Adjust the

// AC97_250_PS instead.

`define AC97_RST_DEL    3'h4

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

//

// This value indicates for how long the resume signaling (asserting sync)

// should be done. This counter is driven by the AC97_250_PS prescaler.

// This value times 250nS is the duration of the resume signaling.

// The actual value must be incremented by one, as we do not know

// the current state of the prescaler, and must somehow insure we

// meet the minimum 1uS length. This value should probably be never

// changed. Modify the AC97_250_PS instead.

`define AC97_RES_SIG    3'h5

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

//

// If the bit clock is absent for at least two "predicted" bit

// clock periods (163 nS) we should signal "suspended".

// This value defines how many WISHBONE cycles must pass without

// any change on the bit clock input before we signal "suspended".

// For a 200 MHz WISHBONE clock this would be about (163/5) 33 cycles.

`define AC97_SUSP_DET   6'h21

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

//

// Select FIFO Depth. For most applications a FIFO depth of 4 should

// be sufficient. For systems with slow interrupt processing or slow

// DMA response or systems with low internal bus bandwidth you might

// want to increase the FIFO sizes to reduce the interrupt/DMA service

// request frequencies.

// Service request frequency can be calculated as follows:

// Channel bandwidth / FIFO size = Service Request Frequency

// For Example: 48KHz / 4 = 12 kHz

//

// Select Input FIFO depth by uncommenting ONE of the following define

// statements:

`define AC97_IN_FIFO_DEPTH_4

//`define AC97_IN_FIFO_DEPTH_8

//`define AC97_IN_FIFO_DEPTH_16

//

// Select Output FIFO depth by uncommenting ONE of the following define

// statements:

`define AC97_OUT_FIFO_DEPTH_4

//`define AC97_OUT_FIFO_DEPTH_8

//`define AC97_OUT_FIFO_DEPTH_16