/******************************************************************************/ 
/*                                                                            */ 
/* Copyright (c) 1999 Sun Microsystems, Inc. All rights reserved.             */ 
/*                                                                            */ 
/* The contents of this file are subject to the current version of the Sun    */ 
/* Community Source License, microSPARCII ("the License"). You may not use    */ 
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/* these intellectual property rights may include one or more U.S. patents,   */ 
/* foreign patents, or pending applications.                                  */ 
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/*                                                                            */ 
/******************************************************************************/ 
/***************************************************************************
****************************************************************************
***
***  Program File:  @(#)column23.v
***
****************************************************************************
****************************************************************************/

//  @(#)column23.v	1.1  4/8/92
//
// **************************************************************
//  column23 -- 24 to 2 compression for column 23.
// **************************************************************


module column23     (
		    sum,		// compressed sum
		    carry,		// compressed carry
		    cout1,		// non-ripple carry-out
		    cout2,		// ripple carry-out
		    cin1,		// non-ripple carry-in
		    cin2,		// ripple carry-in
		    x,			// multiplicand
		    y,			// multiplier
		    pass,		// pass = {0,1}
		    fbs,		// feedback sum
		    fbc			// feedback carry
		    );
	//prop CELLCLASS "MODULE"
	//prop GENERATOR "DataPath"
	//prop TERMPLACE "BIT"

    supply0 GND;
	//prop NETTYPE "GROUND"

    output sum;
	//prop TERMPLACE "BOT"
    output carry;
	//prop TERMPLACE "BOT"
    output [11:0] cout1;
	//prop TERMPLACE "LEFT"
    output [10:0] cout2;
	//prop TERMPLACE "LEFT"
    input  [11:0] cin1;
	//prop TERMPLACE "RIGHT"
    input  [10:0] cin2;
	//prop TERMPLACE "RIGHT"
    input  [27:4] x;
	//prop TERMPLACE "TOP"
    input  [23:0] y;
	//prop TERMPLACE "LEFT"
    input pass;
	//prop TERMPLACE "LEFT"
    input fbs;
	//prop TERMPLACE "BOT"
    input fbc;
	//prop TERMPLACE "BOT"

    wire  [25:0] p;		// partial products
    wire  [11:0] cin1;
    wire  [10:0] cin2;
    wire  [10:0] s;		// internal sum's
    wire  pass;
    wire  fbs;
    wire  fbc; 

    pproduct_4 pA (
	    p[3:0],
	    x[27:24],
	    y[3:0]
	    );
	    //prop TERMPLACE "POS=0"
	       
    add4 aA (
	    s[0],
	    cout2[0],
	    cout1[0],
	    p[0],
	    p[1],
	    p[2],
	    p[3],
	    cin1[0]
	    );
	    //prop TERMPLACE "POS=1"

    pproduct_4 pB (
	    p[7:4],
	    x[23:20],
	    y[7:4]
	    );
	    //prop TERMPLACE "POS=2"

    add4 aB (
	    s[1],
	    cout2[1],
	    cout1[1],
	    p[4],
	    p[5],
	    p[6],
	    p[7],
	    cin1[1]
	    );
	    //prop TERMPLACE "POS=3"

    add4 aH (
	    s[2],
	    cout2[2],
	    cout1[2],
	    s[0],
	    s[1],
	    cin2[0],
	    cin2[1],
	    cin1[2]
	    );
	    //prop TERMPLACE "POS=4"

    pproduct_4 pC (
	    p[11:8],
	    x[19:16],
	    y[11:8]
	    );
	    //prop TERMPLACE "POS=5"

    add4 aC (
	    s[3],
	    cout2[3],
	    cout1[3],
	    p[8],
	    p[9],
	    p[10],
	    p[11],
	    cin1[3]
	    );
	    //prop TERMPLACE "POS=6"

    pproduct_4 pD (
	    p[15:12],
	    x[15:12],
	    y[15:12]
	    );
	    //prop TERMPLACE "POS=7"

    add4 aD (
	    s[4],
	    cout2[4],
	    cout1[4],
	    p[12],
	    p[13],
	    p[14],
	    p[15],
	    cin1[4]
	    );
	    //prop TERMPLACE "POS=8"

    add4 aI (
	    s[5],
	    cout2[5],
	    cout1[5],
	    s[3],
	    s[4],
	    cin2[3],
	    cin2[4],
	    cin1[5]
	    );
	    //prop TERMPLACE "POS=9"
 
    add4 aK (
	    s[6],
	    cout2[6],
	    cout1[6],
	    s[2],
	    s[5],
	    cin2[2],
	    cin2[5],
	    cin1[6]
	    );
	    //prop TERMPLACE "POS=10"

    pproduct_4 pE (
	    p[19:16],
	    x[11:8],
	    y[19:16]
	    );
	    //prop TERMPLACE "POS=11"

    add4 aE (
	    s[7],
	    cout2[7],
	    cout1[7],
	    p[16],
	    p[17],
	    p[18],
	    p[19],
	    cin1[7]
	    );
	    //prop TERMPLACE "POS=12"

    pproduct_4 pF (
	    p[23:20],
	    x[7:4],
	    y[23:20]
	    );
	    //prop TERMPLACE "POS=13"

    add4 aF (
	    s[8],
	    cout2[8],
	    cout1[8],
	    p[20],
	    p[21],
	    p[22],
	    p[23],
	    cin1[8]
	    );
	    //prop TERMPLACE "POS=14"

    add4 aJ (
	    s[9],
	    cout2[9],
	    cout1[9],
	    s[7],
	    s[8],
	    cin2[7],
	    cin2[8],
	    cin1[9]
	    );
	    //prop TERMPLACE "POS=15"

    pproduct23 pL (
	    p[25:24],
	    pass,
	    fbs,
	    fbc
	    );
	    //prop TERMPLACE "POS=16"

    add4 aL (
	    s[10],
	    cout2[10],
	    cout1[10],
	    s[9],
	    p[25],
	    p[24],
	    cin2[9],
	    cin1[10]
	    );
	    //prop TERMPLACE "POS=17"

    add4 aM (
	    sum,
	    carry,
	    cout1[11],
	    s[6],
	    s[10],
	    cin2[6],
	    cin2[10],
	    cin1[11]
	    );
	    //prop TERMPLACE "POS=18"

endmodule