/*
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/*
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Asynchronous SDM NoC
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Asynchronous SDM NoC
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(C)2011 Wei Song
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(C)2011 Wei Song
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Advanced Processor Technologies Group
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Advanced Processor Technologies Group
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Computer Science, the Univ. of Manchester, UK
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Computer Science, the Univ. of Manchester, UK
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Authors:
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Authors:
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Wei Song wsong83@gmail.com
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Wei Song wsong83@gmail.com
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License: LGPL 3.0 or later
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License: LGPL 3.0 or later
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M-to-1 asynchronous tree arbiter.
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M-to-1 asynchronous tree arbiter.
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History:
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History:
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03/09/2009 Initial version. <wsong83@gmail.com>
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03/09/2009 Initial version. <wsong83@gmail.com>
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23/05/2011 Clean up for opensource. <wsong83@gmail.com>
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23/05/2011 Clean up for opensource. <wsong83@gmail.com>
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*/
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*/
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module tree_arb (/*AUTOARG*/
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module tree_arb (/*AUTOARG*/
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// Outputs
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// Outputs
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gnt,
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gnt,
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// Inputs
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// Inputs
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req
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req
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) ;
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) ;
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// parameters
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// parameters
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parameter MR = 2; // the number of request inputs
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parameter MR = 2; // the number of request inputs
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localparam TrLev = mlog2(MR)-1; // the number of levels of the tree
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localparam TrLev = mlog2(MR)-1; // the number of levels of the tree
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input [MR-1:0] req; // the request input
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input [MR-1:0] req; // the request input
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output [MR-1:0] gnt; // the grant output
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output [MR-1:0] gnt; // the grant output
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// generate variables
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// generate variables
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genvar i, j, k;
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genvar i, j, k;
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// internal wires
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// internal wires
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wire [MR*2:0] mreq; // the internal request lines
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wire [MR*2:0] mreq; // the internal request lines
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wire [MR*2:0] mgnt; // the internal gnt lines
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wire [MR*2:0] mgnt; // the internal gnt lines
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wire [1:0] rgnt; // the positive gnt of the root mutex
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wire [1:0] rgnt; // the positive gnt of the root mutex
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// the hardware block
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// the hardware block
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generate
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generate
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if (MR == 1) // special case: only one input
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if (MR == 1) // special case: only one input
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begin: MA_1
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begin: MA_1
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assign gnt = req;
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assign gnt = req;
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end
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end
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else if(MR == 2) // special case: only two input
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else if(MR == 2) // special case: only two input
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begin: MA_2
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begin: MA_2
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mutex ME0 (
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mutex2 ME0 (
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.a ( req[0] ),
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.a ( req[0] ),
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.b ( req[1] ),
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.b ( req[1] ),
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.qa ( gnt[0] ),
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.qa ( gnt[0] ),
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.qb ( gnt[1] )
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.qb ( gnt[1] )
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);
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);
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end
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end
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else
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else
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begin: MA_N
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begin: MA_N
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mutex ME0 (
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mutex2 ME0 (
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.a ( mreq[0] ),
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.a ( mreq[0] ),
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.b ( mreq[1] ),
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.b ( mreq[1] ),
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.qa ( rgnt[0] ),
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.qa ( rgnt[0] ),
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.qb ( rgnt[1] )
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.qb ( rgnt[1] )
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);
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);
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assign mgnt[1:0] = ~rgnt;
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assign mgnt[1:0] = ~rgnt;
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for (i=1; 2**(i+1)<MR; i=i+1) begin: L
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for (i=1; 2**(i+1)<MR; i=i+1) begin: L
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for (j=0; j<2**i; j=j+1) begin: T
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for (j=0; j<2**i; j=j+1) begin: T
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tarb TA (
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tarb TA (
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.ngnt ( mgnt[(2**i-1)*2+j*2+1:(2**i-1)*2+j*2] ),
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.ngnt ( mgnt[(2**i-1)*2+j*2+1:(2**i-1)*2+j*2] ),
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.ntgnt ( mgnt[(2**(i-1)-1)*2+j] ),
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.ntgnt ( mgnt[(2**(i-1)-1)*2+j] ),
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.req ( mreq[(2**i-1)*2+j*2+1:(2**i-1)*2+j*2] ),
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.req ( mreq[(2**i-1)*2+j*2+1:(2**i-1)*2+j*2] ),
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.treq ( mreq[(2**(i-1)-1)*2+j] )
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.treq ( mreq[(2**(i-1)-1)*2+j] )
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);
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);
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end
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end
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end
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end
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for (j=0; j<MR-(2**TrLev); j=j+1) begin: LF
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for (j=0; j<MR-(2**TrLev); j=j+1) begin: LF
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tarb TA (
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tarb TA (
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.ngnt ( mgnt[(2**TrLev-1)*2+j*2+1:(2**TrLev-1)*2+j*2] ),
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.ngnt ( mgnt[(2**TrLev-1)*2+j*2+1:(2**TrLev-1)*2+j*2] ),
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.ntgnt ( mgnt[(2**(TrLev-1)-1)*2+j] ),
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.ntgnt ( mgnt[(2**(TrLev-1)-1)*2+j] ),
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.req ( mreq[(2**TrLev-1)*2+j*2+1:(2**TrLev-1)*2+j*2] ),
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.req ( mreq[(2**TrLev-1)*2+j*2+1:(2**TrLev-1)*2+j*2] ),
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.treq ( mreq[(2**(TrLev-1)-1)*2+j] )
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.treq ( mreq[(2**(TrLev-1)-1)*2+j] )
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);
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);
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end
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end
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assign gnt = ~(mgnt[2*MR-3:MR-2]);
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assign gnt = ~(mgnt[2*MR-3:MR-2]);
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assign mreq[2*MR-3:MR-2] = req;
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assign mreq[2*MR-3:MR-2] = req;
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end
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end
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endgenerate
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endgenerate
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// log_2 function
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// log_2 function
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function integer mlog2;
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function integer mlog2;
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input integer MR;
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input integer MR;
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begin
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begin
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for( mlog2 = 0; 2**mlog2<MR; mlog2=mlog2+1)
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for( mlog2 = 0; 2**mlog2<MR; mlog2=mlog2+1)
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begin
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begin
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end
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end
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end
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end
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endfunction // mlog2
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endfunction // mlog2
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endmodule // tree_arb
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endmodule // tree_arb
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