src/uncore/axi4/Semi_FIFOF.bsv

   1 /*
   2 Copyright (c) 2013, IIT Madras
   3 All rights reserved.
   4
   5 Redistribution and use in source and binary forms, with or without
   6 modification, are permitted provided that the following conditions
   7 are met:
   8
   9 *  Redistributions of source code must retain the above copyright notice,
  10    this list of conditions and the following disclaimer.
  11 *  Redistributions in binary form must reproduce the above copyright
  12    notice, this list of conditions and the following disclaimer in the
  13    documentation and/or other materials provided with the distribution.
  14 *  Neither the name of IIT Madras  nor the names of its contributors
  15    may be used to endorse or promote products derived from this software
  16    without specific prior written permission.
  17
  18 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  20 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  21 A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  22 HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  23 SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
  24 TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  25 PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  26 LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  27 NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  28 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29 -----------------------------------------------------------------------
  30
  31 */
  32 // Copyright (c) 2017 Bluespec, Inc.  All Rights Reserved
  33
  34 package Semi_FIFOF;
  35
  36 // ================================================================
  37 // Separate interfaces for input-side and output-side of FIFOF.
  38 // Conversion functions to these, from FIFOF interfaces.
  39
  40 // ================================================================
  41 // BSV library imports
  42
  43 import FIFOF       :: *;
  44 import Connectable :: *;
  45
  46 // ================================================================
  47 // Semi-FIFOF interfaces
  48
  49 interface FIFOF_I #(type t);
  50    method Action  enq (t x);
  51    method Bool    notFull ();
  52 endinterface
  53
  54 interface FIFOF_O #(type t);
  55    method t       first ();
  56    method Action  deq ();
  57    method Bool    notEmpty ();
  58 endinterface
  59
  60 // ================================================================
  61 // Converters from FIFOF
  62
  63 function FIFOF_I #(t) to_FIFOF_I (FIFOF #(t) f);
  64    return interface FIFOF_I;
  65              method enq (x) = f.enq (x);
  66              method notFull = f.notFull;
  67           endinterface;
  68 endfunction
  69
  70 function FIFOF_O #(t) to_FIFOF_O (FIFOF #(t) f);
  71    return interface FIFOF_O;
  72              method first    = f.first;
  73              method deq      = f.deq;
  74              method notEmpty = f.notEmpty;
  75           endinterface;
  76 endfunction
  77
  78 // ================================================================
  79 // Connections
  80
  81 // ----------------
  82 // FIFOF_O to a FIFOF_I
  83
  84 instance Connectable #(FIFOF_O #(t), FIFOF_I #(t));
  85    module mkConnection #(FIFOF_O #(t) fo, FIFOF_I #(t) fi) (Empty);
  86       rule rl_connect;
  87          fi.enq (fo.first);
  88          fo.deq;
  89       endrule
  90    endmodule
  91 endinstance
  92
  93 // ----------------
  94 // FIFOF_O to a FIFOF
  95
  96 instance Connectable #(FIFOF_O #(t), FIFOF #(t));
  97    module mkConnection #(FIFOF_O #(t) fo, FIFOF #(t) fi) (Empty);
  98       rule rl_connect;
  99          fi.enq (fo.first);
 100          fo.deq;
 101       endrule
 102    endmodule
 103 endinstance
 104
 105 // ----------------
 106 // FIFOF to a FIFOF_I
 107
 108 instance Connectable #(FIFOF #(t), FIFOF_I #(t));
 109    module mkConnection #(FIFOF #(t) fo, FIFOF_I #(t) fi) (Empty);
 110       rule rl_connect;
 111          fi.enq (fo.first);
 112          fo.deq;
 113       endrule
 114    endmodule
 115 endinstance
 116
 117 // ================================================================
 118 // Convenience function combining first/enq
 119
 120 function ActionValue #(t) pop_o (FIFOF_O #(t) f);
 121    actionvalue
 122       f.deq;
 123       return f.first;
 124    endactionvalue
 125 endfunction
 126
 127 // ================================================================
 128
 129 endpackage