view modules/bluespec/Pygar/lab4/MemArb.bsv @ 16:7e1510b47336 pygar svn.17

[svn r17] added rest of items for core
author punk
date Tue, 27 Apr 2010 22:54:50 -0400
parents 74716e9a81cc
children 3958de09a7c1
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line source
1 // The MIT License
3 // Copyright (c) 2009 Massachusetts Institute of Technology
5 // Permission is hereby granted, free of charge, to any person obtaining a copy
6 // of this software and associated documentation files (the "Software"), to deal
7 // in the Software without restriction, including without limitation the rights
8 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
9 // copies of the Software, and to permit persons to whom the Software is
10 // furnished to do so, subject to the following conditions:
12 // The above copyright notice and this permission notice shall be included in
13 // all copies or substantial portions of the Software.
15 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
21 // THE SOFTWARE.
23 import Connectable::*;
24 import GetPut::*;
25 import ClientServer::*;
26 import FIFOF::*;
27 import FIFO::*;
29 // Local includes
30 `include "asim/provides/processor_library.bsh"
32 interface MemArb;
34 interface Server#(MainMemReq,MainMemResp) cache0_server;
35 interface Server#(MainMemReq,MainMemResp) cache1_server;
36 interface Client#(MainMemReq,MainMemResp) mmem_client;
38 endinterface
40 typedef enum { REQ0, REQ1 } ReqPtr deriving(Eq,Bits);
42 module mkMemArb( MemArb );
44 //-----------------------------------------------------------
45 // State
47 FIFOF#(MainMemReq) req0Q <- mkBFIFOF1();
48 FIFO#(MainMemResp) resp0Q <- mkBFIFO1();
50 FIFOF#(MainMemReq) req1Q <- mkBFIFOF1();
51 FIFO#(MainMemResp) resp1Q <- mkBFIFO1();
53 FIFO#(MainMemReq) mreqQ <- mkBFIFO1();
54 FIFO#(MainMemResp) mrespQ <- mkBFIFO1();
56 Reg#(ReqPtr) nextReq <- mkReg(REQ0);
58 //-----------------------------------------------------------
59 // Some wires
61 let req0avail = req0Q.notEmpty();
62 let req1avail = req1Q.notEmpty();
64 //-----------------------------------------------------------
65 // Rules
67 rule chooseReq0 ( req0avail && (!req1avail || (nextReq == REQ0)) );
68 traceTiny("mkMemArb", "memArb req0",req0Q.first());
70 // Rewrite tag field if this is a load ...
71 MainMemReq mreq
72 = case ( req0Q.first() ) matches
73 tagged LoadReq .ld : return LoadReq { tag:0, addr:ld.addr };
74 tagged StoreReq .st : return req0Q.first();
75 endcase;
77 // Send out the request
78 mreqQ.enq(mreq);
79 nextReq <= REQ1;
80 req0Q.deq();
82 endrule
84 rule chooseReq1 ( req1avail && (!req0avail || (nextReq == REQ1)) );
85 traceTiny("mkMemArb", "memArb req1",req1Q.first);
87 // Rewrite tag field if this is a load ...
88 MainMemReq mreq
89 = case ( req1Q.first() ) matches
90 tagged LoadReq .ld : return LoadReq { tag:1, addr:ld.addr };
91 tagged StoreReq .st : return req1Q.first();
92 endcase;
94 // Send out the request
95 mreqQ.enq(mreq);
96 nextReq <= REQ0;
97 req1Q.deq();
99 endrule
101 rule returnResp;
102 traceTiny("mkMemArb", "resp",mrespQ.first());
104 // Use tag to figure out where to send response
105 mrespQ.deq();
106 let tag
107 = case ( mrespQ.first() ) matches
108 tagged LoadResp .ld : return ld.tag;
109 tagged StoreResp .st : return st.tag;
110 endcase;
112 if ( tag == 0 )
113 resp0Q.enq(mrespQ.first());
114 else
115 resp1Q.enq(mrespQ.first());
117 endrule
119 //-----------------------------------------------------------
120 // Methods
122 interface Server cache0_server;
123 interface Put request = fifofToPut(req0Q);
124 interface Get response = fifoToGet(resp0Q);
125 endinterface
127 interface Server cache1_server;
128 interface Put request = fifofToPut(req1Q);
129 interface Get response = fifoToGet(resp1Q);
130 endinterface
132 interface Client mmem_client;
133 interface Get request = fifoToGet(mreqQ);
134 interface Put response = fifoToPut(mrespQ);
135 endinterface
137 endmodule