Scrambler.bsv
上传用户:aoptech
上传日期:2014-09-22
资源大小:784k
文件大小:2k
- // The MIT License
- //
- // Copyright (c) 2006 Nirav Dave (ndave@csail.mit.edu)
- //
- // Permission is hereby granted, free of charge, to any person obtaining a copy
- // of this software and associated documentation files (the "Software"), to deal
- // in the Software without restriction, including without limitation the rights
- // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- // copies of the Software, and to permit persons to whom the Software is
- // furnished to do so, subject to the following conditions:
- //
- // The above copyright notice and this permission notice shall be included in
- // all copies or substantial portions of the Software.
- //
- // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- // THE SOFTWARE.
- // *************************************************************************
- // Scrambler.bsv
- // *************************************************************************
- import DataTypes::*;
- import Interfaces::*;
- import LibraryFunctions::*;
- import FIFO::*;
- interface Scrambler#(type n);
- //inputs
- method Action fromControl(RateData#(n) x);
- //outputs
- method ActionValue#(RateData#(n)) toEncoder();
- endinterface
- (* synthesize *)
- module mkScrambler_48(Scrambler#(24));
- let _s <- mkScrambler();
- return (_s);
- endmodule
- module mkScrambler(Scrambler#(n));
- Reg#(Bit#(7)) seqR <- mkRegU;
- FIFO#(RateData#(n)) outQ <- mkFIFO();
- method Action fromControl(RateData#(n) x);
- Bit#(7) headSeq = case (x.rate)
- R1 : return 7'b1001011;
- R2 : return 7'b1001011;
- R4 : return 7'b1001011;
- RNone: return seqR;
- endcase;
-
- Bit#(7) scram_seq = headSeq;
-
- Bit#(1) newS;
- Bit#(n) inData = x.data;
- Bit#(n) outData = 0;
-
- for(Integer i = 0; i < valueOf(n); i = i + 1)
- begin
- newS = scram_seq[0] ^ scram_seq[3];
- outData[i] = newS ^ inData[i];
- scram_seq = {newS,scram_seq[6:1]};
- end
-
- outQ.enq(RateData{
- rate: x.rate,
- data: outData
- });
-
- endmethod
- method ActionValue#(RateData#(n)) toEncoder();
- outQ.deq();
- return(outQ.first());
- endmethod
- endmodule