//----------------------------------------------------------------------//// The MIT License // // Copyright (c) 2007 Alfred Man Cheuk Ng, mcn02@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.//----------------------------------------------------------------------//import DataTypes::*;import Interfaces::*;import Controls::*;import FIFO::*;import GetPut::*;import LibraryFunctions::*;import Vector::*;function a choose(Bool b, a x, a y);   return b ? x : y;endfunctionfunction Tuple2#(Bit#(1),Bit#(shifter_sz))    scramble(Bit#(shifter_sz) genPoly,	    Tuple2#(Bit#(1),Bit#(shifter_sz)) tup,	    Bit#(1) inBit)   provisos (Add#(1,xxA,shifter_sz));   let curSeq = tpl_2(tup);   let fback = genXORFeedback(genPoly,curSeq);   Vector#(shifter_sz,Bit#(1)) oVec = shiftInAt0(unpack(curSeq),fback);   let oSeq = pack(oVec);   let oBit = fback ^ inBit;   return tuple2(oBit,oSeq);endfunctionmodule mkScrambler#(function ScramblerCtrl#(n,shifter_sz) 		       mapCtrl(i_ctrl_t ctrl),                    function o_ctrl_t convertCtrl(i_ctrl_t ctrl),                    Bit#(shifter_sz) genPoly)   (Scrambler#(i_ctrl_t,o_ctrl_t,n,n))   provisos(Add#(1,xxA,shifter_sz),	    Bits#(i_ctrl_t,i_ctrl_sz),	    Bits#(o_ctrl_t,o_ctrl_sz));      // state elements   Reg#(Bit#(shifter_sz)) shiftReg <- mkRegU;   FIFO#(ScramblerMesg#(i_ctrl_t,n)) inQ <- mkLFIFO;   FIFO#(EncoderMesg#(o_ctrl_t,n))  outQ <- mkSizedFIFO(2);   // rule   rule execScramble(True);      let mesg = inQ.first;      let ctrl = mesg.control;      let data = mesg.data;      Vector#(n,Bit#(1)) iDataVec = unpack(data);      let sCtrl = mapCtrl(ctrl);      let initTup = tuple2(0,fromMaybe(shiftReg,sCtrl.seed));      let oCtrl = convertCtrl(ctrl);      let oVec = sscanl(scramble(genPoly),initTup,iDataVec);      match {.oDataVec,.seqVec} = unzip(oVec);      Vector#(n,Bool) bypassVec = unpack(sCtrl.bypass);      let oData = pack(map3(choose,bypassVec,iDataVec,oDataVec));      inQ.deq;      shiftReg <= seqVec[valueOf(n)-1]; // last seq is what we want      outQ.enq(Mesg{control:oCtrl, data:oData});   endrule      //methods   interface in = fifoToPut(inQ);   interface out = fifoToGet(outQ);endmodule