gary/experiments/arbiter/Top.bsv

package Top;

import MemArbiter::*;
import Vector::*;
import DReg::*;
import DelayLine::*;
import Connectable::*;

typedef UInt#(2) Addr;

(* always_ready *)
interface Top;
   method Action cpu(Bool write, Addr addr);
   method Action debugger(Bool write, Addr addr);
   method Action palette(Addr addr);

   method Action tile1(Addr addr);
   method Action tile2(Addr addr);
   method Action sprite(Addr addr);

   method Bit#(6) grants();
endinterface

(* synthesize, clock_prefix="clk_25mhz", reset_prefix="rst_btn" *)
module mkTop(Top);
   Vector#(6, Reg#(Maybe#(MemArbiterOp#(Addr)))) wrin <- replicateM(mkDReg(tagged Invalid));

   MemArbiter#(3, Addr) portA <- mkPriorityMemArbiter();
   MemArbiter#(3, Addr) portB <- mkRoundRobinMemArbiter();
   mkConnection(portA, portB);

   let arbiters = append(portA.ports, portB.ports);

   Reg#(Vector#(6, Bool)) ok <- mkReg(replicate(False));

   for (Integer i=0; i<6; i=i+1) begin
      rule req (wrin[i] matches tagged Valid .req);
         arbiters[i].request(req);
      endrule
   end

   rule resp;
      function Bool get(MemArbiterServer#(Addr) s);
         return s.grant();
      endfunction
      ok <= map(get, arbiters);
   endrule

   method Action cpu(Bool write, Addr addr);
      wrin[0] <= tagged Valid MemArbiterOp{write: write, addr: addr};
   endmethod

   method Action debugger(Bool write, Addr addr);
      wrin[1] <= tagged Valid MemArbiterOp{write: write, addr: addr};
   endmethod

   method Action palette(Addr addr);
      wrin[2] <= tagged Valid MemArbiterOp{write: False, addr: addr};
   endmethod

   method Action tile1(Addr addr);
      wrin[3] <= tagged Valid MemArbiterOp{write: False, addr: addr};
   endmethod

   method Action tile2(Addr addr);
      wrin[4] <= tagged Valid MemArbiterOp{write: False, addr: addr};
   endmethod

   method Action sprite(Addr addr);
      wrin[5] <= tagged Valid MemArbiterOp{write: False, addr: addr};
   endmethod

   method Bit#(6) grants();
      return pack(ok);
   endmethod
endmodule

endpackage