src/lib/ClockDiv.bsv

   1 package ClockDiv;
   2   /*=== Project imports ==*/
   3   import Clocks::*;
   4   /*======================*/
   5   // =========================== Clock divider module ================ //
   6   interface Ifc_ClockDiv#(numeric type width);
   7     interface Clock slowclock;
   8     method Action divisor(Bit#(width) in);
   9   endinterface
  10
  11   module mkClockDiv(Ifc_ClockDiv#(width));
  12     let defclock <- exposeCurrentClock;
  13     Reg#(Bit#(1)) clk <- mkReg(0);
  14     Reg#(Bit#(width)) rg_divisor <- mkReg(0);
  15     Reg#(Bit#(width)) rg_counter <- mkReg(0);
  16     MakeClockIfc#(Bit#(1)) new_clock <- mkUngatedClock(0);
  17     MuxClkIfc clock_selector <- mkUngatedClockMux(new_clock.new_clk,defclock);
  18     Bool clockmux_sel = rg_divisor!=0;
  19     rule increment_counter;
  20       if(rg_divisor!=0 && rg_counter >= rg_divisor)begin
  21         rg_counter <= 0;
  22         clk <= ~ clk;
  23       end
  24       else
  25         rg_counter <= rg_counter + 1;
  26     endrule
  27
  28     rule generate_clock;
  29       new_clock.setClockValue(clk);
  30     endrule
  31
  32     rule select_clock;
  33       clock_selector.select(clockmux_sel);
  34     endrule
  35
  36     method Action divisor(Bit#(width) in);
  37       rg_divisor <= in != 0 ? in - 1 : 0;
  38     endmethod
  39
  40     interface slowclock=clock_selector.clock_out;
  41   endmodule
  42   // ============================================================== //
  43
  44 endpackage