src/ieee754/add/fpadd/pipeline.py

   1 # IEEE Floating Point Adder (Single Precision)
   2 # Copyright (C) Jonathan P Dawson 2013
   3 # 2013-12-12
   4
   5 from nmigen import Module
   6 from nmigen.cli import main, verilog
   7
   8 from singlepipe import (ControlBase, SimpleHandshake, PassThroughStage)
   9 from multipipe import CombMuxOutPipe
  10 from multipipe import PriorityCombMuxInPipe
  11
  12 from fpcommon.getop import FPADDBaseData
  13 from fpcommon.denorm import FPSCData
  14 from fpcommon.pack import FPPackData
  15 from fpcommon.normtopack import FPNormToPack
  16 from fpadd.specialcases import FPAddSpecialCasesDeNorm
  17 from fpadd.addstages import FPAddAlignSingleAdd
  18
  19 from concurrentunit import ReservationStations, num_bits
  20
  21
  22 class FPADDBasePipe(ControlBase):
  23     def __init__(self, width, id_wid):
  24         ControlBase.__init__(self)
  25         self.pipe1 = FPAddSpecialCasesDeNorm(width, id_wid)
  26         self.pipe2 = FPAddAlignSingleAdd(width, id_wid)
  27         self.pipe3 = FPNormToPack(width, id_wid)
  28
  29         self._eqs = self.connect([self.pipe1, self.pipe2, self.pipe3])
  30
  31     def elaborate(self, platform):
  32         m = ControlBase.elaborate(self, platform)
  33         m.submodules.scnorm = self.pipe1
  34         m.submodules.addalign = self.pipe2
  35         m.submodules.normpack = self.pipe3
  36         m.d.comb += self._eqs
  37         return m
  38
  39
  40 class FPADDMuxInOut(ReservationStations):
  41     """ Reservation-Station version of FPADD pipeline.
  42
  43         * fan-in on inputs (an array of FPADDBaseData: a,b,mid)
  44         * 3-stage adder pipeline
  45         * fan-out on outputs (an array of FPPackData: z,mid)
  46
  47         Fan-in and Fan-out are combinatorial.
  48     """
  49     def __init__(self, width, num_rows):
  50         self.width = width
  51         self.id_wid = num_bits(width)
  52         self.alu = FPADDBasePipe(width, self.id_wid)
  53         ReservationStations.__init__(self, num_rows)
  54
  55     def i_specfn(self):
  56         return FPADDBaseData(self.width, self.id_wid)
  57
  58     def o_specfn(self):
  59         return FPPackData(self.width, self.id_wid)