src/ieee754/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 nmutil.singlepipe import (ControlBase, SimpleHandshake, PassThroughStage)
   9 from nmutil.multipipe import CombMuxOutPipe
  10 from nmutil.multipipe import PriorityCombMuxInPipe
  11 from nmutil.concurrentunit import ReservationStations, num_bits
  12
  13 from ieee754.fpcommon.getop import FPADDBaseData
  14 from ieee754.fpcommon.denorm import FPSCData
  15 from ieee754.fpcommon.pack import FPPackData
  16 from ieee754.fpcommon.normtopack import FPNormToPack
  17 from .specialcases import FPAddSpecialCasesDeNorm
  18 from .addstages import FPAddAlignSingleAdd
  19
  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)