src/add/fpcommon/normtopack.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, Signal, Cat, Mux, Array, Const
   6 from nmigen.lib.coding import PriorityEncoder
   7 from nmigen.cli import main, verilog
   8 from math import log
   9
  10 from fpbase import FPNumIn, FPNumOut, FPOp, Overflow, FPBase, FPNumBase
  11 from fpbase import MultiShiftRMerge, Trigger
  12 from singlepipe import (ControlBase, StageChain, UnbufferedPipeline,
  13                         PassThroughStage)
  14 from multipipe import CombMuxOutPipe
  15 from multipipe import PriorityCombMuxInPipe
  16
  17 from fpbase import FPState, FPID
  18 from fpcommon.postcalc import FPAddStage1Data
  19 from fpcommon.postnormalise import FPNorm1ModSingle
  20 from fpcommon.roundz import FPRoundMod
  21 from fpcommon.corrections import FPCorrectionsMod
  22 from fpcommon.pack import FPPackData, FPPackMod
  23
  24
  25 class FPNormToPack(FPState, UnbufferedPipeline):
  26
  27     def __init__(self, width, id_wid):
  28         FPState.__init__(self, "normalise_1")
  29         self.id_wid = id_wid
  30         self.width = width
  31         UnbufferedPipeline.__init__(self, self) # pipeline is its own stage
  32
  33     def ispec(self):
  34         return FPAddStage1Data(self.width, self.id_wid) # Norm1ModSingle ispec
  35
  36     def ospec(self):
  37         return FPPackData(self.width, self.id_wid) # FPPackMod ospec
  38
  39     def setup(self, m, i):
  40         """ links module to inputs and outputs
  41         """
  42
  43         # Normalisation, Rounding Corrections, Pack - in a chain
  44         nmod = FPNorm1ModSingle(self.width, self.id_wid)
  45         rmod = FPRoundMod(self.width, self.id_wid)
  46         cmod = FPCorrectionsMod(self.width, self.id_wid)
  47         pmod = FPPackMod(self.width, self.id_wid)
  48         chain = StageChain([nmod, rmod, cmod, pmod])
  49         chain.setup(m, i)
  50         self.out_z = pmod.ospec()
  51
  52         self.o = pmod.o
  53
  54     def process(self, i):
  55         return self.o
  56
  57     def action(self, m):
  58         m.d.sync += self.out_z.eq(self.process(None))
  59         m.next = "pack_put_z"