src/ieee754/fpadd/addstages.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 (StageChain, SimpleHandshake,
   9                         PassThroughStage)
  10
  11 from fpbase import FPState
  12 from ieee754.fpcommon.denorm import FPSCData
  13 from ieee754.fpcommon.postcalc import FPAddStage1Data
  14 from .align import FPAddAlignSingleMod
  15 from .add0 import FPAddStage0Mod
  16 from .add1 import FPAddStage1Mod
  17
  18
  19 class FPAddAlignSingleAdd(FPState, SimpleHandshake):
  20
  21     def __init__(self, width, id_wid):
  22         FPState.__init__(self, "align")
  23         self.width = width
  24         self.id_wid = id_wid
  25         SimpleHandshake.__init__(self, self) # pipeline is its own stage
  26         self.a1o = self.ospec()
  27
  28     def ispec(self):
  29         return FPSCData(self.width, self.id_wid)
  30
  31     def ospec(self):
  32         return FPAddStage1Data(self.width, self.id_wid) # AddStage1 ospec
  33
  34     def setup(self, m, i):
  35         """ links module to inputs and outputs
  36         """
  37
  38         # chain AddAlignSingle, AddStage0 and AddStage1
  39         mod = FPAddAlignSingleMod(self.width, self.id_wid)
  40         a0mod = FPAddStage0Mod(self.width, self.id_wid)
  41         a1mod = FPAddStage1Mod(self.width, self.id_wid)
  42
  43         chain = StageChain([mod, a0mod, a1mod])
  44         chain.setup(m, i)
  45
  46         self.o = a1mod.o
  47
  48     def process(self, i):
  49         return self.o
  50
  51     def action(self, m):
  52         m.d.sync += self.a1o.eq(self.process(None))
  53         m.next = "normalise_1"
  54
  55