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