src/ieee754/fpcommon/corrections.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, Elaboratable
   6 from nmigen.cli import main, verilog
   7 from ieee754.fpcommon.fpbase import FPState, FPNumBase
   8 from .roundz import FPRoundData
   9
  10
  11 class FPCorrectionsMod(Elaboratable):
  12
  13     def __init__(self, pspec):
  14         self.pspec = pspec
  15         self.i = self.ispec()
  16         self.out_z = self.ospec()
  17
  18     def ispec(self):
  19         return FPRoundData(self.pspec)
  20
  21     def ospec(self):
  22         return FPRoundData(self.pspec)
  23
  24     def process(self, i):
  25         return self.out_z
  26
  27     def setup(self, m, i):
  28         """ links module to inputs and outputs
  29         """
  30         m.submodules.corrections = self
  31         m.d.comb += self.i.eq(i)
  32
  33     def elaborate(self, platform):
  34         m = Module()
  35         m.submodules.corr_in_z = in_z = FPNumBase(self.i.z)
  36         #m.submodules.corr_out_z = self.out_z.z
  37         m.d.comb += self.out_z.eq(self.i) # copies mid, z, out_do_z
  38         with m.If(~self.i.out_do_z):
  39             with m.If(in_z.is_denormalised):
  40                 m.d.comb += self.out_z.z.e.eq(self.i.z.N127)
  41         return m
  42
  43
  44 class FPCorrections(FPState):
  45
  46     def __init__(self, width, id_wid):
  47         FPState.__init__(self, "corrections")
  48         self.mod = FPCorrectionsMod(width)
  49         self.out_z = self.ospec()
  50
  51     def ispec(self):
  52         return self.mod.ispec()
  53
  54     def ospec(self):
  55         return self.mod.ospec()
  56
  57     def setup(self, m, in_z):
  58         """ links module to inputs and outputs
  59         """
  60         self.mod.setup(m, in_z)
  61
  62         m.d.sync += self.out_z.eq(self.mod.out_z)
  63         m.d.sync += self.out_z.ctx.eq(self.mod.o.ctx)
  64
  65     def action(self, m):
  66         m.next = "pack"
  67
  68