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 fpbase import FPState
   8 from fpcommon.roundz import FPRoundData
   9
  10
  11 class FPCorrectionsMod(Elaboratable):
  12
  13     def __init__(self, width, id_wid):
  14         self.width = width
  15         self.id_wid = id_wid
  16         self.i = self.ispec()
  17         self.out_z = self.ospec()
  18
  19     def ispec(self):
  20         return FPRoundData(self.width, self.id_wid)
  21
  22     def ospec(self):
  23         return FPRoundData(self.width, self.id_wid)
  24
  25     def process(self, i):
  26         return self.out_z
  27
  28     def setup(self, m, i):
  29         """ links module to inputs and outputs
  30         """
  31         m.submodules.corrections = self
  32         m.d.comb += self.i.eq(i)
  33
  34     def elaborate(self, platform):
  35         m = Module()
  36         m.submodules.corr_in_z = self.i.z
  37         m.submodules.corr_out_z = self.out_z.z
  38         m.d.comb += self.out_z.eq(self.i) # copies mid, z, out_do_z
  39         with m.If(~self.i.out_do_z):
  40             with m.If(self.i.z.is_denormalised):
  41                 m.d.comb += self.out_z.z.e.eq(self.i.z.N127)
  42         return m
  43
  44
  45 class FPCorrections(FPState):
  46
  47     def __init__(self, width, id_wid):
  48         FPState.__init__(self, "corrections")
  49         self.mod = FPCorrectionsMod(width)
  50         self.out_z = self.ospec()
  51
  52     def ispec(self):
  53         return self.mod.ispec()
  54
  55     def ospec(self):
  56         return self.mod.ospec()
  57
  58     def setup(self, m, in_z):
  59         """ links module to inputs and outputs
  60         """
  61         self.mod.setup(m, in_z)
  62
  63         m.d.sync += self.out_z.eq(self.mod.out_z)
  64         m.d.sync += self.out_z.mid.eq(self.mod.o.mid)
  65
  66     def action(self, m):
  67         m.next = "pack"
  68
  69