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, width, id_wid, op_wid=None):
  14         self.width = width
  15         self.id_wid = id_wid
  16         self.op_wid = op_wid # operand width
  17         self.i = self.ispec()
  18         self.out_z = self.ospec()
  19
  20     def ispec(self):
  21         return FPRoundData(self.width, self.id_wid, self.op_wid)
  22
  23     def ospec(self):
  24         return FPRoundData(self.width, self.id_wid, self.op_wid)
  25
  26     def process(self, i):
  27         return self.out_z
  28
  29     def setup(self, m, i):
  30         """ links module to inputs and outputs
  31         """
  32         m.submodules.corrections = self
  33         m.d.comb += self.i.eq(i)
  34
  35     def elaborate(self, platform):
  36         m = Module()
  37         m.submodules.corr_in_z = in_z = FPNumBase(self.i.z)
  38         #m.submodules.corr_out_z = self.out_z.z
  39         m.d.comb += self.out_z.eq(self.i) # copies mid, z, out_do_z
  40         with m.If(~self.i.out_do_z):
  41             with m.If(in_z.is_denormalised):
  42                 m.d.comb += self.out_z.z.e.eq(self.i.z.N127)
  43         return m
  44
  45
  46 class FPCorrections(FPState):
  47
  48     def __init__(self, width, id_wid):
  49         FPState.__init__(self, "corrections")
  50         self.mod = FPCorrectionsMod(width)
  51         self.out_z = self.ospec()
  52
  53     def ispec(self):
  54         return self.mod.ispec()
  55
  56     def ospec(self):
  57         return self.mod.ospec()
  58
  59     def setup(self, m, in_z):
  60         """ links module to inputs and outputs
  61         """
  62         self.mod.setup(m, in_z)
  63
  64         m.d.sync += self.out_z.eq(self.mod.out_z)
  65         m.d.sync += self.out_z.mid.eq(self.mod.o.mid)
  66
  67     def action(self, m):
  68         m.next = "pack"
  69
  70