src/add/fpcommon/pack.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, Signal
   6 from nmigen.cli import main, verilog
   7
   8 from fpbase import FPNumOut
   9 from fpbase import FPState
  10 from fpcommon.roundz import FPRoundData
  11
  12
  13 class FPPackData:
  14
  15     def __init__(self, width, id_wid):
  16         self.z = Signal(width, reset_less=True)
  17         self.mid = Signal(id_wid, reset_less=True)
  18
  19     def eq(self, i):
  20         return [self.z.eq(i.z), self.mid.eq(i.mid)]
  21
  22     def ports(self):
  23         return [self.z, self.mid]
  24
  25
  26 class FPPackMod:
  27
  28     def __init__(self, width, id_wid):
  29         self.width = width
  30         self.id_wid = id_wid
  31         self.i = self.ispec()
  32         self.o = self.ospec()
  33
  34     def ispec(self):
  35         return FPRoundData(self.width, self.id_wid)
  36
  37     def ospec(self):
  38         return FPPackData(self.width, self.id_wid)
  39
  40     def process(self, i):
  41         return self.o
  42
  43     def setup(self, m, in_z):
  44         """ links module to inputs and outputs
  45         """
  46         m.submodules.pack = self
  47         m.d.comb += self.i.eq(in_z)
  48
  49     def elaborate(self, platform):
  50         m = Module()
  51         z = FPNumOut(self.width, False)
  52         m.submodules.pack_in_z = self.i.z
  53         m.submodules.pack_out_z = z
  54         m.d.comb += self.o.mid.eq(self.i.mid)
  55         with m.If(~self.i.out_do_z):
  56             with m.If(self.i.z.is_overflowed):
  57                 m.d.comb += z.inf(self.i.z.s)
  58             with m.Else():
  59                 m.d.comb += z.create(self.i.z.s, self.i.z.e, self.i.z.m)
  60         with m.Else():
  61             m.d.comb += z.v.eq(self.i.oz)
  62         m.d.comb += self.o.z.eq(z.v)
  63         return m
  64
  65
  66 class FPPack(FPState):
  67
  68     def __init__(self, width, id_wid):
  69         FPState.__init__(self, "pack")
  70         self.mod = FPPackMod(width)
  71         self.out_z = self.ospec()
  72
  73     def ispec(self):
  74         return self.mod.ispec()
  75
  76     def ospec(self):
  77         return self.mod.ospec()
  78
  79     def setup(self, m, in_z):
  80         """ links module to inputs and outputs
  81         """
  82         self.mod.setup(m, in_z)
  83
  84         m.d.sync += self.out_z.v.eq(self.mod.out_z.v)
  85         m.d.sync += self.out_z.mid.eq(self.mod.o.mid)
  86
  87     def action(self, m):
  88         m.next = "pack_put_z"