src/ieee754/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, Elaboratable
   6 from nmigen.cli import main, verilog
   7
   8 from ieee754.fpcommon.fpbase import FPNumOut, FPNumBaseRecord, FPNumBase
   9 from ieee754.fpcommon.fpbase import FPState
  10 from .roundz import FPRoundData
  11 from nmutil.singlepipe import Object
  12 from ieee754.fpcommon.getop import FPBaseData
  13
  14
  15 class FPPackData(Object):
  16
  17     def __init__(self, width, pspec):
  18         Object.__init__(self)
  19         self.z = Signal(width, reset_less=True)    # result
  20         self.ctx = FPBaseData(width, pspec)
  21         self.mid = self.ctx.mid
  22
  23 class FPPackMod(Elaboratable):
  24
  25     def __init__(self, width, pspec):
  26         self.width = width
  27         self.pspec = pspec
  28         self.i = self.ispec()
  29         self.o = self.ospec()
  30
  31     def ispec(self):
  32         return FPRoundData(self.width, self.pspec)
  33
  34     def ospec(self):
  35         return FPPackData(self.width, self.pspec)
  36
  37     def process(self, i):
  38         return self.o
  39
  40     def setup(self, m, in_z):
  41         """ links module to inputs and outputs
  42         """
  43         m.submodules.pack = self
  44         m.d.comb += self.i.eq(in_z)
  45
  46     def elaborate(self, platform):
  47         m = Module()
  48         z = FPNumBaseRecord(self.width, False)
  49         m.submodules.pack_in_z = in_z = FPNumBase(self.i.z)
  50         #m.submodules.pack_out_z = out_z = FPNumOut(z)
  51         m.d.comb += self.o.ctx.eq(self.i.ctx)
  52         with m.If(~self.i.out_do_z):
  53             with m.If(in_z.is_overflowed):
  54                 m.d.comb += z.inf(self.i.z.s)
  55             with m.Else():
  56                 m.d.comb += z.create(self.i.z.s, self.i.z.e, self.i.z.m)
  57         with m.Else():
  58             m.d.comb += z.v.eq(self.i.oz)
  59         m.d.comb += self.o.z.eq(z.v)
  60         return m
  61
  62
  63 class FPPack(FPState):
  64
  65     def __init__(self, width, id_wid):
  66         FPState.__init__(self, "pack")
  67         self.mod = FPPackMod(width)
  68         self.out_z = self.ospec()
  69
  70     def ispec(self):
  71         return self.mod.ispec()
  72
  73     def ospec(self):
  74         return self.mod.ospec()
  75
  76     def setup(self, m, in_z):
  77         """ links module to inputs and outputs
  78         """
  79         self.mod.setup(m, in_z)
  80
  81         m.d.sync += self.out_z.v.eq(self.mod.out_z.v)
  82         m.d.sync += self.out_z.ctx.eq(self.mod.o.ctx)
  83
  84     def action(self, m):
  85         m.next = "pack_put_z"