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
   6 from nmigen.cli import main, verilog
   7
   8 from nmutil.pipemodbase import PipeModBase
   9 from ieee754.fpcommon.fpbase import FPNumBaseRecord, FPNumBase
  10 from ieee754.fpcommon.roundz import FPRoundData
  11 from ieee754.fpcommon.getop import FPPipeContext
  12 from ieee754.fpcommon.packdata import FPPackData
  13
  14
  15 class FPPackMod(PipeModBase):
  16
  17     def __init__(self, pspec):
  18         super().__init__(pspec, "pack")
  19
  20     def ispec(self):
  21         return FPRoundData(self.pspec)
  22
  23     def ospec(self):
  24         return FPPackData(self.pspec)
  25
  26     def elaborate(self, platform):
  27         m = Module()
  28         comb = m.d.comb
  29
  30         z = FPNumBaseRecord(self.pspec.width, False, name="z")
  31         m.submodules.pack_in_z = in_z = FPNumBase(self.i.z)
  32
  33         with m.If(~self.i.out_do_z):
  34             with m.If(in_z.is_overflowed):
  35                 comb += z.inf(self.i.z.s)
  36             with m.Else():
  37                 comb += z.create(self.i.z.s, self.i.z.e, self.i.z.m)
  38         with m.Else():
  39             comb += z.v.eq(self.i.oz)
  40
  41         comb += self.o.ctx.eq(self.i.ctx)
  42         comb += self.o.z.eq(z.v)
  43
  44         return m