src/ieee754/fpcommon/pscdata.py

   1 """IEEE754 Floating Point Library
   2
   3 Copyright (C) 2019 Luke Kenneth Casson Leighton <lkcl@lkcl.net>
   4
   5 """
   6
   7 from nmigen import Signal
   8 from ieee754.fpcommon.fpbase import FPNumBaseRecord
   9 from ieee754.fpcommon.getop import FPPipeContext
  10
  11
  12 class FPSCData:
  13
  14     def __init__(self, pspec, m_extra):
  15         width = pspec.width
  16         # NOTE: difference between z and oz is that oz is created by
  17         # special-cases module(s) and will propagate, along with its
  18         # "bypass" signal out_do_z, through the pipeline, *disabling*
  19         # all processing of all subsequent stages.
  20         self.a = FPNumBaseRecord(width, m_extra, name="a")   # operand a
  21         self.b = FPNumBaseRecord(width, m_extra, name="b")   # operand b
  22         self.z = FPNumBaseRecord(width, False, name="z")     # denormed result
  23         self.oz = Signal(width, reset_less=True)   # "finished" (bypass) result
  24         self.out_do_z = Signal(reset_less=True)    # "bypass" enabled
  25         self.ctx = FPPipeContext(pspec)
  26         self.muxid = self.ctx.muxid
  27
  28     def __iter__(self):
  29         yield from self.a
  30         yield from self.b
  31         yield from self.z
  32         yield self.oz
  33         yield self.out_do_z
  34         yield from self.ctx
  35
  36     def eq(self, i):
  37         ret = [self.z.eq(i.z), self.out_do_z.eq(i.out_do_z), self.oz.eq(i.oz),
  38                self.a.eq(i.a), self.b.eq(i.b), self.ctx.eq(i.ctx)]
  39         return ret