src/ieee754/fpcommon/exphigh.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 MultiShiftRMerge
   9
  10
  11 class FPEXPHigh(Elaboratable):
  12
  13     def __init__(self, m_width, e_width):
  14         self.m_width = m_width
  15         self.e_width = e_width
  16         self.ediff = Signal((e_width, True), reset_less=True)
  17
  18         self.m_in = Signal(m_width, reset_less=True)
  19         self.e_in = Signal((e_width, True), reset_less=True)
  20         self.m_out = Signal(m_width, reset_less=True)
  21         self.e_out = Signal((e_width, True), reset_less=True)
  22
  23     def elaborate(self, platform):
  24         m = Module()
  25
  26         espec = (self.e_width, True)
  27         mwid = self.m_width
  28
  29         msr = MultiShiftRMerge(mwid, espec)
  30         m.submodules.multishift_r = msr
  31
  32         m.d.comb += [
  33             # connect multi-shifter to inp/out mantissa (and ediff)
  34             msr.inp.eq(self.m_in),
  35             msr.diff.eq(self.ediff),
  36             self.m_out.eq(msr.m),
  37             self.e_out.eq(self.e_in + self.ediff),
  38         ]
  39
  40
  41         return m
  42
  43