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, id_wid, op_wid):
  18         Object.__init__(self)
  19         self.z = Signal(width, reset_less=True)    # result
  20         self.mid = Signal(id_wid, reset_less=True) # multiplex ID
  21         self.op = Signal(op_wid or 0, reset_less=True) # operand width
  22
  23
  24 class FPPackMod(Elaboratable):
  25
  26     def __init__(self, width, id_wid, op_wid=None):
  27         self.width = width
  28         self.id_wid = id_wid
  29         self.op_wid = op_wid
  30         self.i = self.ispec()
  31         self.o = self.ospec()
  32
  33     def ispec(self):
  34         return FPRoundData(self.width, self.id_wid, self.op_wid)
  35
  36     def ospec(self):
  37         return FPPackData(self.width, self.id_wid, self.op_wid)
  38
  39     def process(self, i):
  40         return self.o
  41
  42     def setup(self, m, in_z):
  43         """ links module to inputs and outputs
  44         """
  45         m.submodules.pack = self
  46         m.d.comb += self.i.eq(in_z)
  47
  48     def elaborate(self, platform):
  49         m = Module()
  50         z = FPNumBaseRecord(self.width, False)
  51         m.submodules.pack_in_z = in_z = FPNumBase(self.i.z)
  52         #m.submodules.pack_out_z = out_z = FPNumOut(z)
  53         m.d.comb += self.o.mid.eq(self.i.mid)
  54         if self.i.op_wid:
  55             m.d.comb += self.o.op.eq(self.i.op)
  56         with m.If(~self.i.out_do_z):
  57             with m.If(in_z.is_overflowed):
  58                 m.d.comb += z.inf(self.i.z.s)
  59             with m.Else():
  60                 m.d.comb += z.create(self.i.z.s, self.i.z.e, self.i.z.m)
  61         with m.Else():
  62             m.d.comb += z.v.eq(self.i.oz)
  63         m.d.comb += self.o.z.eq(z.v)
  64         return m
  65
  66
  67 class FPPack(FPState):
  68
  69     def __init__(self, width, id_wid):
  70         FPState.__init__(self, "pack")
  71         self.mod = FPPackMod(width)
  72         self.out_z = self.ospec()
  73
  74     def ispec(self):
  75         return self.mod.ispec()
  76
  77     def ospec(self):
  78         return self.mod.ospec()
  79
  80     def setup(self, m, in_z):
  81         """ links module to inputs and outputs
  82         """
  83         self.mod.setup(m, in_z)
  84
  85         m.d.sync += self.out_z.v.eq(self.mod.out_z.v)
  86         m.d.sync += self.out_z.mid.eq(self.mod.o.mid)
  87
  88     def action(self, m):
  89         m.next = "pack_put_z"