1 # IEEE Floating Point Adder (Single Precision)
2 # Copyright (C) Jonathan P Dawson 2013
5 from nmigen
import Module
, Signal
, Cat
, Mux
, Array
, Const
6 from nmigen
.lib
.coding
import PriorityEncoder
7 from nmigen
.cli
import main
, verilog
10 from fpbase
import FPNumIn
, FPNumOut
, FPOp
, Overflow
, FPBase
, FPNumBase
11 from fpbase
import MultiShiftRMerge
, Trigger
12 from singlepipe
import (ControlBase
, StageChain
, UnbufferedPipeline
,
14 from multipipe
import CombMuxOutPipe
15 from multipipe
import PriorityCombMuxInPipe
17 from fpbase
import FPState
, FPID
18 from fpcommon
.postnormalise
import FPNorm1Data
23 def __init__(self
, width
, id_wid
):
24 self
.z
= FPNumBase(width
, False)
25 self
.out_do_z
= Signal(reset_less
=True)
26 self
.oz
= Signal(width
, reset_less
=True)
27 self
.mid
= Signal(id_wid
, reset_less
=True)
30 return [self
.z
.eq(i
.z
), self
.out_do_z
.eq(i
.out_do_z
), self
.oz
.eq(i
.oz
),
36 def __init__(self
, width
, id_wid
):
40 self
.out_z
= self
.ospec()
43 return FPNorm1Data(self
.width
, self
.id_wid
)
46 return FPRoundData(self
.width
, self
.id_wid
)
51 def setup(self
, m
, i
):
52 m
.submodules
.roundz
= self
53 m
.d
.comb
+= self
.i
.eq(i
)
55 def elaborate(self
, platform
):
57 m
.d
.comb
+= self
.out_z
.eq(self
.i
) # copies mid, z, out_do_z
58 with m
.If(~self
.i
.out_do_z
):
59 with m
.If(self
.i
.roundz
):
60 m
.d
.comb
+= self
.out_z
.z
.m
.eq(self
.i
.z
.m
+ 1) # mantissa up
61 with m
.If(self
.i
.z
.m
== self
.i
.z
.m1s
): # all 1s
62 m
.d
.comb
+= self
.out_z
.z
.e
.eq(self
.i
.z
.e
+ 1) # exponent up
67 class FPRound(FPState
):
69 def __init__(self
, width
, id_wid
):
70 FPState
.__init
__(self
, "round")
71 self
.mod
= FPRoundMod(width
)
72 self
.out_z
= self
.ospec()
75 return self
.mod
.ispec()
78 return self
.mod
.ospec()
80 def setup(self
, m
, i
):
81 """ links module to inputs and outputs
86 m
.d
.sync
+= self
.out_z
.eq(self
.mod
.out_z
)
87 m
.d
.sync
+= self
.out_z
.mid
.eq(self
.mod
.o
.mid
)
90 m
.next
= "corrections"