src/ieee754/cordic/pipe_data.py

   1 from nmigen import Signal, Const
   2 from nmutil.dynamicpipe import SimpleHandshakeRedir
   3 import math
   4
   5
   6 class CordicInitialData:
   7
   8     def __init__(self, pspec):
   9         ZMAX = pspec.ZMAX
  10         self.z0 = Signal(range(-ZMAX, ZMAX), name="z")     # denormed result
  11
  12     def __iter__(self):
  13         yield from self.z
  14
  15     def eq(self, i):
  16         return [self.z0.eq(i.z0)]
  17
  18
  19 class CordicData:
  20
  21     def __init__(self, pspec):
  22
  23         M = pspec.M
  24         ZMAX = pspec.ZMAX
  25         self.x = Signal(range(-M, M+1), name="x")   # operand a
  26         self.y = Signal(range(-M, M+1), name="y")   # operand b
  27         self.z = Signal(range(-ZMAX, ZMAX), name="z")     # denormed result
  28
  29     def __iter__(self):
  30         yield from self.x
  31         yield from self.y
  32         yield from self.z
  33
  34     def eq(self, i):
  35         ret = [self.z.eq(i.z), self.x.eq(i.x), self.y.eq(i.y)]
  36         return ret
  37
  38
  39 class CordicPipeSpec:
  40     def __init__(self, fracbits, rounds_per_stage):
  41         self.fracbits = fracbits
  42         # Number of cordic operations per pipeline stage
  43         self.rounds_per_stage = rounds_per_stage
  44         self.M = (1 << fracbits)
  45         self.ZMAX = int(round(self.M * math.pi/2))
  46         zm = Const(-self.ZMAX)
  47         self.iterations = zm.width - 1
  48
  49         self.pipekls = SimpleHandshakeRedir
  50         self.stage = None