src/ieee754/cordic/pipe_data.py

   1 from nmigen import Signal, Const
   2 import math
   3
   4 class CordicInitialData:
   5
   6     def __init__(self, pspec):
   7         ZMAX = pspec.ZMAX
   8         self.z0 = Signal(range(-ZMAX, ZMAX), name="z")     # denormed result
   9
  10     def __iter__(self):
  11         yield from self.z
  12
  13     def eq(self, i):
  14         return [self.z.eq(i.z)]
  15
  16 class CordicData:
  17
  18     def __init__(self, pspec):
  19
  20         M = pspec.M
  21         ZMAX = pspec.ZMAX
  22         self.x = Signal(range(-M, M+1), name="x")   # operand a
  23         self.y = Signal(range(-M, M+1), name="y")   # operand b
  24         self.z = Signal(range(-ZMAX, ZMAX), name="z")     # denormed result
  25
  26     def __iter__(self):
  27         yield from self.x
  28         yield from self.y
  29         yield from self.z
  30
  31     def eq(self, i):
  32         ret = [self.z.eq(i.z), self.x.eq(i.x), self.y.eq(i.y)]
  33         return ret
  34
  35
  36 class CordicPipeSpec:
  37     def __init__(self, fracbits):
  38         self.fracbits = fracbits
  39         self.M = (1 << fracbits)
  40         self.ZMAX = int(round(self.M * math.pi/2))
  41         zm = Const(-self.ZMAX)
  42         self.iterations = zm.width - 1