src/soc/fu/mul/pipeline.py

   1 from nmutil.singlepipe import ControlBase
   2 from nmutil.pipemodbase import PipeModBaseChain
   3 from soc.fu.div.input_stage import DivMulInputStage
   4 from soc.fu.mul.output_stage import DivMulOutputStage
   5 from soc.fu.mul.pre_stage import MulMainStage1
   6 from soc.fu.mul.main_stage import MulMainStage2
   7 from soc.fu.mul.post_stage import MulMainStage3
   8
   9
  10 class MulStages1(PipeModBaseChain):
  11     def get_chain(self):
  12         inp = DivMulInputStage(self.pspec)   # a-invert (no carry)
  13         main = MulMainStage1(self.pspec)  # detect signed/32-bit
  14         return [inp, main]
  15
  16
  17 class MulStages2(PipeModBaseChain):
  18     def get_chain(self):
  19         main2 = MulMainStage2(self.pspec) # actual multiply
  20         return [main2]
  21
  22
  23 class MulStages3(PipeModBaseChain):
  24     def get_chain(self):
  25         main3 = MulMainStage3(self.pspec) # select output bits, invert, set ov
  26         out = DivMulOutputStage(self.pspec)  # do CR, XER and out-invert etc.
  27         return [main3, out]
  28
  29
  30 class MulBasePipe(ControlBase):
  31     def __init__(self, pspec):
  32         ControlBase.__init__(self)
  33         self.pspec = pspec
  34         self.pipe1 = MulStages1(pspec)
  35         self.pipe2 = MulStages2(pspec)
  36         self.pipe3 = MulStages3(pspec)
  37         self._eqs = self.connect([self.pipe1, self.pipe2, self.pipe3])
  38
  39     def elaborate(self, platform):
  40         m = ControlBase.elaborate(self, platform)
  41         m.submodules.mul_pipe1 = self.pipe1
  42         m.submodules.mul_pipe2 = self.pipe2
  43         m.submodules.mul_pipe3 = self.pipe3
  44         m.d.comb += self._eqs
  45         return m