src/soc/fu/branch/pipeline.py

   1 from nmutil.singlepipe import ControlBase
   2 from nmutil.pipemodbase import PipeModBaseChain
   3 from soc.fu.branch.main_stage import BranchMainStage
   4 from nmutil.pipemodbase import PipeModBase
   5 from soc.fu.branch.pipe_data import BranchInputData
   6 from nmigen import Module
   7
   8 # gives a 1-clock delay to stop combinatorial link between in and out
   9 class DummyBranchStage(PipeModBase):
  10     def __init__(self, pspec): super().__init__(pspec, "dummy")
  11     def ispec(self): return BranchInputData(self.pspec)
  12     def ospec(self): return BranchInputData(self.pspec)
  13
  14     def elaborate(self, platform):
  15         m = Module()
  16         m.d.comb += self.o.eq(self.i) # pass-through output
  17         return m
  18
  19 class BranchDummyStages(PipeModBaseChain):
  20     def get_chain(self):
  21         dummy = DummyBranchStage(self.pspec)
  22         return [dummy]
  23
  24
  25 class BranchStages(PipeModBaseChain):
  26     def get_chain(self):
  27         main = BranchMainStage(self.pspec)
  28         return [main]
  29
  30
  31 class BranchBasePipe(ControlBase):
  32     def __init__(self, pspec):
  33         ControlBase.__init__(self)
  34         self.pspec = pspec
  35         self.pipe1 = BranchDummyStages(pspec)
  36         self.pipe2 = BranchStages(pspec)
  37         self._eqs = self.connect([self.pipe1, self.pipe2])
  38
  39     def elaborate(self, platform):
  40         m = ControlBase.elaborate(self, platform)
  41         m.submodules.pipe1 = self.pipe1
  42         m.submodules.pipe2 = self.pipe2
  43         m.d.comb += self._eqs
  44         return m