TLB/CamEntry.py

   1 from nmigen import Module, Signal
   2
   3 class CamEntry:
   4     def __init__(self, key_size, data_size):
   5         # Internal
   6         self.key = Signal(key_size)
   7
   8         # Input
   9         self.write = Signal(1) # Read => 0 Write => 1
  10         self.key_in = Signal(key_size) # Reference key for the CAM
  11         self.data_in = Signal(data_size) # Data input when writing
  12
  13         # Output
  14         self.match = Signal(1) # Result of the internal/input key comparison
  15         self.data = Signal(data_size)
  16
  17
  18     def get_fragment(self, platform=None):
  19         m = Module()
  20         with m.If(self.write == 1):
  21             m.d.sync += [
  22                 self.key.eq(self.key_in),
  23                 self.data.eq(self.data_in),
  24                 self.match.eq(1)
  25             ]
  26         with m.Else():
  27             with m.If(self.key_in == self.key):
  28                 m.d.sync += self.match.eq(0)
  29             with m.Else():
  30                 m.d.sync += self.match.eq(1)
  31
  32         return m