302c302,303
< def addTwoLevelCacheHierarchy(self, ic, dc, l2c, iwc = None, dwc = None):
---
> def addTwoLevelCacheHierarchy(self, ic, dc, l2c, iwc=None, dwc=None,
> xbar=None):
304c305
< self.toL2Bus = L2XBar()
---
> self.toL2Bus = xbar if xbar else L2XBar()