FIFOFixer.md

Rocket/tilelink/FIFOFixer

A FIFO order checker.

---

class TLFIFOFixer

class TLFIFOFixer(implicit p: Parameters) extends LazyModule

FIFO order: For a client whose source id is a range > 1 and asks for the FIFO order, all TileLink transactions belonging to the same source id should proceed in sequential order. To be specific, an A channel packet can be emitted only when either the previous A channel packets belongs to the same id (a burst) or all previous A channel packets have been responded by a D channel packets (a fresh transaction).

When the FIFO order is requested and violated, stall the TileLink channel (hardware deadlock).

• node TLAdapterNode the diplomacy object to record port connections for module generation.
• module LazyModuleImp
  • io Bundle module I/O ports:
    in HeterogeneousBag[TLBundle] input ports.
    out HeterogeneousBag[TLBundle] output ports.
    
  • a_id Seq[UInt] get the target fifoId using the address for channel A.
  • a_nid UInt high when no fifoId is found.
  • a_first Bool whether it is the first beat in a burst.
  • d_first Bool whether it is the first beat in a burst.
  • stalls Seq[Bool] whether the incoming packet violate any of the FIFO order rules.

object TLFIFOFixer

• apply (x:TLOutwardNode) => TLOutwardNode wrap an outward node with a fixer.

_{Last updated: 19/07/2017
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