Aggregating ACK DLLPs
The PCIe Controller supports ACK aggregation in certain conditions:
- Typically, the PCIe Controller schedules one ACK DLLP for transmission for each TLP that it receives.
- If the TX is idle, it transmits an ACK DLLP immediately. However, if the TX is busy with a TLP transmission, the ACK DLLP waits till the ongoing TLP is completely transmitted.
- While the ACK DLLP is waiting for transmission, if the TX receives another TLP, the PCIe Controller aggregates the two pending ACK DLLPs into a single ACK DLLP with the higher sequence number.