AckNak_Seq_Num
[11:0] | Byte 3 Bit 7:0
Byte 2 Bit 3:0 | For an ACK DLLP:
For good TLPs received with Sequence Number = NEXT_RCV_SEQ count (count before incrementing), use NEXT_RCV_SEQ count - 1 (count after incrementing minus 1). For TLP received with Sequence Number earlier than NEXT_RCV_SEQ count (duplicate TLP), use NEXT_RCV_SEQ count - 1.
For a NAK DLLP:
Associated with a TLP that fails the CRC check, use NEXT_RCV_SEQ count - 1. For a TLP received with Sequence Number later than NEXT_RCV_SEQ count, use NEXT_RCV_SEQ count - 1.
Upon receipt, the transmitter will purge TLPs with equal to and earlier Sequence Numbers and replay the remainder TLPs. |
