The PCI Express (PCI_EXP) interface consists of differential transmit and receive
pairs organized in multiple lanes. A PCI Express lane consists of a pair of transmit
differential signals (pci_exp_txp, pci_exp_txn)
and a pair of receive differential signals (pci_exp_rxp,
pci_exp_rxn). The 1-lane core supports only Lane 0, the 2-lane
core supports lanes 0–1, the 4-lane core supports lanes 0-3, the 8-lane core
supports lanes 0–7, and the 16-lane core supports lanes 0-15. Transmit and receive
signals of the PCI_EXP interface are defined in the following table.
| Lane Number | Name | I/O | Description |
|---|---|---|---|
| 1-Lane Cores | |||
| 0 | pci_exp_txp0 | O | PCI Express Transmit Positive: Serial Differential Output 0 (+) |
| pci_exp_txn0 | O | PCI Express Transmit Negative: Serial Differential Output 0 (–) | |
| pci_exp_rxp0 | I | PCI Express Receive Positive: Serial Differential Input 0 (+) | |
| pci_exp_rxn0 | I | PCI Express Receive Negative: Serial Differential Input 0 (–) | |
| 2-Lane Cores | |||
| 0 | pci_exp_txp0 | O | PCI Express Transmit Positive: Serial Differential Output 0 (+) |
| pci_exp_txn0 | O | PCI Express Transmit Negative: Serial Differential Output 0 (–) | |
| pci_exp_rxp0 | I | PCI Express Receive Positive: Serial Differential Input 0 (+) | |
| pci_exp_rxn0 | I | PCI Express Receive Negative: Serial Differential Input 0 (–) | |
| 1 | pci_exp_txp1 | O | PCI Express Transmit Positive: Serial Differential Output 1 (+) |
| pci_exp_txn1 | O | PCI Express Transmit Negative: Serial Differential Output 1 (–) | |
| pci_exp_rxp1 | I | PCI Express Receive Positive: Serial Differential Input 1 (+) | |
| pci_exp_rxn1 | I | PCI Express Receive Negative: Serial Differential Input 1 (–) | |
| 4-Lane Cores | |||
| 0 | pci_exp_txp0 | O | PCI Express Transmit Positive: Serial Differential Output 0 (+) |
| pci_exp_txn0 | O | PCI Express Transmit Negative: Serial Differential Output 0 (–) | |
| pci_exp_rxp0 | I | PCI Express Receive Positive: Serial Differential Input 0 (+) | |
| pci_exp_rxn0 | I | PCI Express Receive Negative: Serial Differential Input 0 (–) | |
| 1 | pci_exp_txp1 | O | PCI Express Transmit Positive: Serial Differential Output 1 (+) |
| pci_exp_txn1 | O | PCI Express Transmit Negative: Serial Differential Output 1 (–) | |
| pci_exp_rxp1 | I | PCI Express Receive Positive: Serial Differential Input 1 (+) | |
| pci_exp_rxn1 | I | PCI Express Receive Negative: Serial Differential Input 1 (–) | |
| 2 | pci_exp_txp2 | O | PCI Express Transmit Positive: Serial Differential Output 2 (+) |
| pci_exp_txn2 | O | PCI Express Transmit Negative: Serial Differential Output 2 (–) | |
| pci_exp_rxp2 | I | PCI Express Receive Positive: Serial Differential Input 2 (+) | |
| pci_exp_rxn2 | I | PCI Express Receive Negative: Serial Differential Input 2 (–) | |
| 3 | pci_exp_txp3 | O | PCI Express Transmit Positive: Serial Differential Output 3 (+) |
| pci_exp_txn3 | O | PCI Express Transmit Negative: Serial Differential Output 3 (–) | |
| pci_exp_rxp3 | I | PCI Express Receive Positive: Serial Differential Input 3 (+) | |
| pci_exp_rxn3 | I | PCI Express Receive Negative: Serial Differential Input 3 (–) | |
| 8-Lane Cores | |||
| 0 | pci_exp_txp0 | O | PCI Express Transmit Positive: Serial Differential Output 0 (+) |
| pci_exp_txn0 | O | PCI Express Transmit Negative: Serial Differential Output 0 (–) | |
| pci_exp_rxp0 | I | PCI Express Receive Positive: Serial Differential Input 0 (+) | |
| pci_exp_rxn0 | I | PCI Express Receive Negative: Serial Differential Input 0 (–) | |
| 1 | pci_exp_txp1 | O | PCI Express Transmit Positive: Serial Differential Output 1 (+) |
| pci_exp_txn1 | O | PCI Express Transmit Negative: Serial Differential Output 1 (–) | |
| pci_exp_rxp1 | I | PCI Express Receive Positive: Serial Differential Input 1 (+) | |
| pci_exp_rxn1 | I | PCI Express Receive Negative: Serial Differential Input 1 (–) | |
| 2 | pci_exp_txp2 | O | PCI Express Transmit Positive: Serial Differential Output 2 (+) |
| pci_exp_txn2 | O | PCI Express Transmit Negative: Serial Differential Output 2 (–) | |
| pci_exp_rxp2 | I | PCI Express Receive Positive: Serial Differential Input 2 (+) | |
| pci_exp_rxn2 | I | PCI Express Receive Negative: Serial Differential Input 2 (–) | |
| 3 | pci_exp_txp3 | O | PCI Express Transmit Positive: Serial Differential Output 3 (+) |
| pci_exp_txn3 | O | PCI Express Transmit Negative: Serial Differential Output 3 (–) | |
| pci_exp_rxp3 | I | PCI Express Receive Positive: Serial Differential Input 3 (+) | |
| pci_exp_rxn3 | I | PCI Express Receive Negative: Serial Differential Input 3 (–) | |
| 4 | pci_exp_txp4 | O | PCI Express Transmit Positive: Serial Differential Output 4 (+) |
| pci_exp_txn4 | O | PCI Express Transmit Negative: Serial Differential Output 4 (–) | |
| pci_exp_rxp4 | I | PCI Express Receive Positive: Serial Differential Input 4 (+) | |
| pci_exp_rxn4 | I | PCI Express Receive Negative: Serial Differential Input 4 (–) | |
| 5 | pci_exp_txp5 | O | PCI Express Transmit Positive: Serial Differential Output 5 (+) |
| pci_exp_txn5 | O | PCI Express Transmit Negative: Serial Differential Output 5 (–) | |
| pci_exp_rxp5 | I | PCI Express Receive Positive: Serial Differential Input 5 (+) | |
| pci_exp_rxn5 | I | PCI Express Receive Negative: Serial Differential Input 5 (–) | |
| 6 | pci_exp_txp6 | O | PCI Express Transmit Positive: Serial Differential Output 6 (+) |
| pci_exp_txn6 | O | PCI Express Transmit Negative: Serial Differential Output 6 (–) | |
| pci_exp_rxp6 | I | PCI Express Receive Positive: Serial Differential Input 6 (+) | |
| pci_exp_rxn6 | I | PCI Express Receive Negative: Serial Differential Input 6 (–) | |
| 7 | pci_exp_txp7 | O | PCI Express Transmit Positive: Serial Differential Output 7 (+) |
| pci_exp_txn7 | O | PCI Express Transmit Negative: Serial Differential Output 7 (–) | |
| pci_exp_rxp7 | I | PCI Express Receive Positive: Serial Differential Input 7 (+) | |
| pci_exp_rxn7 | I | PCI Express Receive Negative: Serial Differential Input 7 (–) | |
| 16-Lane Cores | |||
| 0 | pci_exp_txp0 | O | PCI Express Transmit Positive: Serial Differential Output 0 (+) |
| pci_exp_txn0 | O | PCI Express Transmit Negative: Serial Differential Output 0 (–) | |
| pci_exp_rxp0 | I | PCI Express Receive Positive: Serial Differential Input 0 (+) | |
| pci_exp_rxn0 | I | PCI Express Receive Negative: Serial Differential Input 0 (–) | |
| 1 | pci_exp_txp1 | O | PCI Express Transmit Positive: Serial Differential Output 1 (+) |
| pci_exp_txn1 | O | PCI Express Transmit Negative: Serial Differential Output 1 (–) | |
| pci_exp_rxp1 | I | PCI Express Receive Positive: Serial Differential Input 1 (+) | |
| pci_exp_rxn1 | I | PCI Express Receive Negative: Serial Differential Input 1 (–) | |
| 2 | pci_exp_txp2 | O | PCI Express Transmit Positive: Serial Differential Output 2 (+) |
| pci_exp_txn2 | O | PCI Express Transmit Negative: Serial Differential Output 2 (–) | |
| pci_exp_rxp2 | I | PCI Express Receive Positive: Serial Differential Input 2 (+) | |
| pci_exp_rxn2 | I | PCI Express Receive Negative: Serial Differential Input 2 (–) | |
| 3 | pci_exp_txp3 | O | PCI Express Transmit Positive: Serial Differential Output 3 (+) |
| pci_exp_txn3 | O | PCI Express Transmit Negative: Serial Differential Output 3 (–) | |
| pci_exp_rxp3 | I | PCI Express Receive Positive: Serial Differential Input 3 (+) | |
| pci_exp_rxn3 | I | PCI Express Receive Negative: Serial Differential Input 3 (–) | |
| 4 | pci_exp_txp4 | O | PCI Express Transmit Positive: Serial Differential Output 4 (+) |
| pci_exp_txn4 | O | PCI Express Transmit Negative: Serial Differential Output 4 (–) | |
| pci_exp_rxp4 | I | PCI Express Receive Positive: Serial Differential Input 4 (+) | |
| pci_exp_rxn4 | I | PCI Express Receive Negative: Serial Differential Input 4 (–) | |
| 5 | pci_exp_txp5 | O | PCI Express Transmit Positive: Serial Differential Output 5 (+) |
| pci_exp_txn5 | O | PCI Express Transmit Negative: Serial Differential Output 5 (–) | |
| pci_exp_rxp5 | I | PCI Express Receive Positive: Serial Differential Input 5 (+) | |
| pci_exp_rxn5 | I | PCI Express Receive Negative: Serial Differential Input 5 (–) | |
| 6 | pci_exp_txp6 | O | PCI Express Transmit Positive: Serial Differential Output 6 (+) |
| pci_exp_txn6 | O | PCI Express Transmit Negative: Serial Differential Output 6 (–) | |
| pci_exp_rxp6 | I | PCI Express Receive Positive: Serial Differential Input 6 (+) | |
| pci_exp_rxn6 | I | PCI Express Receive Negative: Serial Differential Input 6 (–) | |
| 7 | pci_exp_txp7 | O | PCI Express Transmit Positive: Serial Differential Output 7 (+) |
| pci_exp_txn7 | O | PCI Express Transmit Negative: Serial Differential Output 7 (–) | |
| pci_exp_rxp7 | I | PCI Express Receive Positive: Serial Differential Input 7 (+) | |
| pci_exp_rxn7 | I | PCI Express Receive Negative: Serial Differential Input 7 (–) | |
| 8 | pci_exp_txp8 | O | PCI Express Transmit Positive: Serial Differential Output 8 (+) |
| pci_exp_txn8 | O | PCI Express Transmit Negative: Serial Differential Output 8 (–) | |
| pci_exp_rxp8 | I | PCI Express Receive Positive: Serial Differential Input 8 (+) | |
| pci_exp_rxn8 | I | PCI Express Receive Negative: Serial Differential Input 8 (–) | |
| 9 | pci_exp_txp9 | O | PCI Express Transmit Positive: Serial Differential Output 9 (+) |
| pci_exp_txn9 | O | PCI Express Transmit Negative: Serial Differential Output 9 (–) | |
| pci_exp_rxp9 | I | PCI Express Receive Positive: Serial Differential Input 9 (+) | |
| pci_exp_rxn9 | I | PCI Express Receive Negative: Serial Differential Input 9 (–) | |
| 10 | pci_exp_txp10 | O | PCI Express Transmit Positive: Serial Differential Output 10 (+) |
| pci_exp_txn10 | O | PCI Express Transmit Negative: Serial Differential Output 10 (–) | |
| pci_exp_rxp10 | I | PCI Express Receive Positive: Serial Differential Input 10 (+) | |
| pci_exp_rxn10 | I | PCI Express Receive Negative: Serial Differential Input 10 (–) | |
| 11 | pci_exp_txp11 | O | PCI Express Transmit Positive: Serial Differential Output 11 (+) |
| pci_exp_txn11 | O | PCI Express Transmit Negative: Serial Differential Output 11 (–) | |
| pci_exp_rxp11 | I | PCI Express Receive Positive: Serial Differential Input 11 (+) | |
| pci_exp_rxn11 | I | PCI Express Receive Negative: Serial Differential Input 11 (–) | |
| 12 | pci_exp_txp12 | O | PCI Express Transmit Positive: Serial Differential Output 12 (+) |
| pci_exp_txn12 | O | PCI Express Transmit Negative: Serial Differential Output 12 (–) | |
| pci_exp_rxp12 | I | PCI Express Receive Positive: Serial Differential Input 12 (+) | |
| pci_exp_rxn12 | I | PCI Express Receive Negative: Serial Differential Input 12 (–) | |
| 13 | pci_exp_txp13 | O | PCI Express Transmit Positive: Serial Differential Output 13 (+) |
| pci_exp_txn13 | O | PCI Express Transmit Negative: Serial Differential Output 13 (–) | |
| pci_exp_rxp13 | I | PCI Express Receive Positive: Serial Differential Input 13 (+) | |
| pci_exp_rxn13 | I | PCI Express Receive Negative: Serial Differential Input 13 (–) | |
| 14 | pci_exp_txp14 | O | PCI Express Transmit Positive: Serial Differential Output 14 (+) |
| pci_exp_txn14 | O | PCI Express Transmit Negative: Serial Differential Output 14 (–) | |
| pci_exp_rxp14 | I | PCI Express Receive Positive: Serial Differential Input 14 (+) | |
| pci_exp_rxn14 | I | PCI Express Receive Negative: Serial Differential Input 14 (–) | |
| 15 | pci_exp_txp15 | O | PCI Express Transmit Positive: Serial Differential Output 15 (+) |
| pci_exp_txn15 | O | PCI Express Transmit Negative: Serial Differential Output 15 (–) | |
| pci_exp_rxp15 | I | PCI Express Receive Positive: Serial Differential Input 15 (+) | |
| pci_exp_rxn15 | I | PCI Express Receive Negative: Serial Differential Input 15 (–) | |