Device-to-device link training
Examples described herein relate to a network interface comprising physical medium dependent (PMD) circuitry, the PMD circuitry to during link training of at least one lane consistent with IEEE 802.3, exit to TIME_OUT state during TRAIN_LOCAL state based on consideration of expiration of a wait timer, loss of local_tf_lock state, and loss of remote_tf_lock state. In some examples, during link training for at least one lane consistent with IEEE 802.3, the PMD circuitry is to exit to TIME_OUT state during TRAIN_REMOTE state based on consideration of expiration of a wait timer, loss of local_tf_lock state, and loss of remote_tf_lock state. In some examples, link training consistent with IEEE 802.3 comprises performance of the PMD control function in Section 162.8.11 of IEEE 802.3ck.
1. An apparatus comprising:
a network interface device comprising:
a media access control (MAC) circuitry;
a direct memory access (DMA) circuitry; and
a physical layer interface (PHY) comprising:
circuitry to:
during link training of at least one lane with a remote link partner:
change from a TRAIN_LOCAL state to a TIMEOUT state based at least on expiration of a wait time,
enter a state based at least on loss of local_tf_lock state or loss of remote_tf_lock state, and
exit from the TIMEOUT state to a TRAINING_FAILED state based at least on a holdoff_timer_done state.
2. The apparatus of claim 1 , comprising:
circuitry to provide multiple transmit lanes;
analog equalizer circuitry associated with the multiple transmit lanes; and
a single microcontroller to control settings of the analog equalizer circuitry for the multiple transmit lanes based on the link training.
3. The apparatus of claim 1 , comprising:
circuitry to provide multiple receive lanes;
analog equalizer circuitry associated with the multiple receive lanes; and
a single microcontroller to control settings of the analog equalizer circuitry for the multiple receive lanes based on the link training.
4. The apparatus of claim 1 , wherein the local_tf_lock state comprises indication of successful decoding of training frames.
5. The apparatus of claim 1 , wherein the remote_tf_lock state comprises indication of successful decoding of training frames by the remote link partner.
6. The apparatus of claim 1 , wherein the circuitry is to:
receive communication of loss of remote_tf_lock state via an out-of-band communication.
7. The apparatus of claim 1 , wherein the circuitry is to:
receive communication of loss of remote_tf_lock state by a read of a register of the remote link partner.
8. The apparatus of claim 1 , wherein the link training is to commence based on connection of a cable.
9. The apparatus of claim 1 , wherein lane rates comprise 50 Gbps or 100 Gbps.
10. The apparatus of claim 1 , wherein at least one packet transmitted to the remote link partner is consistent with Ethernet.
11. An apparatus comprising:
a switch comprising:
circuitry to:
during link training of at least one lane with a remote link partner:
change from a TRAIN_LOCAL state to a TIMEOUT state based at least on expiration of a wait time,
enter a state based at least on loss of local_tf_lock state or loss of remote_tf_lock state, and
exit from the TIMEOUT state to a TRAINING_FAILED state based at least on a holdoff_timer_done state.
12. The apparatus of claim 11 , comprising:
circuitry to provide multiple transmit lanes;
analog equalizer circuitry associated with the multiple transmit lanes; and
a single microcontroller to control settings of the analog equalizer circuitry for the multiple transmit lanes based on the link training.
13. The apparatus of claim 11 , comprising:
circuitry to provide multiple receive lanes;
analog equalizer circuitry associated with the multiple receive lanes; and
a single microcontroller to control settings of the analog equalizer circuitry for the multiple receive lanes based on the link training.
14. The apparatus of claim 11 , wherein the local_tf_lock state comprises indication of successful decoding of training frames.
15. The apparatus of claim 11 , wherein the remote_tf_lock state comprises indication of successful decoding of training frames by the remote link partner.
16. The apparatus of claim 11 , wherein the circuitry is to:
receive communication of loss of remote_tf_lock state via an out-of-band communication.
17. The apparatus of claim 11 , wherein the circuitry is to:
receive communication of loss of remote_tf_lock state by a read of a register of the remote link partner.
18. The apparatus of claim 11 , wherein the link training is to commence based on connection of a cable.
19. The apparatus of claim 11 , wherein lane rates comprise 50 Gbps or 100 Gbps.
20. The apparatus of claim 11 , wherein at least one packet transmitted to the remote link partner is consistent with Ethernet.
21. An apparatus comprising:
Ethernet physical layer transceiver (PHY) circuitry for use in frame communication with a remote link partner, the Ethernet PHY circuitry comprising:
circuitry to:
during link training of at least one lane with a remote link partner:
change from a TRAIN_LOCAL state to a TIMEOUT state based at least on expiration of a wait time,
enter a state based at least on loss of local_tf_lock state or loss of remote_tf_lock state, and
exit from the TIMEOUT state to a TRAINING_FAILED state based at least on a holdoff_timer_done state.
22. The apparatus of claim 21 , comprising:
circuitry to provide multiple transmit lanes;
analog equalizer circuitry associated with the multiple transmit lanes; and
a single microcontroller to control settings of the analog equalizer circuitry for the multiple transmit lanes based on the link training.
23. The apparatus of claim 21 , comprising:
circuitry to provide multiple receive lanes;
analog equalizer circuitry associated with the multiple receive lanes; and
a single microcontroller to control settings of the analog equalizer circuitry for the multiple receive lanes based on the link training.
24. The apparatus of claim 21 , wherein the local_tf_lock state comprises indication of successful decoding of training frames.
25. The apparatus of claim 21 , wherein the remote_tf_lock state comprises indication of successful decoding of training frames by the remote link partner.
26. The apparatus of claim 21 , wherein the circuitry is to:
receive communication of loss of remote_tf_lock state via an out-of-band communication.
27. The apparatus of claim 21 , wherein the circuitry is to:
receive communication of loss of remote_tf_lock state by a read of a register of the remote link partner.
28. The apparatus of claim 21 , wherein the link training is to commence based on connection of a cable.
29. The apparatus of claim 21 , wherein lane rates comprise 50 Gbps or 100 Gbps.
30. The apparatus of claim 21 , wherein at least one packet transmitted to the remote link partner is consistent with Ethernet.