In-band lane alignment for a multi-lane transceiver
View Patent ↗Methods, systems, and apparatuses are described for aligning lanes of low speed serial links coupled to a transceiver. The transceiver cooperatively performs lane alignment operations with a low speed device during initialization of the transceiver and the low speed device. The lane alignment operations are performed in-band using the low speed serial links, and therefore, do not require additional out-of-band-signaling wires between the transceiver and the low speed device to perform the lane alignment operations. The lane alignment operations may be performed by a handshaking process performed by the transceiver and the low speed device, where the transceiver and the low speed device provide training pattern(s) of data that are used to align the low speed serial links. The low speed serial links are continuously monitored after initialization is complete to detect various transient impairments and to re-initiate lane alignment operations in response to detecting such impairments.
1. A method, comprising:
transmitting a first instance of a first training pattern of data over a plurality of first lanes by a lane alignment master of a first device to a lane alignment slave of a second device;
receiving a first indication from a lane alignment slave of the first device that is configured to perform a lane alignment operation on a plurality of second lanes using a second instance of the first training pattern of data received from a lane alignment master of the second device over the plurality of second lanes, the first indication indicating that the plurality of second lanes has been aligned;
transmitting a first instance of a second training pattern over the plurality of first lanes from the lane alignment master of the first device to the lane alignment slave of the second device in response to receiving the first indication; and
receiving a second indication from the lane alignment slave of the first device, the second indication indicating that the lane alignment slave of the first device has received a second instance of the second training pattern of data from the lane alignment master of the second device over the plurality of second lanes.
2. The method of claim 1 , wherein said transmitting a first instance of a first training pattern of data over a plurality of first lanes from a lane alignment master of the first device to a lane alignment slave of the second device comprises:
transmitting a first instance of an illegal data pattern over the plurality of first lanes from the lane alignment master of the first device to the lane alignment slave of the second device for a predetermined time period;
determining whether the predetermined time period has expired; and
transmitting the first instance of the first training pattern of the data over the plurality of first lanes from the lane alignment master of the first device to the lane alignment slave of the second device in response to determining that the predetermined time period has expired.
3. The method of claim 2 , wherein said transmitting a first instance of an illegal data pattern over the plurality of first lanes from the lane alignment master of the first device to the lane alignment slave of the second device for a predetermined time period comprises:
receiving a third indication from the lane alignment slave of the first device, the third indication indicating that a number of detected violations of an encoding scheme used to transmit data between the first device and the second device over the plurality of second lanes reached a predetermined threshold; and
transmitting the first instance of the illegal data pattern over the plurality of first lanes from the lane alignment master of the first device to the lane alignment slave of the second device for the predetermined time period in response to receiving the third indication from the lane alignment slave of the first device.
4. The method of claim 1 , further comprising:
transmitting a third instance of the second training pattern over the plurality of first lanes from the lane alignment master of the first device to the lane alignment slave of the second device a predetermined number of times in response to receiving the second indication from the lane alignment slave of the first device.
5. The method of claim 4 , further comprising:
determining that the third instance of the second training pattern has been transmitted a predetermined number of times;
transmitting a control signal from the lane alignment master of the first device to selection logic of the first device in response to determining that the third instance of the second training pattern has been transmitted a predetermined number of times, the control signal enabling the selection logic to provide data received over a high speed serial link to the second device over the plurality of first lanes.
6. The method of claim 1 , wherein the first training pattern of data and the second training pattern of data are different patterns of data.
7. A method, comprising:
receiving an instance of a first training pattern of data over a plurality of first lanes by a lane alignment slave of a first device from a lane alignment master of a second device;
performing a lane alignment operation on the plurality of first lanes using the instance of the first training pattern of data received from the lane alignment master of the second device;
determining whether the lane alignment operation has aligned the plurality of first lanes; and
transmitting a first indication from the lane alignment slave of the first device to the lane alignment master of the first device in response to determining that the lane alignment operation has aligned the plurality of first lanes.
8. The method of claim 7 , further comprising:
receiving an instance of a second training pattern of data over the plurality of first lanes by the lane alignment slave of the first device from the lane alignment master of the second device;
determining whether the instance of the second training pattern of data has been received a predetermined number of times; and
transmitting a second indication from the lane alignment slave of the first device to the lane alignment master of the first device in response to determining that the instance of the second training pattern of data has been received a predetermined number of times.
9. The method of claim 8 , further comprising:
transmitting data received over the plurality of first lanes to concentrator logic of the first device subsequent to transmitting the second indication from the lane alignment slave of the first device to the lane alignment master of the first device, wherein the concentrator logic is configured to serialize the data received over the plurality of first lanes for transmission over a high speed serial link.
10. The method of claim 7 , wherein the first training pattern of data and the second training pattern of data are the same patterns of data.
11. The method of claim 7 , wherein the first training pattern and the second training pattern are different patterns of data.
12. The method of claim 7 , further comprising:
monitoring the plurality of first lanes to determine whether the plurality of first lanes have lost alignment; and
transmitting a second indication to the lane alignment master of the first device in response to determining that the plurality of first lanes have lost alignment, wherein the second indication causes the lane alignment master of the first device to provide illegal data patterns to a lane alignment slave of the second device.
13. The method of claim 7 , further comprising:
monitoring the plurality of first lanes for illegal data patterns that cause violations of an encoding scheme used to transmit data between the first device and the second device over the plurality of first lanes;
determining whether a number of the violations reaches a predetermined threshold; and
transmitting a second indication to the lane alignment master of the first device in response to determining that the number of the violations reaches the predetermined threshold, wherein the second indication causes the lane alignment master of the first device to provide illegal data patterns to a lane alignment slave of the second device.
14. A lane alignment slave of a first device configured to align a plurality of first lanes, comprising:
a receiver interface coupled to the plurality of first lanes, the receiver interface configured to receive an instance of a first training pattern of data over the plurality of first lanes from a lane alignment master of a second device; and
a lane aligner configured to perform a lane alignment operation on the plurality of first lanes using the instance of the first training pattern of data received from the lane alignment master of the second device and to determine whether the lane alignment operation has aligned the plurality of first lanes,
wherein the lane aligner provides a first indication to a lane alignment master of the first device in response to a determination that the lane alignment operation has aligned the plurality of first lanes.
15. The lane alignment slave of the first device of claim 14 , wherein the receiver interface is further configured to:
receive an instance of a second training pattern of data over the plurality of first lanes from the lane alignment master of the second device;
determine whether the instance of the second training pattern of data has been received a predetermined number of times; and
provide a second indication to the lane alignment master of the first device in response to a determination that the instance of the second training pattern of data has been received a predetermined number of times.
16. The lane alignment slave of the first device of claim 15 , wherein the lane aligner is further configured to:
provide data received over the plurality of first lanes subsequent to transmitting the second indication to the lane alignment master of the first device to concentrator logic of the first device, wherein the concentrator logic is configured to serialize the data received over the plurality of first lanes for transmission over a high speed serial link.
17. The lane alignment slave of the first device of claim 14 , wherein the first training pattern of data and the second training pattern of data are the same patterns of data.
18. The lane alignment slave of the first device of claim 14 , wherein the first training pattern and the second training pattern are different patterns of data.
19. The lane alignment slave of the first device of claim 14 , wherein the lane aligner is further configured to:
monitor the plurality of first lanes to determine whether the plurality of first lanes have lost alignment; and
provide a second indication to the lane alignment master of the first device in response to a determination that the plurality of first lanes have lost alignment, wherein the second indication causes the lane alignment master of the first device to provide illegal data patterns to a lane alignment slave of the second device.
20. The lane alignment slave of the first device of claim 14 , wherein the lane aligner is further configured to:
monitor the plurality of first lanes for illegal data patterns that cause violations of an encoding scheme used to transmit data between the first device and the second device over the plurality of first lanes;
determine whether a number of the violations reaches a predetermined threshold; and
provide a second indication to the lane alignment master of the first device in response to a determination that the number of the violations reaches the predetermined threshold, and wherein the second indication causes the lane alignment master of the first device to provide illegal data patterns to a lane alignment slave of the second device.