High accuracy timestamping of transmissions at physical layer of communication devices and systems
A method can include obtaining, at a physical communication layer integrated with a communication interface, a data packet, detecting, by a detection circuit integrated with the physical communication layer, a portion of data in the data packet corresponding to a marker identifying the data packet, linking, by the physical communication layer based on the marker, a timestamp with the data packet, and transmitting, by the physical communication layer, the data packet linked with the timestamp.
1. A method, comprising:
obtaining, at a physical communication layer integrated with a communication interface, a data packet;
detecting, by a detection circuit integrated with the physical communication layer, a portion of data in the data packet corresponding to a marker identifying the data packet;
linking, by the physical communication layer and based on the marker, a timestamp with the data packet; and
transmitting, by the physical communication layer, the data packet linked with the timestamp,
wherein detecting is performed on the data packet in processing included in the physical communication layer before processing of the data packet by a control layer of the communication interface in a receive stack or after processing of the data packet by the control layer of the communication interface in a transmit stack.
2. The method of claim 1 , further comprising:
linking, by the physical communication layer in response to detecting an interrupt, the timestamp with the data packet.
3. The method of claim 2 , further comprising:
triggering, by the physical communication layer in response to the detecting the marker, the interrupt.
4. The method of claim 1 , further comprising:
transmitting, by the physical communication layer, the data packet linked with the timestamp to a logical communication layer integrated with the communication interface.
5. The method of claim 1 , further comprising:
transmitting, by the physical communication layer, the data packet linked with the timestamp to a second physical communication layer integrated with a second communication interface operatively coupled with and external to the communication interface.
6. The method of claim 1 , further comprising:
obtaining the data packet from a logical communication layer integrated with the communication interface in accordance with a transmit operation of the communication interface.
7. The method of claim 1 , further comprising:
obtaining the data packet from a second physical communication layer integrated with a second communication interface in accordance with a receive operation of the communication interface.
8. The method of claim 1 , the communication interface comprising an Ethernet stack, and the physical communication layer comprising a physical medium attachment (PMA) layer of the Ethernet stack.
9. The method of claim 1 , the marker comprising a start frame delimiter (SFD), and the detection circuit configured to detect the SFD.
10. The method of claim 9 , further comprising:
splitting, by a logical communication layer integrated with the communication interface in response to a determination that the SFD corresponds to a particular type, the SFD into a first block and a second block; and
detecting, by the detection circuit, the first block to identify the marker.
11. A device, comprising:
a physical communication layer integrated with a communication interface, the physical communication layer configured to obtain a data packet, link a timestamp with the data packet and based on a marker identifying the data packet, and transmit the data packet linked with the timestamp; and
a detection circuit integrated with the physical communication layer, the detection circuit configured to detect a portion of data in the data packet corresponding to the marker,
wherein detecting is performed on the data packet in processing included in the physical communication layer before processing of the data packet by a control layer of the communication interface in a receive stack or after processing of the data packet by the control layer of the communication interface in a transmit stack.
12. The device of claim 11 , further comprising:
the physical communication layer configured to trigger an interrupt in response to the detecting the marker, and to link the timestamp with the data packet in response to detecting the interrupt.
13. The device of claim 11 , further comprising:
the physical communication layer configured to transmit the data packet linked with the timestamp to one or more of a logical communication layer integrated with the communication interface, and a second communication interface operatively coupled with and external to the communication interface.
14. The device of claim 11 , further comprising:
the physical communication layer configured to obtain the data packet from one or more of a logical communication layer integrated with the communication interface in accordance with a transmit operation of the communication interface, and a second physical communication layer integrated with a second communication interface in accordance with a receive operation of the communication interface.
15. The device of claim 11 , the communication interface comprising an Ethernet stack, and the physical communication layer comprising a physical medium attachment (PMA) layer of the Ethernet stack.
16. The device of claim 11 , the marker comprising a start frame delimiter (SFD), and the detection circuit configured to detect the SFD.
17. The device of claim 16 , further comprising:
a physical coding sublayer (PCS) integrated with the communication interface, the PCS configured to split the SFD into a first block and a second block in response to a determination that the SFD corresponds to a particular type; and
the detection circuit configured to detect the first block to identify the marker.
18. A system, comprising:
a physical communication layer integrated with a communication interface, the physical communication layer configured to obtain a data packet, link a timestamp with the data packet based on a marker identifying the data packet, and transmit the data packet linked with the timestamp; and
a detection circuit integrated with the physical communication layer, the detection circuit configured to detect a portion of data in the data packet corresponding to the marker,
wherein detecting is performed on the data packet in processing included in the physical communication layer before processing of the data packet by a control layer of the communication interface in a receive stack or after processing of the data packet by the control layer of the communication interface in a transmit stack.
19. The system of claim 18 , the communication interface comprising an Ethernet stack, and the physical communication layer comprising a physical medium attachment (PMA) layer of the Ethernet stack.