6. 10M-10GbE MAC with IEEE 1588v2 Design Example
9. Interface Signals
9.0.10. IEEE 1588v2 Interface Signals
9.0.10.4. Timing Diagrams—IEEE 1588v2 Timestamp
The following timing diagrams show the timestamp of frames observed on the TX path for the IEEE 1588v2 feature.
Figure 9–9 shows the TX timestamp signals for the IEEE 1588v2 feature in a one step operation.
Figure 9–9. Egress Timestamp Insert for IEEE 1588v2 PTP Packet Encapsulated in IEEE 802.3 Egress Timestamp Insert, IEEE 1588v2, PTP Packet
2-step Timestamp Request,Input tx_egress_timestamp_request_valid tx_egress_timestamp_request_data[N:0]
2-step Timestamp Return,Output tx_egress_timestamp_96b_valid tx_egress_timestamp_96b_fingerprint[N:0]
tx_egress_timestamp_96b_data[95:0]
tx_egress_timestamp_64b_valid tx_egress_timestamp_64b_fingerprint[N:0]
tx_egress_timestamp_64b_data[63:0]
1-step Timestamp Insert,Input tx_etstamp_ins_ctrl_timestamp_insert tx_etstamp_ins_ctrl_timestamp_format 1-step Residence Time Update,Input tx_etstamp_ins_ctrl_residence_time_update tx_etstamp_ins_ctrl_ingress_timestamp_96b[95:0]
tx_etstamp_ins_ctrl_ingress_timestamp_64b[63:0]
tx_etstamp_ins_ctrl_residence_time_calc_format 1-step IPv4 and IPv6 Checksum,Input tx_etstamp_ins_ctrl_checksum_zero tx_etstamp_ins_ctrl_checksum_correct 1-step Location Offset,Input
tx_etstamp_ins_ctrl_offset_timestamp[15:0] Offset 1 Don’t-care
Don’t-care Don’t-care
Don’t-care Don’t-care
Don’t-care Don’t-care Don’t-care
Don’t-care Don’t-care tx_etstamp_ins_ctrl_offset_correction_field[15:0] Offset 2 tx_etstamp_ins_ctrl_offset_checksum_field[15:0]
tx_etstamp_ins_ctrl_offset_checksum_correction[15:0]
9–28 Chapter 9: Interface Signals
Figure 9–10 shows the TX timestamp signals for the first type of egress correction field update, where the residence time is calculated by subtracting 96 bit ingress timestamp from 96 bit egress timestamp. The result is updated in the correction field of the PTP frame encapsulated over UDP/IPv4.
Figure 9–10. Type 1 Egress Correction Field Update
Type 1 Egress Correction Field Update, 96b, IPV4
2-step Timestamp Request,Input tx_egress_timestamp_request_valid tx_egress_timestamp_request_data[N:0]
2-step Timestamp Return,Output tx_egress_timestamp_96b_valid tx_egress_timestamp_96b_fingerprint[N:0]
tx_egress_timestamp_96b_data[95:0]
tx_egress_timestamp_64b_valid tx_egress_timestamp_64b_fingerprint[N:0]
tx_egress_timestamp_64b_data[63:0]
1-step Timestamp Insert,Input tx_etstamp_ins_ctrl_timestamp_insert tx_etstamp_ins_ctrl_timestamp_format 1-step Residence Time Update,Input tx_etstamp_ins_ctrl_residence_time_update tx_etstamp_ins_ctrl_ingress_timestamp_96b[95:0]
tx_etstamp_ins_ctrl_ingress_timestamp_64b[63:0]
tx_etstamp_ins_ctrl_residence_time_calc_format 1-step IPv4 and IPv6 Checksum,Input tx_etstamp_ins_ctrl_checksum_zero tx_etstamp_ins_ctrl_checksum_correct 1-step Location Offset,Input tx_etstamp_ins_ctrl_offset_timestamp[15:0]
Offset 1 tx_etstamp_ins_ctrl_offset_correction_field[15:0]
Offset 2 tx_etstamp_ins_ctrl_offset_checksum_field[15:0]
tx_etstamp_ins_ctrl_offset_checksum_correction[15:0]
Ingress Timestamp Don’t-care
Don’t-care Don’t-care
Don’t-care Don’t-care
Don’t-care
Don’t-care
Don’t-care
Don’t-care
Chapter 9: Interface Signals 9–29
Figure 9–11 shows the TX timestamp signals for the second type of egress correction field update, where the 64 bit ingress timestamp has been pre-subtracted from the correction field at the ingress port. At the egress port, the 64 bit egress timestamp is added into the correction field and the correct residence time is updated in the correction field. This is the example of PTP frame encapsulated over UPD/IPV6.
Figure 9–11. Type 2 Egress Correction Field Update
Type 2 Egress Correction Field Update, 64b, IPV6
2-step Timestamp Request,Input tx_egress_timestamp_request_valid tx_egress_timestamp_request_data[N:0]
2-step Timestamp Return,Output tx_egress_timestamp_96b_valid tx_egress_timestamp_96b_fingerprint[N:0]
tx_egress_timestamp_96b_data[95:0]
tx_egress_timestamp_64b_valid tx_egress_timestamp_64b_fingerprint[N:0]
tx_egress_timestamp_64b_data[63:0]
1-step Timestamp Insert,Input tx_etstamp_ins_ctrl_timestamp_insert tx_etstamp_ins_ctrl_timestamp_format 1-step Residence Time Update,Input tx_etstamp_ins_ctrl_residence_time_update tx_etstamp_ins_ctrl_ingress_timestamp_96b[95:0]
tx_etstamp_ins_ctrl_ingress_timestamp_64b[63:0]
tx_etstamp_ins_ctrl_residence_time_calc_format 1-step IPv4 and IPv6 Checksum,Input tx_etstamp_ins_ctrl_checksum_zero tx_etstamp_ins_ctrl_checksum_correct 1-step Location Offset,Input tx_etstamp_ins_ctrl_offset_timestamp[15:0]
Offset 1 tx_etstamp_ins_ctrl_offset_correction_field[15:0]
Offset 2 tx_etstamp_ins_ctrl_offset_checksum_field[15:0]
tx_etstamp_ins_ctrl_offset_checksum_correction[15:0]
64’b0 Don’t-care
Don’t-care Don’t-care
Don’t-care Don’t-care
Don’t-care
Don’t-care
Don’t-care
Don’t-care
9–30 Chapter 9: Interface Signals
Figure 9–12 shows the TX timestamp signals for the IEEE 1588v2 feature in a two-step operation.
Figure 9–12. Egress Two-Step Operation
Egress Two-Step Operation, IEEE 1588v2, PTP Packet
2-step Timestamp Request,Input tx_egress_timestamp_request_valid tx_egress_timestamp_request_data[N:0]
2-step Timestamp Return,Output tx_egress_timestamp_96b_valid tx_egress_timestamp_96b_fingerprint[N:0]
tx_egress_timestamp_96b_data[95:0]
tx_egress_timestamp_64b_valid tx_egress_timestamp_64b_fingerprint[N:0]
tx_egress_timestamp_64b_data[63:0]
1-step Timestamp Insert,Input tx_etstamp_ins_ctrl_timestamp_insert tx_etstamp_ins_ctrl_timestamp_format 1-step Residence Time Update,Input tx_etstamp_ins_ctrl_residence_time_update tx_etstamp_ins_ctrl_ingress_timestamp_96b[95:0]
tx_etstamp_ins_ctrl_ingress_timestamp_64b[63:0]
tx_etstamp_ins_ctrl_residence_time_calc_format 1-step IPv4 and IPv6 Checksum,Input tx_etstamp_ins_ctrl_checksum_zero tx_etstamp_ins_ctrl_checksum_correct 1-step Location Offset,Input tx_etstamp_ins_ctrl_offset_timestamp[15:0]
tx_etstamp_ins_ctrl_offset_correction_field[15:0]
tx_etstamp_ins_ctrl_offset_checksum_field[15:0]
tx_etstamp_ins_ctrl_offset_checksum_correction[15:0]
Fingerprint
Fingerprint 96b Egress Timestamp
Fingerprint 64b Egress Timestamp
Don’t-care
Don’t-care Don’t-care Don’t-care
Don’t-care Don’t-care
Don’t-care Don’t-care Don’t-care Don’t-care
Don’t-care
Don’t-care Don’t-care Don’t-care
Don’t-care Don’t-care
Don’t-care Don’t-care Don’t-care Don’t-care