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7.13.2. TX 2-Step Timestamp Interface
The timestamp interface signals are valid when i_tx_valid and i_tx_startofpacket signals are high. To initiate a timestamp request, the i_ptp_ts_req signal must be high. You also must specify a fingerprint value in the i_ptp_fp signal. The fingerprint values are re-usable once the IP core returns a packet with the timestamp.
When the IP core returns the timestamp for a packet with a 2-step timestamp request, it asserts the o_ptp_ets_valid signal to indicate that the o_ptp_ets and o_ptp_ets_fp signals contain the timestamp information. The o_ptp_ets contains the timestamp and the o_ptp_ets_fp signal indicates the specific packet the timestamp is for. The IP processes the timestamp requests in the order they were received.
|   Signal Name  |  
       Width |   Description  |  
      
|---|---|---|
|   i_ptp_ts_req i_ptp_ts_req[1:0]  |  
         1 bit (10GE/25GE/50GE/100GE/200GE) 2 bits (400GE)  |  
       Request a 2-step timestamp signal for the current TX packet when Ethernet rate is 10GE/25GE/50GE/100GE/200GE/400GE. 
        
  |  
      
|  i_ptp_fp[w],  where w represents timestamp fingerprint width i_ptp_fp[w*2], where w is 8-12  |  
         w bit (10GE/25GE/50GE/100GE/200GE) (w*2) bits (400GE)  |  
       Fingerprint signal for current TX packet when Ethernet rate is 10GE/ 25GE/50GE/100GE/200GE/400GE.  Assigns an 8 bit fingerprint to a TX packet that is being transmitted so the returned TX egress timestamp can be identified with respective TX packet. 
 Used for both 2-step and 1-step PTP packets. Intel recommends to use large range of fingerprints to avoid assigning same fingerprint to two currently processed TX packets.  |  
      
|   o_ptp_ets_valid o_ptp_ets_valid[1:0]  |  
         1 bit (10GE/25GE/50GE/100GE/200GE) 2 bits (400GE)  |  
       TX egress timestamp valid signal when Ethernet rate is 10GE/ 25GE/50GE/100GE/200GE/400GE. | 
|   o_ptp_ets[95:0] o_ptp_ets[191:0]  |  
         96 bits (10GE/25GE/50GE/100GE/200GE 192 bits (400GE)  |  
       TX egress timestamp bus when Ethernet rate is 10GE/ 25GE/50GE/100GE/200GE/400GE. 
         
         The bus presents an egress timestamp for the TX packet transmitted with the fingerprint given by o_ptp_ets_fp signal. 
           
 The egress timestamp applies for 2-step and 1-step PTP packets.  |  
      
|   o_ptp_ets_fp[w] o_ptp_ets_fp[w*2], where w is 8-12  |  
         w bits (10GE/25GE/50GE/100GE/200GE) (w*2) bits (400GE)  |  
       TX egress timestamp fingerprint when Ethernet rate is 10GE/25GE/ 50GE/100GE/200GE/400GE. 
         
         The bus presents the fingerprint for the current 2-step egress timestamp. You use the fingerprint to determine which TX packet the timestamp belongs to. 
           
 The egress timestamp applies for 2-step and 1-step PTP packets.  |