# US 10,374,737 B2 · Systems for selecting a time reference > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,374,737 B2 - Document ID: US10374737B2 - Status: Granted - Kind: B2 - Application number: 15/728,306 - Filed: 2017-10-09 - Published: 2018-02-01 - Granted: 2019-08-06 - Earliest claimed: 2014-09-09 - Assignees: Endace Technology Limited - Applicants: Endace Technology Limited - Inventors: David Earl; Stuart Wilson - Web page: https://patentgrep.com/patent/US10374737B2 ## CPC - H04J 3/0697: {Synchronisation in a packet node} - G06F 13/4068: {Electrical coupling} - H04L 12/10: Current supply arrangements - G06F 21/34: involving the use of external additional devices, e.g. dongles or smart cards - H04L 63/0876: {based on the identity of the terminal or configuration, e.g. MAC address, hardware or software configuration or device fingerprint} - H04L 63/123: {received data contents, e.g. message integrity} - H04J: MULTIPLEX COMMUNICATION (transmission in general H04B; peculiar to transmission of digital information H04L5/00; systems for the simultaneous or sequential transmission of more than one television signal H04N7/08; in exchanges H04Q11/00; stereophonic systems H04S) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A small form-factor pluggable (SFP) time signal adapter module includes a printed circuit board, a cable connector mounted to the printed circuit board, and a differential receiver coupled to the cable connector, one or more of the plurality of wire traces, and an SFP edge connector. The printed circuit board has a plurality of wire traces and a plurality of pads of the SFP edge connector is at least coupled to two of the plurality of wire traces. The cable connector is coupled to at least one or more of the plurality of wire traces. The cable connector couples to a connector of a cable to receive a differential time reference signal. The differential receiver receives and differentiates the differential time input signal to generate a single ended time reference signal that is coupled to a pad of the SFP edge connector. ## Claims ### Claim 1 A network server comprising: a mother board with a processor, a memory, and a plurality of sockets; a plurality of network coprocessing cards coupled to the plurality of sockets of the mother board, each of the plurality of network coprocessing cards having a coprocessor, a plurality of small form-factor pluggable (SFP) data ports in communication with the coprocessor, and a time signal port in communication with the coprocessor; and a plurality of SFP time signal adapter modules coupled into each time signal port of each of the plurality of network coprocessing cards to receive a time reference signal into the plurality of network coprocessing cards. ### Claim 2 (depends on 1) The network server of claim 1, wherein each of the plurality of network coprocessing cards further includes: a printed circuit board (PCB); and a peripheral component interconnect express (PCIe) connector mounted to the printed circuit board and coupled to the coprocessor. ### Claim 3 (depends on 2) The network server of claim 2, wherein each of the plurality of network coprocessing cards further includes: a buffer memory coupled to the coprocessor. ### Claim 4 A packet processing circuit for processing data packets, the packet processing circuit comprising: time signal selection logic including a plurality of multiplexers coupled together to receive a plurality of time reference signals into a plurality of input terminals and select one time reference signal on an output terminal, wherein at least one of the plurality of time reference signals is an external time reference signal from an external time reference generator coupled to one input terminal of the plurality of input terminals; and a configuration register coupled to the plurality of multiplexers, the configuration register to receive and store bits to generate a plurality of selection signals coupled to a plurality of select input terminals of the plurality of multiplexers to select the one time reference signal on the output terminal. ### Claim 5 (depends on 4) The packet processing circuit of claim 4, wherein the plurality of multiplexers comprises a first multiplexer having input terminals receiving a first time reference signal and a first external time reference signal; a second multiplexer having input terminals receiving a third time reference signal and a fourth time reference signal; and a third multiplexer having inputs coupled to outputs of the first multiplexer and the second multiplexer to receive a subset of the plurality of time reference signals, wherein the first, second, and third multiplexers receive the plurality of selection signals to select the one time reference signal on the output terminal of the third multiplexer. ### Claim 6 (depends on 5) The packet processing circuit of claim 5, wherein at least one of the first, second, third, and fourth time reference signals is a second external time reference signal. ### Claim 7 (depends on 5) The packet processing circuit of claim 5, wherein at least one of the first, second, third, and fourth time reference signals is a backward compatible time reference signal can be selected in the case of a replacement printed circuit card for pre-existing networking equipment. ### Claim 8 (depends on 5) The packet processing circuit of claim 5, wherein at least one of the first, second, third, and fourth time reference signals is an internal time reference signal. ### Claim 9 (depends on 8) The packet processing circuit of claim 8, wherein at least one of the first, second, third, and fourth time reference signals is a high resolution internal time reference signal, the high resolution internal time reference signal is a forward compatible time reference signal that can be selected in the case of new networking equipment. ### Claim 10 (depends on 5) The packet processing circuit of claim 5, wherein the first time reference signal is a universal internal time reference signal, the second time reference signal is an external time reference signal; the third time reference signal is a card specific internal time reference signal; and the fourth time reference signal is a high resolution internal time reference signal. ### Claim 11 (depends on 5) The packet processing circuit of claim 5, wherein the selected one time reference signal on the output terminal has a rate of one or more pulses per second. ### Claim 12 (depends on 5) The packet processing circuit of claim 5, wherein the selected one time reference signal on the output terminal has a rate of less than one pulse per second. ### Claim 13 (depends on 4) The packet processing circuit of claim 4, wherein at least another one of the plurality of time reference signals is an internal time reference signal. ### Claim 14 A system comprising: a router to receive and transmit data packets plurality of multiplexers coupled together to receive a plurality of time reference a switch coupled to the router, a time reference generator coupled to the router; a plurality coprocessing cards coupled in communication with the switch and the time reference generator; a plurality of small form pluggable time modules coupled to the plurality coprocessing cards; wherein the switch receives data signal packets, reads IP addresses, and routes the data signal packets to the plurality coprocessing cards; and wherein the time reference generator generates an external time reference signal communicated to each of the plurality of small form pluggable time modules. ### Claim 15 (depends on 14) The system of claim 14, wherein the switch routes copies of data signal packets in a load balanced manner to each of the plurality of coprocessing cards. ### Claim 16 (depends on 14) The system of claim 14, wherein the plurality of small form pluggable time modules are further coupled to the switch to receive time signal packets from the time reference generator. ### Claim 17 (depends on 16) The system of claim 16, wherein each of the plurality of small form pluggable time modules are electro-optical small form pluggable time modules, and the system further comprises a plurality of optical cables coupled to and between the switch and the plurality of electro-optical small form pluggable time modules. ### Claim 18 (depends on 16) The system of claim 16, wherein each of the plurality of small form pluggable time modules are electrical small form pluggable time modules, and the system further comprises a plurality of wired Ethernet cables coupled to and between the switch and the plurality of electrical small form pluggable time modules. ### Claim 19 (depends on 14) The system of claim 14, further comprising: a splitter coupled to the time reference generator to split a time reference signal from the time reference generator into a plurality of time reference signals; wherein the plurality of small form pluggable time modules are further coupled to the splitter to receive the plurality of time reference signals. ### Claim 20 (depends on 19) The system of claim 19, wherein each of the plurality of small form pluggable time modules are electrical small form pluggable time modules, and the system further comprises a plurality of wired Ethernet cables coupled to and between the switch and the plurality of electrical small form pluggable time modules.