Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W74/00—Wireless channel access
  • H04W74/08—Non-scheduled access, e.g. ALOHA
  • H04W74/0808—Non-scheduled access, e.g. ALOHA using carrier sensing, e.g. carrier sense multiple access [CSMA]
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L12/00—Data switching networks
  • H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
  • H04L12/40—Bus networks
  • H04L12/407—Bus networks with decentralised control
  • H04L12/413—Bus networks with decentralised control with random access, e.g. carrier-sense multiple-access with collision detection [CSMA-CD]
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L25/00—Baseband systems
  • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
  • H04L25/0264—Arrangements for coupling to transmission lines
  • H04L25/0272—Arrangements for coupling to multiple lines, e.g. for differential transmission
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W74/00—Wireless channel access
  • H04W74/08—Non-scheduled access, e.g. ALOHA
  • H04W74/0808—Non-scheduled access, e.g. ALOHA using carrier sensing, e.g. carrier sense multiple access [CSMA]
  • H04W74/0825—Non-scheduled access, e.g. ALOHA using carrier sensing, e.g. carrier sense multiple access [CSMA] with collision detection

Definitions

• the present disclosure relates generally to communication networks, and more specifically, to detecting collisions on a single pair Ethernet network.
• Ethernet communication generally refers to point-to-point communication within a network of multiple end points. Ethernet generally makes efficient use of shared resources, is easy to maintain and reconfigure, and is compatible across many systems.
• FIG. 1 depicts a network including a number of nodes, in accordance with various embodiments of the disclosure
• FIG. 2 illustrates a node, including a media access layer and a physical layer, coupled to a network, according to various embodiments of the disclosure
• FIGS. 3A and 3B depict timing diagrams showing various signals associated with a network, in accordance with various embodiments of the disclosure
• FIG. 4 shows another timing diagram illustrating various signals associated with a network, in accordance with various embodiments of the disclosure
• FIG. 5 illustrates an example physical layer of a node of a network, according to various embodiments of the disclosure
• FIG. 6 illustrates an example signal detector, according to various embodiments of the disclosure.
• FIG. 7 is a flowchart of an example method of operating a physical layer (PHY) of a network, according to various embodiments of the disclosure.
• PHY physical layer
• DSP Digital Signal Processor
• IC Integrated Circuit
• ASIC Application Specific Integrated Circuit
• FPGA Field Programmable Gate Array
• a general-purpose processor may also be referred to herein as a host processor or simply a host
• the processor may be any conventional processor, controller, microcontroller, or state machine.
• a processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.
• a general-purpose computer including a processor is considered a special-purpose computer while the general-purpose computer is configured to execute computing instructions (e.g., software code) related to embodiments of the present disclosure.
• the embodiments may be described in terms of a process that is depicted as a flowchart, a flow diagram, a structure diagram, or a block diagram. Although a flowchart may describe operational acts as a sequential process, many of these acts can be performed in another sequence, in parallel, or substantially concurrently. In addition, the order of the acts may be re-arranged.
• a process may correspond to a method, a thread, a function, a procedure, a subroutine, a subprogram, etc.
• the methods disclosed herein may be implemented in hardware, software, or both. If implemented in software, the functions may be stored or transmitted as one or more instructions or code on computer-readable media.
• Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another.
• any reference to an element herein using a designation such as “first,” “second,” and so forth does not limit the quantity or order of those elements, unless such limitation is explicitly stated. Rather, these designations may be used herein as a convenient method of distinguishing between two or more elements or instances of an element. Thus, a reference to first and second elements does not mean that only two elements may be employed there or that the first element must precede the second element in some manner.
• a set of elements may comprise one or more elements.
• the term “substantially” in reference to a given parameter, property, or condition means and includes to a degree that one of ordinary skill in the art would understand that the given parameter, property, or condition is met with a small degree of variance, such as, for example, within acceptable manufacturing tolerances.
• the parameter, property, or condition may be at least 90% met, at least 95% met, or even at least 99% met.
• a vehicle such as an automobile, a truck, a bus, a ship, and/or an aircraft, may include a vehicle communication network.
• the complexity of a vehicle communication network may vary depending on a number of electronic devices within the network.
• an advanced vehicle communication network may include various control modules for, for example, engine control, transmission control, safety control (e.g., antilock braking), and emissions control.
• engine control e.g., engine control
• transmission control e.g., transmission control
• safety control e.g., antilock braking
• emissions control e.g., antilock braking
• 10SPE (i.e., 10 Mbps Single Pair Ethernet) is network technology specification currently under development by the Institute of Electrical and Electronics Engineers as specification IEEE 802.3cgTM.
• a 10SPE network may include a number of nodes (also referred to herein as “endpoints”), wherein at least some of the nodes may include a 10SPE physical layer (PHY).
• a 10SPE PHY may operate in a half-duplex mode and may support carrier-sense multiple access with collision detection (CSMA/CD), which is a media access control method used most notably in early Ethernet technology for local area networking.
• CSMA/CD carrier-sense multiple access with collision detection
• a node that wishes to transmit via a bus should defer transmission if there is already a carrier on the bus. In other words, if a node senses a carrier on the bus, the node should wait to transmit.
• the inventors of this disclosure appreciate that the above assumes non-simultaneous transmission by nodes of the network, that is, assumes that there will be a sufficient gap in time between when nodes begin to transmit for a later in time node to detect the carrier for an earlier in time node’s data packet. However, the inventors of this disclosure appreciate that sometimes two or more nodes may begin to transmit so close in time that the nodes will not detect an active carrier before beginning to transmit.
• a PHY while transmitting, may be configured to observe signal levels at a 10SPE bus and to detect a collision on the bus based, at least in part, on the observed signal levels. Stated another way, a PHY, while transmitting, may determine whether at least one other node in a network is also transmitting.
• detection of an unusual signal amplitude may be indicative of a collision on a 10SPE network. More specifically, in some embodiments, a network collision may be detected when an amplitude of a signal observed on the bus by transmitting PHY is either larger or smaller than an expected amplitude. For example, a PHY, which is transmitting a first signal (a “locally transmitted signal”), may observe a second signal that may include the first signal and another signal (“remotely transmitted signal”) transmitted by another PHY.
• the signals will constructively interfere and the signal observed at the PHY should have an amplitude that is greater than an expected amplitude. If the locally transmitted signal has a different phase as the remotely transmitted signal, then, in theory, the signals will destructively interfere with each other and the signal observed at the PHY should have an amplitude that is less than an expected amplitude.
• a 10SPE PHY may include a signal detector, which may include, for example, an amplitude detector (e.g., an analog amplitude detector) and optional logic.
• the signal detector may be operably coupled to a bus and configured to respond to a signal at the bus that has an amplitude characteristic of a collision.
• the signal detector which may be used to detect collisions while a PHY is operating in a transmit mode, may also be used to detect signals while a PHY is operating in a receive mode.
• a signal detector of a PHY may be configured to use one or more threshold values.
• the signal detector may be configured to use a first “greater” threshold value.
• the signal detector may be programmed with the first threshold (e.g., a first differential threshold) during a first phase (e.g., for a first number of bits of a collision detection operation).
• the signal detector may be configured to use a second, lower threshold value (e.g., a second differential threshold).
• the lower threshold value may the same threshold value used for signal detection (e.g., during a receive mode).
• the signal detector may be programmed with the second threshold value during a second phase (e.g., for a second number of bits of a collision detection operation).
• an output of a signal detector may be multi-sampled (e.g., oversampled) to, for example, enhance reliability with high time domain resolution.
• the output of a signal detector may be sampled every 10 nanoseconds.
• a collision detection operation may be performed for a specified amount of time (e.g., beginning when signal transmission begins). More specifically, for example, a collision detection operation performed at a PHY may be initiated in response to the PHY transmitting a signal, and the collision detection operation may be performed for a specified bit time (e.g., a programmable bit time of N bits (e.g., 512 bits)) subsequent to initiating transmission.
• a specified amount of time may be, as non-limiting examples, in terms of time (e.g., microseconds, without limitation), bits/bytes, symbols, or clock cycles, without limitation.
• an amount of time may be specified in combinational logic or control bit values stored at a control register.
• a collision detection operation may be performed during data transmission (e.g., when transmit is enabled). In other embodiments, a collision detection operation may be limited to a specific amount of time may help to avoid collisions with future incoming signals. According to various embodiments, after expiration of a programmable bit time (e.g., 512 bits), the collision detection operation may be terminated (e.g., via failing to process and/or utilize a signal (e.g., an output of the signal detector) generated via the detection circuity.
• a programmable bit time e.g., 512 bits
• FIG. 1 is a block diagram of at least a portion of a network (e.g., a wired local area network) 100, according to some embodiments. More specifically, network 100 may include a 10SPE network. Network 100 includes a number of nodes (also referred to as “endpoints”) operably coupled to a communication bus 104. More specifically, network 100 includes nodes 102_1, 102_2, 102_3, 102_4, 102_5, and 102_6, generally nodes 102.
• network 100 is depicted as having six nodes, the disclosure is not so limited, and a network may include more than six nodes (e.g., eight nodes, ten nodes, twelve nodes, or more) or less than six nodes (e.g., five nodes, three nodes, or two nodes).
• Each node 102_1, 102_2, 102_3, 102_4, 102_5, and 102_6 is configured to communicate via communication bus 104, which may include or be a shared bus (e.g., a single twisted pair).
• shared bus refers to a wired transmission medium, such as a single twisted pair, that conducts both transmit signals and receive signals over the same conductive structure (e.g., one or more cables).
• network 100 may be used in an automotive environment. More specifically, by way of non-limiting example, network 100 may be configured to connect one or more of nodes 102 to other nodes, a computer, and/or controller (e.g., within a vehicle). In this example, each node 102 of network 100 may include, for example, an amplifier, a microphone, an antenna, a speaker, and/or a sensor, without limitation.
• Other non-limiting examples of application environments include lighting systems, residential and commercial building networks, and elevator networks.
• node 102 depicts an example network segment 101 including a node 102 (e.g., node 102_1, node 102_2, node 102_3, node 102_4, node 102_5, or node 102_6) coupled to communication bus 104.
• node 102 includes a physical layer (PHY) 106 operably coupled to a media access control (MAC) layer 108.
• PHY 106 may be configured to serve as an interface for a physical connection between MAC 108 and communication bus 104.
• PHY 106 includes at least a portion of Ethernet physical layer circuitry.
• a PHY (e.g., PHY 106) may include a transceiver having transmit circuitry and receive circuitry.
• FIGS. 3A and 3B depict timing diagrams showing various signals associated with a network (e.g., network 100 of FIG. 1), according to various embodiments of the disclosure. More specifically, FIG. 3A depicts a timing diagram 300 showing signals associated with detecting a collision based on a signal observed at a PHY, where the observed signal has an amplitude that is greater than expected. More specifically, timing diagram 300 includes a signal 302 indicative of signal transmitted by a first node (e.g., of node 102_1), and a signal 304 indicative of signal transmitted by a second node (e.g., of node 102_2).
• a first node e.g., of node 102_1
• a signal 304 indicative of signal transmitted by a second node
• Timing diagram 300 further includes a signal 306 indicative of signal observed by a PHY of the second node (e.g., of node 102_2). Also, timing diagram 300 further depicts threshold values 308A and 308B (i.e., for detecting a signal having an amplitude whose absolute value is greater than expected), and a signal 310, generated at a signal detector at the PHY, which may be indicative of a collision.
• a signal 306 indicative of signal observed by a PHY of the second node (e.g., of node 102_2).
• timing diagram 300 further depicts threshold values 308A and 308B (i.e., for detecting a signal having an amplitude whose absolute value is greater than expected), and a signal 310, generated at a signal detector at the PHY, which may be indicative of a collision.
• an amplitude of signal 306 which represents a signal observed at the PHY of the second node (e.g., of node 102_2), exceeds at least one of thresholds 308A and 308B, and in response signal 310 transitions from a low state to a high state to indicate a collision.
• the absolute value of the amplitude of signal 306 exceeds both thresholds 308A and 308B, the amplitude of signal 306 is greater than expected (i.e., compared to if only the second node was transmitting).
• FIG. 3A depicts a timing diagram 350 showing signals associated with detecting a collision based on a signal observed at a PHY having an amplitude that is less than expected.
• timing diagram 350 includes a signal 352 indicative of a signal transmitted by the first PHY (e.g., of node 102_1), and a signal 354 indicative of a signal transmitted by the second PHY (e.g., of node 102_2).
• Timing diagram 350 further includes a signal 356 indicative of a signal observed by the PHY of the second node (e.g., of node 102_2).
• timing diagram 350 further depicts thresholds 358A and 358B (i.e., for detecting a signal having an amplitude that is less than expected), and a collision signal 360, which may be indicative of a collision.
• the absolute value of the amplitude of signal 356 does not exceed thresholds 358A and 358B, the amplitude of signal 356 is less than expected (i.e., compared to if only the PHY of the second node was transmitting). Because the amplitude of signal 306 is less than expected, it may be determined that the first PHY and the second PHY are transmitting simultaneously (here, out of phase).
• a collision detection operation may be performed during a specified amount of time during signal transmission (e.g., to avoid later collision that may cause packet loss). More specifically, for example, collision detection may be applied only within a specified bit time (e.g., first 512 bits) (e.g., started in response to signal transmission). In at least some of these embodiments, the remaining duration of signal transmission (e.g., after the 512 bit time) may be used for other signal detection, as a non-limiting example, other signal detection may include carrier signal detection.
• a specified bit time e.g., first 512 bits
• the remaining duration of signal transmission e.g., after the 512 bit time
• other signal detection may include carrier signal detection.
• FIG. 4 depicts a timing diagram 400 including a time period 402 wherein a PHY of a first node (e.g., of node 102 1 of FIG. 1) transmits (“Remote Tx”), and a time period 404 wherein a PHY of a second node (e.g., of node 102 1 of FIG. 1) transmits (“Local Tx”). Further, the PHY of the second node (e.g., node of 102 1 of FIG. 1) receives the transmitted signal (“Local Rx”) during each of time period 402 and time period 404. Timing diagram 400 further depicts time periods 410 and 412, wherein other signal threshold detection is performed at the PHY of the second node.
• Timing diagram 400 further depicts a time period 411, wherein a collision threshold detect is performed at the PHY of the second node.
• time period 411 which starts in response to signal transmission by the PHY of the second node, has a programmable duration.
• time period 411 may have a bit time duration of approximately 512 bits.
• a signal detector of a PHY may be used for collision threshold detect (e.g., during a transmit mode), and thus in these embodiments, other signal detect may not be performed during time period 411.
• a PHY may include circuitry (e.g., two signal detectors) configured to simultaneously perform other signal threshold detect and collision threshold detect.
• FIG. 5 illustrates an example PHY 500, in accordance to various embodiments of the disclosure.
• PHY 500 is provided as an example PHY configuration that may be used for carrying out various embodiments disclosed herein; however, the disclosure is not limited to any specific PHY configuration, and other configurations may be within the scope of the disclosure.
• PHY 106 of FIG. 2 may include PHY 500.
• PHY 500 includes transmit circuitry 502, which may be configured for communicating transmit data to communication bus 504 from a MAC (e.g., MAC 108 of FIG. 2).
• bus 504 may a part of communication bus 104 of FIG. 1 and FIG. 2.
• Communication bus 504, which may be used for both transmitting and receiving data, may include a single twisted pair (e.g., an Unshielded Twisted Pair, or UTP).
• PHY 500 further includes a signal detector 506 and collision logic 508.
• signal detector 506 may be configured to perform signal threshold detection during a time period associated with a collision threshold detect (e.g., time 411 of FIG. 4), and collision logic 508 may be configured to detect a collision in response to one or more signal thresholds detected by signal detector 506.
• PHY 500 may further include a calibration unit 510 for tuning signal detector 506, as a non-limiting example, by tuning one or more threshold values (for example, threshold values stored at signal detector 506) and/or for tuning collision logic 508 with one or more parameters (e.g., a programmable bit time for collision detection).
• signal detector 506 may be configured to detect signals observed at communication bus 504 that are outside specified thresholds. More specifically, a signal INPUT (e.g., a differential signal RXP, RXN shown in FIG. 6) of bus 504 may be observed (e.g., observed at p and n terminals operably coupled to a single twisted pair type cable) at signal detector 506. Signal detector 506 may be configured to detect if an amplitude of INPUT is outside a threshold, and in response convey to collision logic 508 a logic “1” for signal det out, and detect if an amplitude of INPUT is inside a threshold, and in response convey to collision logic 508 a logic “0” for signal det_out.
• a signal INPUT e.g., a differential signal RXP, RXN shown in FIG. 6
• Signal detector 506 may be configured to detect if an amplitude of INPUT is outside a threshold, and in response convey to collision logic 508 a logic “1” for
• collision logic 508 may be configured to transmit a collision detection signal (e.g., signal 310 of FIG. 3A or signal 360 of FIG. 3B), which may be received at a MAC (e.g., MAC 108 of FIG. 2).
• a collision detection signal e.g., signal 310 of FIG. 3A or signal 360 of FIG. 3B
• MAC e.g., MAC 108 of FIG. 2.
• a 10SPE PHY may operate in a half-duplex mode, and thus, in conventional devices, systems, and/or networks, at least some circuitry of the 10SPE PHY (e.g., signal detector 506) may not be used during a transmit mode.
• signal detector 506 which may be used to detect other signal thresholds (e.g., carrier signal thresholds for carrier sense) including during modes other than transmit (e.g., during a receive mode), may be used to detect collisions (e.g., during “collision detection” (also referred to herein as a “collision detection operation”)) during a transmit mode (i.e., while a signal is being transmitted by circuitry 502).
• collision detection may be performed during a specified amount of time (e.g., a programmable bit time) during signal transmission.
• a bit count i.e., a number of bits transmitted by circuitry 502
• collision logic 508 Upon a bit count being equal to a specified bit number (e.g., 512), a collision detection operation may be terminated.
• a collision detection operation may be initiated at the PHY, and bits transmitted by transmit circuitry 502 may be monitored and counted by collision logic 508 in a bit count that represents the number of bits transmitted while collision logic 508 is counting.
• a collision detection operation may be terminated (e.g., via failing to process and/or utilize a signal (e.g., signal det_out) within signal detector 506).
• FIG. 6 illustrates an example signal detector 600, according to various embodiments of the disclosure.
• signal detector 506 of FIG. 5 may include signal detector 600.
• signal detector 600 includes a comparator 602, a comparator 604 and an OR gate 606.
• Each comparator 602 and 604 may be tuned via a threshold control signal thrsh cntl ⁇ X:0>, which may be generated via, for example, calibration unit 510 of FIG. 5.
• Operation of a signal detector, such as signal detector 600 will be known to a person having ordinary skill in art, and thus some details regarding the operation of signal detector 600 will not be described.
• comparator 602 may detect if a positive differential signal RXP has reached a first threshold value or not. If so, an output D1 of comparator 602 is a “1.” Similarly, comparator 604 may be used to detect if a negative differential signal RXN has reached the first threshold value (e.g., a negative of the positive threshold value) or not.
• first threshold value e.g., a negative of the positive threshold value
• an output D2 of comparator 604 is a “1.” If either comparator 602 or comparator 604 convey a “1,” OR gate 606 will convey a “1.” Notably, since a differential signal continuously toggles between its positive amplitude and negative amplitude, the outputs of comparators 602 and 604 (i.e., outputs D1 and D2, respectively) may not necessarily be a consecutive “1,” however, the output of OR gate 606 may be a consecutive “1.” The result of OR gate 606 is thus a consecutive “1,” or high potential signal, only when the absolute value of the observed signal is greater than the first threshold value.
• collision threshold detection may be based on different threshold values. More specifically, in one example, comparators 602 and 604 may programmed with a first threshold value for detecting amplitudes that are greater than expected amplitudes. In this example, if detector output signal det_out includes a high potential signal, i.e., a “1,” it may be determined that a received signal (e.g., differential signal RXP, RXN) has an amplitude that is equal to or greater than the first threshold value (e.g., a thus a collision has occurred). Otherwise, it may be determined that the received signal (e.g., differential signal RXP, RXN) has an amplitude that is less than the first threshold value.
• a received signal e.g., differential signal RXP, RXN
• detector output signal det out includes a high potential signal longer than a predetermined time (e.g., a few nanoseconds) (i.e., differential signal RXP, RXN stays above (i.e., greater than) the first differential threshold value for the predetermined time), it may be determined that a collision has occurred. Otherwise, it may be determined that a collision has not occurred.
• comparators 602 and 604 may programmed with a second, lower threshold value for detecting amplitudes that are less than expected amplitudes.
• detector output signal det out includes a low potential signal
• a received signal e.g., differential signal RXP, RXN
• the second threshold value e.g., a thus a collision has occurred
• collision threshold detection may be characterized as detecting excursions outside a ranged defined by the first threshold and the second threshold. The result of OR gate 606 is thus a consecutive “0,” or low potential signal, only when the absolute value of the observed signal is less than the second threshold value.
• detector output signal det out includes alow potential signal longer than a programmed time (e.g., a few nanoseconds) (i.e., differential signal RXP, RXN stays within (i.e., less than) the second differential threshold value for the predetermined time), it may be determined (e.g., by collision logic 508) that a collision has occurred. Otherwise, it may be determined that a collision has not occurred.
• a programmed time e.g., a few nanoseconds
• Signal detector 600 is provided as an example signal detector, and embodiments disclosed herein are not limited to a specific signal detector. Rather, any suitable signal detector may be used for carrying out various embodiments of the disclosure, including, without limitation, using multiple signal detectors.
• the collision detect signal (e.g., generated via collision logic 508 of FIG. 5) may be used for controlling operation of an associated node. More specifically, for example, the collision detect signal may be conveyed to a MAC (e.g., MAC 108 of FIG. 2), and if a collision detect signal is indicative that a collision has occurred, the MAC may cause the node to stop transmitting. More specifically, in response to detecting a collision, the MAC may cease any further transmission, or cease any further transmission for at least a predetermined back off time.
• a MAC e.g., MAC 108 of FIG. 2
• FIG. 7 is a flowchart of an example method 700 of operating a network, such as a 10SPE network.
• Method 700 may be arranged in accordance with at least one embodiment described in the present disclosure.
• Method 700 may be performed, in some embodiments, by a device, system, or network, such as network 100 of FIG. l,node 102 of FIG. 2, PHY 500 of FIG. 5, and signal detector 600 of FIG. 6, and/or one or more of the components thereof, or another system or device.
• method 700 may be performed based on the execution of instructions stored on one or more non-transitory computer- readable media.
• various blocks may be divided into additional blocks, combined into fewer blocks, or eliminated, depending on the desired implementation.
• Method 700 may begin at block 702, where a bit time for performing collision detection may be programmed, and method may proceed to block 704. More specifically, for example, calibration unit (e.g., calibration unit 510 of FIG. 5) may convey one or more signals to collision logic 508 to program collision logic 508 with the bit time (e.g., 512 bits).
• calibration unit e.g., calibration unit 510 of FIG. 5
• the bit time e.g., 512 bits
• a signal detector may be programmed with one or more the threshold values. More specifically, calibration unit (e.g., calibration unit 510 of FIG. 5) may convey a threshold control signal to signal detector (e.g., signal detector 506 of FIG. 5) for programming the signal detector with a threshold value.
• the signal detector e.g., signal detector 506
• the signal detector may be programmed with a first threshold value during a first phase (e.g., a first number of bits (e.g., 256 bits)) of the collision threshold detection operation
• the signal detector may be programmed with a different threshold value during a second phase (e.g., a second number of bits (e.g., 256 bits)) of the collision detection operation.
• multiple instances of signal detector 506 may be provided, each provided with a respective threshold value.
• a first signal is transmitted to a shared bus, and method 700 may proceed to block 708.
• a PHY of node 102 2 (see FIG. 1) of a 10SPE network may transmit a signal to bus 104 (see FIG. 1).
• a second signal at the shared bus may be observed, and method 700 may proceed to block 710. More specifically, for example, the PHY of node 102_2 (see FIG. 1) may observe the second signal (e.g., input signal INPUT of FIG. 5) while transmitting the first signal. In one embodiment, a differential signal may be observed (e.g., at a differential input) and the differential signal may be representative of the second signal.
• the PHY of node 102_2 may observe the second signal (e.g., input signal INPUT of FIG. 5) while transmitting the first signal.
• a differential signal may be observed (e.g., at a differential input) and the differential signal may be representative of the second signal.
• an amplitude of the observed signal may be compared to a number of threshold values, and method 700 may proceed to block 712.
• the absolute value of the amplitude of the observed signal may be compared to a first set of threshold values (e.g., threshold values 308A and/or 308B of FIG. 3A) and/or second set of threshold values (e.g., threshold values 358A and/or 358B of FIG. 3B).
• a first phase e.g., a first number of bits
• the amplitude of the observed signal may be compared (e.g., via signal detector 506 of FIG.
• the amplitude of the observed signal may be compared (e.g., via signal detector 506 of FIG. 5) to the second set of threshold values (e.g., thresholds 358A and/or 358B of FIG. 3B) to determine if the absolute value of the amplitude of the observed signal is less than the second set of threshold values (i.e., less than expected).
• collision logic e.g., collision logic 508 of FIG. 5 may determine, based on a detection signal (e.g., signal det_out from signal detector 506 of FIG. 5), whether or not a collision has occurred. More specifically, for example, in response to the absolute value of the amplitude of the observed signal being greater than the first differential threshold value (e.g., thresholds 308A and/or 308B of FIG. 3A) or less than the second differential threshold value (e.g., thresholds 358A and/or 358B of FIG. 3B), it may be determined that a collision has occurred.
• first differential threshold value e.g., thresholds 308A and/or 308B of FIG. 3A
• second differential threshold value e.g., thresholds 358A and/or 358B of FIG. 3B
• a collision detection process (e.g., after expiration of the programmable bit time (e.g., 512 bits) may be terminated. More specifically, for example, in response to a bit count (e.g., determined via transmit circuitry 502) that matches a programmed bit time (e.g., at collision logic 508), the collision detection process may be terminated.
• signal detect may be set for a receive mode, and more specifically, set to use other signal threshold values associated with, for example, a period of time for other signal threshold detect 412 of FIG. 4.
• method 700 may be implemented in differing order.
• the outlined operations and actions are only provided as examples, and some of the operations and actions may be optional, combined into fewer operations and actions, or expanded into additional operations and actions without detracting from the essence of the disclosed embodiment.
• method 700 may include oversampling the signal generated by a signal detector (e.g., to enhance reliability and/or accuracy). More specifically, for example, for a bit unit integral of X nanoseconds, the received signal may be sampled N times. In other words, N samples of the received signal may be processed per bit time (e.g., per 80 nanoseconds). More specifically, as one example, a sample of the received signal may be processed every 10 nanoseconds.
• Various embodiments, as disclosed herein, may be related to a low power, quick, and efficient collision detection method, as associated circuity, which may only require a small area.
• Various embodiments of the present disclosure may be implemented is 10SPE networks for various applications, such as automotive application, industrial applications, server backplanes, without limitation. Further, various embodiments of the disclosure may be applicable to building, elevators, lighting, industrial in-field, Internet of Things (IOT), without limitation.
• IOT Internet of Things
• module or “component” may refer to specific hardware implementations configured to perform the actions of the module or component and/or software objects or software routines that may be stored on and/or executed by general purpose hardware (e.g., computer-readable media, processing devices, etc.) of the computing system.
• general purpose hardware e.g., computer-readable media, processing devices, etc.
• the different components, modules, engines, and services described in the present disclosure may be implemented as objects or processes that execute on the computing system (e.g., as separate threads). While some of the system and methods described in the present disclosure are generally described as being implemented in software (stored on and/or executed by general purpose hardware), specific hardware implementations or a combination of software and specific hardware implementations are also possible and contemplated.
• any disjunctive word or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms.
• the phrase “A or B” should be understood to include the possibilities of “A” or “B” or “A and B.”
• Embodiment 1 A method of operating a physical layer (PHY) of a 10SPE network, comprising: transmitting a first signal from a node to a shared bus; observing a second signal that is at the shared bus during at least a portion of the transmitting; and detecting a collision on the shared bus in response to detecting that the observed second signal being one of greater than a first threshold value and less than a second threshold value.
• PHY physical layer
• Embodiment 2 The method according to Embodiment 1, further comprising comparing an amplitude of the observed second signal to at least one of the first threshold value and the second threshold value.
• Embodiment 3 The method according to any of Embodiments 1 and 2, wherein comparing the amplitude of the observed second signal to at least one of the first threshold value and the second threshold value comprises comparing the amplitude of the observed second signal to both of the first threshold value and the second threshold value.
• Embodiment 4 The method according to any of Embodiments 1 through 3, wherein comparing the amplitude of the second signal to at least one of the first threshold and the second threshold comprises comparing an amplitude of a differential signal to at least one of the first threshold value and the second threshold value.
• Embodiment 5 The method according to any of Embodiments 1 through 4, wherein detecting the collision comprises detecting the collision during a programmable bit time.
• Embodiment 6 A method of operating a single pair Ethernet physical layer (PHY), comprising: transmitting a first signal to a shared bus; and performing collision threshold detection while transmitting the first signal and in response to the first signal being transmitted, the performing collision threshold detection including: observing an amplitude of a second signal at the shared bus; and determining a collision has occurred in response to an absolute value of the observed amplitude of the second signal being one of greater than a first threshold value and less than a second threshold value.
• PHY single pair Ethernet physical layer
• Embodiment 7 The method according to Embodiment 6, wherein observing the amplitude of the second signal comprises observing the amplitude of a differential signal.
• Embodiment 8 The method according to any of Embodiments 6 and 7, wherein performing collision threshold detection further comprises: programming a signal detector of the PHY to the first threshold value; comparing, via the signal detector, the absolute value of the amplitude of the second signal to the first threshold value; programming the signal detector of the PHY to the second threshold value; and comparing, via the signal detector, the absolute value of the amplitude of the second signal to the second threshold value, wherein determining the collision has occurred comprises determining the collision has occurred in response to the absolute value of the amplitude of the second signal being one of greater than the first threshold value and less than the second threshold value.
• Embodiment 9 A physical layer (PHY) device, comprising: a transmitter configured to transmit a first signal via a shared bus; a signal detector configured to: configured to observe a second signal at a shared bus during transmission of the first signal; compare an amplitude of the observed second signal to a number of threshold values; and generate a detector output signal based on a comparison of the amplitude of the observed second signal to at least one threshold value of the number of threshold values; and collision logic coupled to the signal detector and configured to: receive the detector output signal; and determine whether a collision has occurred on the shared bus based on the detector output signal.
• PHY physical layer
• Embodiment 10 The device according to Embodiment 9, wherein the signal detector is configured to receive a control signal for programming the at least one threshold value.
• Embodiment 11 The device according to any of Embodiments 9 and 10, further comprising a calibration unit configured to convey one or more controls signals to the signal detector for setting the at least one threshold value.
• Embodiment 12 The device according to any of Embodiments 9 through 11, wherein the signal detector includes: a first comparator configured to receive a differential signal including the second signal and generate a first detection signal; a second comparator configured to receive the differential signal including the second signal and generate a second detection signal; and an OR gate configured to receive the first detection signal and the second detection signal and generate the detector output signal.
• Embodiment 13 The device according to any of Embodiments 9 through 12, wherein the signal detector is further configured to detect incoming signals in a receive mode.
• Embodiment 14 The device according to any of Embodiments 9 through 13, wherein the collision logic is configured to sample the detector output signal at a rate of approximately one sample per 10 nanoseconds.

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