A network device may exchange information through a network. In some cases, the network device might exchange information through the network via more than one communication port. For example, a mobile computer might exchange information through a first port when it is not connected to a docking station and through a second port when it is connected to a docking station.
Note that one or more signaling characteristics of a network device may need to comply with an industry standard so that the device will be able to communicate with other devices. The presence of an attachment, however, might change the signaling characteristics of the network device. For example, a signaling characteristic of a mobile computer might change when it is attached to a docking station as compared to when it is not attached to the docking station. To ensure that the device complies with a standard in both situations, a system designer might modify a circuit board design by adding inductive components, capacitive components, and/or active transistor elements. Such an approach can be time consuming and increase the cost and complexity of the network device.
The network device 100 includes a communication interface unit 110 to facilitate an exchange of information through a network. The communication interface unit 110 might be, for example, an Ethernet controller adapted to exchange information in accordance with the Institute of Electrical and Electronics Engineers standard number 802.3 entitled “Carrier Sense Multiple Access with Collision Detection (CSMA/CD) Access Method and Physical Layer Specifications” (2002).
The network device 100 is adapted to exchange information through the network via more than one communication port. In particular, the network device 100 includes a first communication port 102 through which the communication interface unit 110 can exchange information.
Moreover, the network device 100 includes a second communication port 152 associated with a detachable attachment (not illustrated in
Note that one or more signaling characteristics of the network device 100 may need to comply with an industry guideline or standard so that the device will be able to communicate with other devices. For example, the network device 100 may need to generate output waveforms in compliance with IEEE 802.3 section 40.6.1.3 entitled “Differential Output Templates.”
In some cases, however, the presence of an attachment might influence the signaling characteristics of the network device 100 (e.g., a signaling characteristic might change when a docking station is attached). For example,
To ensure that the network device 100 complies with the standard (both when the attachment is present and is not present), a system designer might modify a circuit board design by adding passive components, including but not limited to inductors or capacitors, and/or active transistor elements. Such an approach, however, can be time consuming and increase the cost of the network device 100.
According to some embodiments, the network device 100 further includes a storage unit 112 to store one or more corrective values. Moreover, the communication interface unit 110 is able to adjust a signaling characteristic in accordance with the corrective values. For example, the communication interface unit 110 might adjust an output waveform in accordance with a corrective value when an attachment is attached to the second port 152. Note that the storage unit 112 could be part of the communication interface unit 110 or external to the communication interface unit 110.
At 302, a first measurement of a signaling characteristic associated with the network device 100 is performed when the attachment is not attached to the second port 152. At 304, a second measurement of the signaling characteristic is performed when the attachment is attached to the second port 152.
If it is determined that no adjustment is required at 306 (e.g., because both measurements complied with a standard), then no corrective values are needed for the network device 100 at 308.
If it is determined that an adjustment is required at 306 (e.g., because one or both measurements did not comply with a standard), then one or more corrective values are determined for the network device 100 at 310. For example, if an output waveform rises above an upper threshold when an attachment is coupled to the network device 100, the corrective value might indicate that the communication interface unit 110 should reduce the output waveform when the attachment is detected. For example,
Note that the method of
The mobile computer 500 exchanges information through an Ethernet Local Area Network (LAN) via a first port 502, such as an RJ-45 interface and associated stub, when the docking station 550 is not present.
When the docking station 550 is present, the mobile computer 500 exchanges information via a second communication port 552 and associated stub. The docking station 550 transfers information between this second port 552 and another RJ-45 interface 556. According to some embodiments, a magnetic isolation module 514 is provided between the Ethernet controller 510 and the first and second ports 502, 552. The magnetic isolation module 514 may, for example, isolate the silicon of the Ethernet controller 510 from the physical wire associated with the ports 502, 552.
According to some embodiments, the Ethernet controller 510 receives a signal (“RJ Selection”) indicating whether or not the docking station 550 is present. In this case, the Ethernet controller 510 can apply the locally stored corrective values to the output waveform as appropriate based on the received signal.
At 602, the docking station 550 is removed from the mobile computer 500, and at 604 a test fixture is installed on the mobile computer's first port 502. The interface is then characterized at 606. That is, one or more signaling characteristics associated with the mobile computer 500 and/or Ethernet controller 510 may be measured and/or compared to a standard, guideline, or any other performance goal.
At 608, the docking station 550 is connected the mobile computer 500, and at 610 a test fixture is installed on the docking station's RJ-45 port 556. The interface is again characterized at 612. Based on the information collected during the two characterizations of the interface, at 614 one or more corrective values are stored at the Ethernet controller 510. For example, the Ethernet controller 510 might be given a set of corrective values to be applied when the docking station 550 is not present (or set of corrective values to be applied when the docking station 550 is present).
At 702, it is determined whether or not the docking station 550 is currently attached to the second port 552. For example, the mobile computer 500 might receive a signal from the docking station 550 indicating that it is present. The determination might be made, for example, on a periodic basis or upon a change in the presence of the docking station 550.
If the docking station 550 is not currently attached at 704, the mobile computer 510 adjusts an output waveform in accordance with a first set of corrective parameters at 706. For example, Ethernet controller 510 might retrieve the first set of corrective parameters and adjust the amplitude and/or timing associated with the output signal as appropriate.
If the docking station 550 is currently attached at 704, the mobile computer 510 adjusts an output waveform in accordance with a second set of corrective parameters at 708. For example, Ethernet controller 510 might retrieve the second set of corrective parameters and adjust output signal as appropriate.
By using corrective values to adjust the output waveform based on the presence (or absence) of the docking station 550, an efficient way to compensate for various mobile computer 500 board designs may be provided for the Ethernet physical layer interface.
The docking station 850 includes a first interface 854 adapted to be coupled to the second port 852 of the mobile computer 800. The first interface 854 is connected to a second interface 856 of the docking station 856. When the docking station 850 is attached to the mobile computer 800, the Ethernet controller 810 will communicate through the LAN via this second interface 856.
The Ethernet controller 810 may operate in accordance with any of the embodiments described herein. For example, the Ethernet controller 810 might include a storage unit to store a corrective value associated with a network device signaling characteristic. The Ethernet controller 810 might then adjust an output waveform based on the corrective value and the presence of the docking station 850. According to some embodiments, the mobile computer 800 further includes a color display device (e.g., a laptop's display screen).
The following illustrates various additional embodiments. These do not constitute a definition of all possible embodiments, and those skilled in the art will understand that many other embodiments are possible. Further, although the following embodiments are briefly described for clarity, those skilled in the art will understand how to make any changes, if necessary, to the above description to accommodate these and other embodiments and applications.
Although some embodiments have been described wherein a system tester or designer selects corrective values as appropriate, any of the embodiments described herein may be performed using an automated process. For example, a test device might select potential corrective values, characterize the interface, and adjust the potential corrective values until an appropriate set of corrective values are determined.
Moreover, although some embodiments have been described wherein the first measurement is performed when another device is attached and the second measurement is performed when the other device is not attached, any of these embodiments could be performed in the opposite order. In addition, although embodiments have been described with respect to network devices have two ports, embodiments can be used with any multiple number of ports.
The several embodiments described herein are solely for the purpose of illustration. Persons skilled in the art will recognize from this description other embodiments may be practiced with modifications and alterations limited only by the claims.