Abstract:
Aspects for performing localized diagnostics in a station of a home phoneline networking alliance (HPNA) network are described. The aspects include providing a network state and control register comprising a plurality of bits to indicate status of a network state machine of an HPNA media access controller (MAC). A test mode bit is also provided as one of the plurality of bits in the network state and control register. The test mode bit allows overriding of one or more other bits in the network state and control register to direct changes to the network state machine logic state and diagnose performance in response to the changes.

Description:
FIELD OF THE INVENTION 
     The present invention relates to home phoneline networking alliance (HPNA) networks, and more particularly to network state diagnostics testing within a station of an HPNA network. 
     BACKGROUND OF THE INVENTION 
     As the personal computer (PC) has become more prevalent as a mass consumer item, many people have multiple PCs in their houses. With multiple PCs, it becomes desirable to network the computer together for communication with each other. Having the computers connected in a network allows many advantages, including the ability to share a single printer between computers, use a single Internet connection, share files, play games that allow multiple users at different computers, and send the output of a device like a DVD player or Webcam to the other computer(s). 
     A networking approach that utilizes phone lines within a home has been developed based on the specifications of the Home Phoneline Networking Alliance (HPNA) to achieve such communication among multiple computers within a home environment. The HomePNA, as it is commonly called, is regarded generally as easy to install, inexpensive and fast, without requiring any additional wiring, since the phone lines already present in the home are used. HomePNA operates using a method known as Frequency Division Multiplexing (FDM), which allows voice and data to travel on the same wires without interfering with each other, since a standard phone line has enough room to support voice, a high-speed DSL modem, and a home phone line network. 
     The original version of the HPNA standard, HPNA 1.0, operated at a 1 Mbps (megabits per second) communication rate standard. The current specification, HPNA 2.0, is based on technology that operates at a faster 10 Mbps communication rate standard. In order to support both standards in a single device requires some special considerations. 
     For example, given the variety of stations capable of being connected to an HPNA network, diagnostics testing of each possible arrangement to ensure proper functioning becomes difficult. Accordingly, a need exists for a technique that allows localized diagnostics testing of a network state machine within an HPNA network. The present invention addresses such a need. 
     SUMMARY OF THE INVENTION 
     Aspects for performing localized diagnostics in a station of a home phoneline networking alliance (HPNA) network are described. The aspects include providing a network state and control register comprising a plurality of bits to indicate status of a network state machine of an HPNA media access controller (MAC). A test mode bit is also provided as one of the plurality of bits in the network state and control register. The test mode bit allows overriding of one or more other bits in the network state and control register to direct changes to the network state machine logic state and diagnose performance in response to the changes. 
     With the added feature of a test mode bit to a control register in a network state machine of an HPNA MAC, the ability to ensure proper functioning in a station is achieved in an efficient and straightforward manner. These and other advantages of the aspects of the present invention will be more fully understood in the following detailed description in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a preferred embodiment of a home phone line network in accordance with the present invention. 
         FIG. 2  illustrates a block diagram of operational elements of a preferred embodiment of the MAC  108  in accordance with the present invention. 
         FIG. 3  illustrates a network state and control register that includes a state test bit in accordance with a preferred embodiment of the present invention. 
         FIG. 4  illustrates a block diagram of a network state diagnostics process in accordance with a preferred embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention relates to support of diagnostics testing of a network state machine within a station of an HPNA network. The following description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a patent application and its requirements. Thus, the present invention is not intended to be limited to the embodiment shown, but is to be accorded the widest scope consistent with the principles and features described herein. 
       FIG. 1  illustrates a preferred embodiment of a home phone line network in accordance with the present invention. The preferred embodiment of the network complies with the Home Phoneline Networking Alliance (HPNA) specification version 2.0. The network allows multiple computers to communicate through telephone wires typically installed in residential homes. The network comprises a control chip  100 . The chip  100  further comprises a Media Independent Interface (MII)  106 , a Media Access Control (MAC)  108 , and a Physical Layer (PHY)  110 . The chip  100  implements the HPNA 2.0-specification. The chip  100  receives a signal containing data packets through the telephone wires via a phone jack  102 . There is an analog front end (AFE)  104  which processes the Jo signal between the chip  100  and the telephone wires. The chip  100  then processes the packets received in the signal from the AFE  104 , and outputs a signal to the Host MAC  112 . 
       FIG. 2  illustrates a block diagram of operational elements of a preferred embodiment of the MAC  108  in accordance with the present invention. As shown, the MAC  108  includes a Receive Data Path  202 , a Transmit Data Path  204 , a Distributed Fair Priority Queuing (DFPQ)  206 , a Binary Exponential Backoff (BEB)  208 , a Link Integrity  210 , a Network State  212 , a Rate Request Control Frame (RRCF)  214 , and a plurality of registers and Management Information Base (MIB) counters  216 . 
     The Receive Data Path  202  receives data packets from the PHY  110  and sends data packets to the MII  106 . In the preferred embodiment, after each data packet sent by the Receive Data Path  202 , another packet, referred to herein as a “frame status frame”, is sent immediately following. The frame status frame contains certain status information required by subsequent processes. 
     The Transmit Data Path  204  receives data packets from the MII  106  and transmits them to the PHY  110 . 
     The DFPQ  206  and the BEB  208  provide collision resolution. The HPNA 2.0 specification supports both a 10 megabit per second (mbps) data rate and a 1 mbps data rate. The DFPQ  206  provides collision resolution for the 10 mbps data rate, while the BEB  208  provides collision resolution for the 1 mbps data rate. In the preferred embodiment, the PHY  110  will provide a collision detect signal. Either the DFPQ  206  or the BEB  208  will then attempt to resolve the collision. 
     The Link Integrity  210  monitors the physical network conditions. In the preferred embodiment, the Link Integrity  210  updates a link status bit in a link register. The Link Integrity  210  also sends link packets in accordance with the HPNA 2.0 specification. The registers and MIB counters  216  provide programmability to the MAC  108  and handle error event counting. 
     The Network State  212  monitors the current mode of the MAC  108 , i.e., whether the MAC  108  is operating in the 10 mbps data rate mode (“10M8”) or the 1 mbps data rate mode (“1M8”). 
     The RRCF  214  sends a RRCF signal whenever the MAC  108  transitions between data rates. The RRCF is used to perform the rate negotiation function, i.e., to determine what is the data rate to communicate between different stations in a home phone line network. 
     In monitoring the current mode of the MAC  108 , the Network State  212  utilizes a state machine and a control and status register. Normally, the states detected by the state machine are reflected by read-only bits in the control and status register. In accordance with the present invention, however, the control and status register provides a bit that allows overriding of state bits in the control and status register in order to allow performance of localized diagnostics efficiently within a station. For purposes of this discussion, localized diagnostics refer to testing of the state machine&#39;s performance within a single station and without the utilization of a recreation of an entire network structure. 
       FIG. 3  illustrates a network state control and status register  300  in accordance with the present invention. As shown, the register  300  is a 16-bit register with designations provided for each of the bits  0 - 15 , including the designation of bit  15  as a NT (network) State Test Mode bit. While the register of  FIG. 3  represents a preferred embodiment for a 16-bit register, it should be appreciated that this is meant as illustrative and not restrictive, so that other designations and number of bits are possible to provide a network state control and status register with a network state test mode bit in accordance with aspects of the present invention. 
     With a network state control and status register as shown in  FIG. 3 , a process for localized diagnostics testing within a station can occur, as represented by the flow diagram of  FIG. 4 . The process initiates with the setting of the state test mode bit (step  400 ). With the state test mode bit set, the overriding of one of the other bits in the register then occurs (step  402 ). Referring to  FIG. 3 , one of the check bits, shown as detection bit  3 , detection bit  4 , or signaled status bit  5 , could be set in step  402 . As is further shown, for each of these bits, the description indicates the specifications for the operations to be met once in the set state. Thus, by observing how the network state  212  responds to controlled test signals when one of the bits is in the set state, a diagnosis of how well the network state  212  is meeting these specifications commences, as is well appreciated by those skilled in the art (step  404 ). In this manner, the ability to test the network state operations occurs locally within a given station. Of course, the process can be repeated, as desired, to test more than one of the bits. 
     Although the present invention has been described in accordance with the embodiments shown, one of ordinary skill in the art will readily recognize that there could be variations to the embodiments and those variations would be within the spirit and scope of the present invention. Accordingly, many modifications may be made by one of ordinary skill in the art without departing from the spirit and scope of the appended claims.