Abstract:
Systems and methods for operating a gaming machine having an ECC memory are disclosed. One aspect of the systems and methods includes providing a data store in the ECC memory. The data store may be a pool of data blocks, a file system, or a database. Critical data generated during the course of the operation of the gaming machine is stored in the data store. Errors in accessing the data in the ECC may be corrected and logged. In addition, errors in accessing the data in the ECC may cause the system to shut down.

Description:
RELATED APPLICATION  
       [0001]     This application claims the priority benefit of U.S. Provisional Application Ser. No. 60/522,445, filed Oct. 2, 2004, the contents of which are incorporated herein by reference.  
       LIMITED COPYRIGHT WAIVER  
       [0002]     A portion of the disclosure of this patent document contains material to which the claim of copyright protection is made. The copyright owner has no objection to the facsimile reproduction by any person of the patent document or the patent disclosure, as it appears in the U.S. Patent and Trademark Office file or records, but reserves all other rights whatsoever.  
       FIELD  
       [0003]     The present invention relates generally to gaming devices, and more particularly to a gaming device having an error correcting memory. 
     
    
     BACKGROUND  
       [0004]     Today&#39;s gaming machine typically comprises a computerized system controlling a video display or reels that provide wagering games such as slots, video card games (poker, blackjack etc.), video keno, video bingo, video pachinko and other games typical in the gaming industry. Generally, the popularity of such machines with players is dependent on the likelihood (or perceived likelihood) of winning money at the machine and the intrinsic entertainment value of the machine relative to other available gaming options. Players also appreciate the reliability of a gaming machine, as do the casino operators. Shrewd operators consequently strive to employ the most entertaining, exciting, and reliable machines available because such machines attract frequent play and hence increase profitability to the operator.  
         [0005]     Currently, microprocessor-based gaming machines, as well as most microprocessor-based devices use a direct access data storage mechanism commonly referred to in the industry as Random Access Memory (RAM). RAM is immediately accessible by the processor with no additional software required (as in the case of disk drives). The content of this memory is typically critical to the operation of the gaming machine and is continuously changing as it is read and written, as when game play occurs. In addition, many jurisdictions require that critical data be maintained across power cycles and resets of the gaming machine.  
         [0006]     One drawback of RAM is that it is power dependent and does not retain the current state of the computer&#39;s operation when power is removed. A further drawback with many forms of RAM is that errors may occur in the memory that corrupt the data. Some systems have attempted to mitigate this problem by maintaining duplicate copies of critical data in two separate memory sections. Unfortunately, this leads to increased system costs and potential decrease in system performance due to the need to copy the critical data.  
       SUMMARY  
       [0007]     The above-mentioned shortcomings, disadvantages and problems are addressed by the present invention, which will be understood by reading and studying the following specification.  
         [0008]     Systems and methods for operating a gaming machine having an ECC (Error Correcting Code) memory are disclosed. One aspect of the systems and methods includes providing a data store in the ECC memory. The data store may be a pool of data blocks, a file system, or a database. Critical data generated during the course of the operation of the gaming machine is stored in the database. Errors in accessing the data in the ECC may be corrected and logged. In addition, errors in accessing the data in the ECC may cause the system to shut down  
         [0009]     The present invention describes systems, methods, and computer-readable media of varying scope. In addition to the aspects and advantages of the present invention described in this summary, further aspects and advantages of the invention will become apparent by reference to the drawings and by reading the detailed description that follows. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]      FIG. 1  is a perspective view of a gaming machine embodying the present invention;  
         [0011]      FIG. 2  is a block diagram of a gaming control system suitable for operating the gaming machine in  FIG. 1 ;  
         [0012]      FIG. 3  is a block diagram illustrating the interaction between the control system and the ECC memory of a gaming machine according to varying embodiments of the invention;  
         [0013]      FIG. 4  is a flowchart illustrating a method for utilizing ECC memory on a gaming machine according to various embodiments of the invention. 
     
    
     DETAILED DESCRIPTION  
       [0014]     In the following detailed description of exemplary embodiments of the invention, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific exemplary embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that logical, mechanical, electrical and other changes may be made without departing from the scope of the present invention.  
         [0015]     Some portions of the detailed descriptions which follow are presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory. These algorithmic descriptions and representations are the ways used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. An algorithm is here, and generally, conceived to be a self-consistent sequence of steps leading to a desired result. The steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like. It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the following discussions, terms such as “processing” or “computing” or “calculating” or “determining” or “displaying” or the like, refer to the action and processes of a computer system, or similar computing device, that manipulates and transforms data represented as physical (e.g., electronic) quantities within the computer system&#39;s registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices.  
         [0016]     In the Figures, the same reference number is used throughout to refer to an identical component which appears in multiple Figures. Signals and connections may be referred to by the same reference number or label, and the actual meaning will be clear from its use in the context of the description.  
         [0017]     The description of the various embodiments is to be construed as exemplary only and does not describe every possible instance of the invention. Numerous alternatives could be implemented, using combinations of current or future technologies, which would still fall within the scope of the claims. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims.  
         [0018]      FIG. 1  illustrates an exemplary gaming machine  10 , also referred to as a Video Lottery Terminal (VLT), in which embodiments of the invention may be implemented. In some embodiments, gaming machine  10  is operable to conduct a wagering game such as mechanical or video slots, poker, keno, bingo, or blackjack. If based in video, the gaming machine  10  includes a video display  12  such as a cathode ray tube (CRT), liquid crystal display (LCD), plasma, or other type of video display known in the art. A touch screen preferably overlies the display  12 . In the illustrated embodiment, the gaming machine  10  is an “upright” version in which the display  12  is oriented vertically relative to a player. Alternatively, the gaming machine may be a “slant-top” version in which the display  12  is slanted at about a thirty-degree angle toward the player.  
         [0019]     The gaming machine  10  includes a plurality of possible credit receiving mechanisms  14  for receiving credits to be used for placing wagers in the game. The credit receiving mechanisms  14  may, for example, include a coin acceptor, a bill acceptor, a ticket reader, and a card reader. The bill acceptor and the ticket reader may be combined into a single unit. The card reader may, for example, accept magnetic cards and smart (chip) cards coded with money or designating an account containing money.  
         [0020]     In some embodiments, the gaming machine  10  includes a user interface comprising a plurality of push-buttons  16 , the above-noted touch screen, and other possible devices. The plurality of push-buttons  16  may, for example, include one or more “bet” buttons for wagering, a “play” button for commencing play, a “collect” button for cashing out, a help” button for viewing a help screen, a “pay table” button for viewing the pay table(s), and a “call attendant” button for calling an attendant. Additional game specific buttons may be provided to facilitate play of the specific game executed on the machine. The touch screen may define touch keys for implementing many of the same functions as the push-buttons. Other possible user interface devices include a keyboard and a pointing device such as a mouse or trackball.  
         [0021]     A processor controls operation of the gaming machine  10 . In response to receiving a wager and a command to initiate play, the processor randomly selects a game outcome from a plurality of possible outcomes and causes the display  12  to depict indicia representative of the selected game outcome. In the case of slots for example mechanical or simulated slot reels are rotated and stopped to place symbols on the reels in visual association with one or more pay lines. If the selected outcome is one of the winning outcomes defined by a pay table, the processor awards the player with a number of credits associated with the winning outcome.  
         [0022]      FIG. 2  is a block diagram of a control system suitable for operating the gaming machine  10 . Money/credit detector  22  signals a processor  20  when a player has inserted money, tickets, tokens, cards or other mechanism for obtaining credits for plays on the gaming machine through credit mechanisms  14 . Using a button panel  16  and/or a touch screen  18 , the player may select any variables associated with the wagering game and place his/her wager to purchase a play of the game. In a play of the game, the processor  20  generates at least one random event using a random number generator (RNG) and provides an award to the player for a winning outcome of the random event. Alternatively, the random event may be generated by a remote computer using an RNG or pooling schema and then transmitted to the gaming machine. The processor  20  operates the display  12  to represent the random event(s) and outcome(s) in a visual form that can be understood by the player. In addition to the processor  20 , the control system may include one or more additional slave control units for operating the display  12  and any secondary displays.  
         [0023]     System memory  24  stores control software, operational instructions and data associated with the gaming machine. In one embodiment, the system memory  24  comprises a separate read-only memory (ROM) and battery-backed random-access memory (RAM). However, it will be appreciated that the system memory  24  may be implemented on any of several alternative types of memory structures or may be implemented on a single memory structure.  
         [0024]     A payoff mechanism  26  is operable in response to instructions from the processor  20  to award a payoff to the player. The payoff may, for example, be in the form of a number of credits. The number of credits is determined by one or more math tables stored in the system memory  24 .  
         [0025]     ECC (Error Correction Code) memory  28 , in addition to system memory  24 , provides storage for software and data associated with the gaming machine. ECC memory is capable of detecting single-bit and multiple-bit errors. In general, ECC memory uses an algorithms to encode information in a block of bits that contains sufficient detail to permit the recovery of a single bit error in the protected data. ECC memory may use groupings of 7 bits to protect 32 bits, or 8 bits to protect 64 bits. The ECC memory may correct single-bit errors on the fly, that is, the error is corrected with no notification to the operating system or application. Thus the correction of single-bit errors occurs transparently to the system. In alternative embodiments, the correction of single-bit errors may be reported to the operating system. Many forms of ECC memory are available for use by those skilled in the art.  
         [0026]     In addition, ECC memory may detect, but not correct, errors of 2, 3 or even 4 bits, in addition to detecting and correcting single-bit errors. In some embodiments, ECC memory handles these multi-bit errors by generating a non-maskable interrupt (NMI).  
         [0027]     In some embodiments, ECC memory  28  may comprise battery backed RAM, including battery backed SRAM (Static RAM). In alternative embodiments, ECC memory  28  may comprise MRAM (magnetoresistive or magnetic RAM). Generally speaking, MRAM is a non-volatile RAM memory technology that uses magnetic charges to store data instead of electric charges, such as those used in SRAM and DRAM technologies. In further alternative embodiments, NVRAM  308  may be FRAM (Ferroelectric RAM). MRAM and FRAM are desirable, because they do not require battery backup in order for the memory to retain data. It should be noted that any of these memory types may also be used for general purpose memory  24 .  
         [0028]      FIG. 3  is a block diagram providing further details regarding the interrelationship between the processor  20 , system memory  24  and ECC memory  28  components in a gaming machine. In some embodiments, system memory  24  includes one or more gaming applications  302  executable by processor  20 .  
         [0029]     During their operation, gaming applications  302  may need to read and write data to system memory  24  and to a data store  306  maintained on ECC memory  28 .  
         [0030]     The data stored in data store  306  may include critical data. Critical data is generally data that is maintained across reboots or power cycles for the gaming machine. Critical data may also include data that must be reported to one or more of the various regulatory agencies that control gaming in a jurisdiction. Examples of critical data may include one or more of the following: 
        Number of winning outcomes     Payout for the machine     Wagering details (e.g. number of lines wagered, number coins wagered etc.)     Coin-in amounts and denominations        
 
         [0035]     In some embodiments, data store  306  may be treated as a single memory directly available to a gaming application, as is the illustrated by gaming application  302 . 3  directly accessing data store  306 . In alternative embodiments, data store  306  may be organized as a set of one or more data pools that may be allocated to gaming applications  302 .  
         [0036]     In some embodiments, data store  306  is managed by a data store manager  304 . In these embodiments, access to data store  306  by applications  302  is through the data store manager, as illustrated by gaming applications  302 . 1  and  302 . 3 .  
         [0037]     In some embodiments, data store  306  comprises a file system. Data store  304  may be a file system component of an operating system.  
         [0038]     In alternative embodiments, data store  306  is a database and data store manager  304  is a database manager. In varying embodiments, data store  306  may be a relational database, a hierarchical database, an object orient database, or an XML (eXtensible Markup Language) database.  
         [0039]     In some embodiments, multiple sections of ECC memory  28  may contain different data stores  306 . The ECC memory sections  28  and corresponding data stores  306  may be read-only containing static data, read-write containing dynamic data, or any combination of the two.  
         [0040]      FIG. 4  is a flowchart illustrating a method  400  for using an ECC memory on a gaming machine. The method to be performed by the operating environment constitutes computer programs made up of computer-executable instructions. Describing the method by reference to a flowchart enables one skilled in the art to develop such programs including such instructions to carry out the method on suitable processors for gaming machines (the processor or processors of the computer executing the instructions from computer-readable media). The method illustrated in  FIG. 4  is inclusive of acts that may be taken by an operating environment executing an exemplary embodiment of the invention.  
         [0041]     Method  400  begins by accessing the ECC memory (block  402 ). The access may be by a gaming application, by a data store manager, or by an operating system. The access may be to read data from the ECC memory or write data to the ECC memory. As an example, critical data may written to the ECC Memory.  
         [0042]     Occasionally, as a result of an access to ECC memory, the control system may receive a notification of an error in accessing the ECC memory (block  404 ). The error may be a single bit error or a multiple bit error (block  406 ). In some embodiments, notifications regarding single bit errors may not be received, but may be queried by the control system.  
         [0043]     In the case of single bit errors, the system may log the error (block  408 ). The log may then be used to determine if there is a pattern of single-bit errors indicating that a portion or all of the ECC memory is unreliable.  
         [0044]     In the case of multiple bit errors, various actions may be performed in order to insure the integrity of a data store on the ECC memory. For example, the control system may initiate a shutdown of the gaming machine (block  410 ). A shutdown may be necessary in order to prevent further corruption of the memory and to preserve the critical data that has already been written to the memory.  
         [0045]     Alternatively, the system may mark a portion of the ECC memory that includes the memory location having the multiple-bit error as “bad” whereby future writes to the ECC memory will not be attempted to the marked portion (block  412 ). As an example, the portion may be added to a “bad block” list for those embodiments where data store  306  is a file system.  
         [0046]     Further, the system may attempt to retry the access (block  414 ). Retrying an access may be useful in those situations where the multiple bit error is a transient error that does not necessarily mean the ECC memory is unreliable.  
         [0047]     It should be noted that the actions described above are not necessarily mutually exclusive. For example, the control system may mark an area in the ECC memory as bad, and also attempt to retry the access using a different portion of the ECC memory.  
       CONCLUSION  
       [0048]     Systems and methods for providing a gaming machine with an ECC memory have been disclosed. The systems and methods disclosed provide a reliable mechanism for storing critical data that does not require redundant copies of memory. Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement which is calculated to achieve the same purpose may be substituted for the specific embodiments shown. This application is intended to cover any adaptations or variations of the present invention.  
         [0049]     The terminology used in this application is meant to include all of these environments. It is to be understood that the above description is intended to be illustrative, and not restrictive. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. Therefore, it is manifestly intended that this invention be limited only by the following claims and equivalents thereof.