US20090203430A1

US20090203430A1 - Hybrid memory system and spin-buffer journaling in a gaming machine

Info

Publication number: US20090203430A1
Application number: US12/027,570
Authority: US
Inventors: Kenneth Walter Peek
Original assignee: International Game Technology
Current assignee: International Game Technology
Priority date: 2008-02-07
Filing date: 2008-02-07
Publication date: 2009-08-13

Abstract

A gaming machine is comprised of a processor, an interface, and a hybrid non-volatile memory component having a byte-addressable non-volatile memory sub-component and a block-addressable non-volatile memory sub-component. The machine is capable of storing critical gaming data or data that is required to be stored pursuant to gaming regulations in an efficient, reliable, and cost-effective manner. The byte-addressable sub-component (the “expensive” memory) has at least three buffers for temporarily storing critical game data and the block-addressable sub-component (the “lower cost” memory) has at least one block for storing game data, wherein critical gaming data is transferred from the byte-addressable sub-component to the block-addressable sub-component, where it is permanently stored. The block-addressable memory may be flash memory. A confirmation is sent from the block-addressable sub-component to the byte-addressable sub-component when the critical gaming data is permanently stored. The critical gaming data is deleted from the byte-addressable sub-component when the confirmation is received. In one embodiment, the byte-addressable sub-component is a memory that continues to store data during a power loss, in contrast to the block-addressable memory, which may lose data during a write operation if a disruption occurs.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to wager gaming machines and memory management. More specifically, it relates to managing gaming machine data using two types of memory and a spin buffering methodology.
2. Description of the Related Art
In a gaming machine network, slow-speed serial lines have kept the amount of data that could be transmitted in the network relatively small. Gaming control board regulations and casino policies were limited by what the technology could provide. For example, increments in meters and a few bytes indicating an action, such as a wheel spin, was all that was typically sent over the network. This required a few bytes of data and was suitable for transmission over serial lines.
When Ethernet was introduced, the speed with which data could be transmitted increased by orders of magnitude. For example, programmers could now wrap data in XML and use other similar techniques. With the introduction of Ethernet, much larger amounts of data could be transmitted and at much faster speeds. Gaming regulatory bodies then required that more data be stored. For example, with Ethernet, 512 byte packets for each event on a gaming machine could now be sent. However, with these new requirements and speed came the significantly increased need for extra storage capacity on a gaming machine. As is known in the art, a gaming machine logs data on the machine and stores the data, for example, in a CMOS nvRAM on the machine. This type of battery-backed non-volatile memory is expensive and now reaches capacity very quickly with the new requirements for storing data for each event, which may be any type of gaming transaction or any synchronous or asynchronous gaming machine event. Gaming machines use nvRAM primarily because of its write speed. Hard drives are typically too slow.
The capacity of non-volatile memory on older gaming machines was, for example, in the 128k range. But what is now needed is more in the range of 16 MB of such memory. The newest AVP i960 gaming machine from IGT, Inc. of Reno, Nev., does not have enough nvRAM now that some gaming control boards are requiring that complete pictures of all the meters and other data be stored by the gaming operator, even if such storage may be on the machine or at another memory source, for example, a server in the gaming network. In another example, in a server-based gaming environment using new protocols that take advantage of Ethernet (e.g., G2S, developed in part by IGT), storage of large amounts of data is needed for game and system log data.

SUMMARY OF THE INVENTION

In one embodiment, a gaming machine is comprised of a processor, an interface, and a hybrid non-volatile memory component having a byte-addressable non-volatile memory sub-component and a block-addressable non-volatile memory sub-component. The byte-addressable sub-component has at least three buffers for temporarily storing critical game data and the block-addressable sub-component has at least one block for storing game data, wherein critical gaming data is transferred from the byte-addressable sub-component to the block-addressable sub-component, where it is permanently stored. A confirmation is sent from the block-addressable sub-component to the byte-addressable sub-component when the critical gaming data is permanently stored. The critical gaming data is deleted from the byte-addressable sub-component when the confirmation is received. In one embodiment, the byte-addressable sub-component is a memory that continues to store data during a power is loss, in contrast to the block-addressable memory, such as flash memory, which may lose data during a write operation if a disruption occurs.
In another embodiment, a method of storing gaming data in a hybrid memory component in a gaming machine is described, where the gaming data is required to be stored is dictated by relevant gaming regulations. The gaming data is received at the hybrid memory component from one or more components in the gaming machine. It is then determined if a byte-addressable non-volatile memory buffer in the hybrid memory component is at maximum storage capacity with the required gaming data. If the buffer is at maximum storage capacity, the gaming data from the buffer is written to a block in the block-addressable non-volatile memory, while the gaming data continues to be stored in the buffer during the writing. If it is not at maximum storage capacity, the buffer continues to receive gaming data from the one or more components. If the writing operation is complete, at the block-addressable non-volatile memory, it is checked if the gaming data has been stored persistently. If the gaming data has been stored persistently in the block-addressable non-volatile memory, a confirmation is sent from the block-addressable non-volatile memory to the byte-addressable non-volatile memory buffer. The gaming data is deleted from the buffer when the confirmation is received, thereby freeing the buffer to receive new data, such that gaming data is not lost if there is a disruption during the writing operation.
In one embodiment, a gaming device capable of storing required gaming data pursuant to wager gaming regulations is described. The device includes a master gaming controller, a hybrid non-volatile memory component having a byte-addressable memory, a block-addressable memory, an FPGA, and a memory. The memory stores computer instructions for performing various operations on the gaming device. In one embodiment, the required gaming data is received at the hybrid memory component from the master gaming controller. It is then determined if a byte-addressable non-volatile memory buffer in the hybrid memory component is at maximum storage capacity with required gaming data. If it is at maximum storage capacity, the required gaming data is written from the buffer to a block in the block-addressable memory, wherein the required gaming data continues to be stored in the buffer during the writing. If it is not at maximum storage capacity, the buffer continues to receive required gaming data from the master gaming controller. If the writing operation is complete, at the block-addressable memory, it is checked if the required gaming data has been journaled or stored persistently. If the required gaming data has been journaled persistently in the block-addressable memory, a confirmation is sent from the block-addressable memory to the byte-addressable memory buffer. The required gaming data is deleted from the buffer when the confirmation is received. In this manner the buffer is free to receive new required gaming data, such that required gaming data being written is not lost if there is a disruption in the gaming device operations during the writing operation. The gaming device is able to store required gaming data pursuant to gaming regulations using a combination of lower-cost non-volatile memory for long-term persistent journaling and higher-cost memory for intermediate buffering of the required gaming data.

BRIEF DESCRIPTION OF THE DRAWINGS

References are made to the accompanying drawings, which form a part of the description and in which are shown, by way of illustration, particular embodiments:

FIG. 1 is an exemplary gaming machine illustrated in perspective view;

FIG. 2 is a partial exemplary architecture for an electronic gaming machine in accordance with one embodiment;

FIG. 3 is a simplified block diagram of an exemplary gaming machine in accordance with a specific embodiment of the present invention;

FIG. 4 is a block diagram showing components of a hybrid memory component that may be used in a gaming machine or in other gaming-related components in accordance with one embodiment of the present invention;

FIG. 5 is a block diagram showing in greater detail byte-addressable non-volatile memory and flash memory;

FIG. 6 is a flow diagram of a process of writing data from byte-addressable non-volatile memory to flash memory in accordance with one embodiment of the spin buffering methods of the present invention;

FIG. 7 is a flow diagram of a process of writing data to byte-addressable non-volatile memory from other components in the gaming machine in accordance with one embodiment;

FIG. 8 is a flow diagram of a process of recovering from an incomplete write operation or any type of error in accordance with one embodiment; and

FIG. 9 is a logical block diagram showing a configuration of a hybrid memory unit in accordance with one embodiment.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

Reference will now be made in detail to specific embodiments of the invention including the best modes contemplated by the inventors for carrying out the invention. Examples of these specific embodiments are illustrated in the accompanying drawings. While the invention is described in conjunction with these specific embodiments, it will be understood that it is not intended to limit the invention to the described embodiments. On the contrary, it is intended to cover alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may be practiced without some or all of these specific details. In addition, well known process operations have not been described in detail in order to not unnecessarily obscure the present invention.
Although the present invention is directed primarily to gaming machines and systems, it is worth noting that some of the apparatuses, systems and methods disclosed herein might be adaptable for use in other types of devices or environments, such that their use is not restricted exclusively to gaming machines and contexts. Such other adaptations may become readily apparent upon review of the inventive devices, systems and methods illustrated and discussed herein. The remainder of the detailed description herein first provides general discussions of gaming machines, gaming machine architectures and conventional MRAM devices. Following that, specific embodiments of specialized gaming machines having alternative gaming machine architectures are provided, after which various methods of use for such gaming machines and gaming systems are provided. Finally, exemplary network and system configurations are given.
Referring first to FIG. 1, an exemplary gaming machine is illustrated in perspective view. Gaming machine 10 includes a top box 11 and a main cabinet 12, which generally surrounds the machine interior (not shown) and is viewable by users. This top box and/or main cabinet can together or separately form an exterior housing adapted to contain a plurality of internal gaming machine components therein. Main cabinet 12 includes a main door 20 on the front of the gaming machine, which preferably opens to provide access to the gaming machine interior. Attached to the main door are typically one or more player-input switches or buttons 21, one or more money or credit acceptors, such as a coin acceptor 22 and a bill or ticket validator 23, a coin tray 24, and a belly glass 25. Viewable through main door 20 is a primary video display monitor 26 and one or more information panels 27. The primary video display monitor 26 will typically be a cathode ray tube, high resolution flat-panel LCD, plasma/LED display or other conventional or other type of appropriate video monitor. Alternatively, a plurality of gaming reels can be used as a primary gaming machine display in place of display monitor 26, with such gaming reels preferably being electronically controlled, as will be readily appreciated by one skilled in the art.
Top box 11, which typically rests atop of the main cabinet 12, may contain a ticket printer 28, a key pad 29, one or more additional displays 30, a card reader 31, one or more speakers 32, a top glass 33, one or more cameras 34, and a secondary video display monitor 35, which can similarly be a cathode ray tube, a high resolution flat-panel LCD, a plasma/LED display or any other conventional or other type of appropriate video monitor. Alternatively, secondary display monitor 35 might also be foregone in place of other displays, such as gaming reels or physical dioramas that might include other moving components, such as, for example, one or more movable dice, a spinning wheel or a rotating display. It will be understood that many makes, models, types and varieties of gaming machines exist, that not every such gaming machine will include all or any of the foregoing items, and that many gaming machines will include other items not described above.
With respect to the basic gaming abilities provided, it will be readily understood that gaming machine 10 can be adapted for presenting and playing any of a number of gaming events, particularly games of chance involving a player wager and potential monetary payout, such as, for example, a wager on a sporting event or general play as a slot machine game, a keno game, a video poker game, a video blackjack game, and/or any other video table game, among others. While gaming machine 10 can typically be adapted for live game play with a physically present player, it is also contemplated that such a gaming machine may also be adapted for game play with a player at a remote gaming terminal. Other features and functions may also be used in association with gaming machine 10, and it is specifically contemplated that the present invention can be used in conjunction with such a gaming machine or device that might encompass any or all such additional types of features and functions. Gaming machines such as these and other variations and types are made by many manufacturers, such as, for example, IGT of Reno, Nev.
With respect to electronic gaming machines in particular, the electronic gaming machines made by IGT are provided with special features and additional circuitry that differentiate them from general-purpose computers, such as a laptop or desktop personal computer. Because gaming machines are highly regulated to ensure fairness, and in many cases are operable to dispense monetary awards of millions of dollars, hardware and software architectures that differ significantly from those of general-purpose computers may be implemented into a typical electronic gaming machine in order to satisfy security concerns and the many strict regulatory requirements that apply to a gaming environment. Descriptions and examples of current gaming machine architectures can be found in a variety of references, and various discussions of hardware and software structures for an electronic gaming machine are disclosed in, for example, commonly assigned U.S. Pat. No. 6,804,763 by Stockdale, et al., entitled “High Performance Battery Backed RAM Interface;” as well as commonly assigned and co-pending U.S. patent application Ser. No. 10/040,239, by LeMay, et al., entitled “Game Development Architecture That Decouples The Game Logic From The Graphics Logic;” and Ser. No. 10/041,242, by Breckner, et al., entitled “Decoupling Of The Graphical Presentation Of A Game From The Presentation Logic,” each of which is incorporated herein in its entirety and for all purposes. A general description of many specializations in electronic gaming machines relative to general-purpose computing machines and specific examples of additional or different components and features found in such electronic gaming machines now follows.
At first glance, one might think that adapting PC technologies to the gaming industry would be a simple proposition, since both PCs and gaming machines employ microprocessors that control a variety of devices. However, because of such reasons as 1) the regulatory requirements that are placed upon gaming machines, 2) the harsh environment in which gaming machines operate, 3) security requirements and 4) fault tolerance requirements, adapting PC technologies to a gaming machine can be quite difficult. Further, techniques and methods for solving a problem in the PC industry, such as device compatibility and connectivity issues, might not be adequate in the gaming environment. For instance, a fault or a weakness tolerated in a PC, such as security holes in software or frequent crashes, may not be tolerated in a gaming machine because in a gaming machine these faults can lead to a direct loss of funds from the gaming machine, such as stolen cash or loss of revenue when the gaming machine is not operating properly.
Accordingly, one difference between gaming machines and common PC based computers or systems is that gaming machines are designed to be state-based systems. In a state-based system, the system stores and maintains its current state in a non-volatile memory, such that in the event of a power failure or other malfunction the gaming machine will return to its current state when the power is restored. For instance, if a player were shown an award for a game of chance and the power failed before the award was provided, the gaming machine, upon the restoration of power, would return to the state where the award was indicated. As anyone who has used a PC knows, PCs are not state machines, and a majority of data is usually lost when a malfunction occurs. This basic requirement affects the software and hardware design of a gaming machine in many ways.
A second important difference between gaming machines and common PC based computer systems is that for regulation purposes, the software on the gaming machine used to generate the game of chance and operate the gaming machine must be designed as static and monolithic to prevent cheating by the operator of gaming machine. For instance, one solution that has been employed in the gaming industry to prevent cheating and satisfy regulatory requirements has been to manufacture a gaming machine that can use a proprietary processor running instructions to generate the game of chance from an EPROM or other form of non-volatile memory. The coding instructions on the EPROM are static (non-changeable) and must be approved by a gaming regulator in a particular jurisdiction and installed in the presence of a person representing the gaming jurisdiction. Any change to any part of the software required to generate the game of chance, such as, for example, adding a new device driver used by the master gaming controller to operate a device during generation of the game of chance, can require a new EPROM to be burnt, approved by the gaming jurisdiction, and reinstalled on the gaming machine in the presence of a gaming regulator. Regardless of whether the EPROM solution is used, to gain approval in most gaming jurisdictions, a gaming machine must demonstrate sufficient safeguards that prevent an operator of the gaming machine from manipulating hardware and software in a manner that gives the operator an unfair or even illegal advantage over a player. The code validation requirements in the gaming industry affect both hardware and software designs on gaming machines.
A third important difference between gaming machines and common PC based computer systems is that the number and kinds of peripheral devices used on a gaming machine are not as great as on PC based computer systems. Traditionally in the gaming industry, gaming machines have been relatively simple in the sense that the number of peripheral devices and the number of functions on the gaming machine have been limited. Further, the functionality of a gaming machine tends to remain relatively constant once the gaming machine is deployed, in that new peripheral devices and new gaming software is infrequently added to an existing operational gaming machine. This differs from a PC, where users tend to buy new and different combinations of devices and software from different manufacturers, and then connect or install these new items to a PC to suit their individual needs. Therefore, the types of devices connected to a PC may vary greatly from user to user depending on their individual requirements, and may also vary significantly over time for a given PC.
Although the variety of devices available for a PC may be greater than on a gaming machine, gaming machines still have unique device requirements that differ from a PC, such as device security requirements not usually addressed by PCs. For instance, monetary devices such as coin dispensers, bill validators, ticket printers and computing devices that are used to govern the input and output of cash to a gaming machine have security requirements that are not typically addressed in PCs. Many PC techniques and methods developed to facilitate device connectivity and device compatibility do not address the emphasis placed on security in the gaming industry. To address some of these issues, a number of hardware/software components and architectures are utilized in gaming machines that are not typically found in general purpose computing devices, such as PCs. These hardware/software components and architectures include, but are not limited to, items such as watchdog timers, voltage monitoring systems, state-based software architectures and supporting hardware, specialized communication interfaces, security monitoring, and trusted memory.
A watchdog timer is normally used in IGT gaming machines to provide a software failure detection mechanism. In a normal operating system, the operating software periodically accesses control registers in a watchdog timer subsystem to “re-trigger” the watchdog. Should the operating software not access the control registers within a preset timeframe, the watchdog timer will time out and generate a system reset. Typical watchdog timer circuits contain a loadable timeout counter register to allow the operating software to set the timeout interval within a certain time range. A differentiating feature of some preferred circuits is that the operating software cannot completely disable the function of the watchdog timer. In other words, the watchdog timer always functions from the time power is applied to the board.
IGT gaming computer platforms preferably use several power supply voltages to operate portions of the computer circuitry. These can be generated in a central power supply or locally on the computer board. If any of these voltages falls out of the tolerance limits of the circuitry they power, unpredictable operation of the computer may result. Though most modern general-purpose computers include voltage monitoring circuitry, these types of circuits only report voltage status to the operating software. Out of tolerance voltages can cause software malfunction, creating a potential uncontrolled condition in the gaming computer. IGT gaming machines, however, typically have power supplies with tighter voltage margins than that required by the operating circuitry. In addition, the voltage monitoring circuitry implemented in IGT gaming computers typically has two thresholds of control. The first threshold generates a software event that can be detected by the operating software and an error condition generated. This threshold is triggered when a power supply voltage falls out of the tolerance range of the power supply, but is still within the operating range of the circuitry. The second threshold is set when a power supply voltage falls out of the operating tolerance of the circuitry. In this case, the circuitry generates a reset, halting operation of the computer.
The standard method of operation for IGT gaming machine game software is to use a state machine. Each function of the game (e.g., bet, play, result) is defined as a state. When a game moves from one state to another, critical data regarding the game software is stored in a custom non-volatile memory subsystem. In addition, game history or “state” information can include information regarding the amount of credits on the machine, the state of any game in progress, data regarding previous games played, amounts wagered, and so forth, any or all of which can be stored in a non-volatile memory device. This feature allows the state of the gaming machine to be recovered in the event of a substantial interruption to the gaming machine, which can include a power outage, a gaming machine reset, a critical hardware malfunction, a critical software malfunction and a gaming machine functional tilt, among other items, as will be readily appreciated. This is critical to ensure that correct wagers, credits and other important informational items are preserved.
Typically, battery backed RAM devices or other similar components are used to preserve this critical data. These memory devices are not used in typical general-purpose computers. Also, the software structure on the gaming machine can include a safe storage manager module that is configured to update the overall state of the gaming machine to the non-volatile storage component or components, preferably on a recurring basis. This safe storage manager can also be configured to restore the gaming machine to a part or all of the overall state stored at a non-volatile storage component. Further details of state based storage and recovery processes in a gaming machine are disclosed in commonly assigned U.S. Pat. No. 6,804,763, which is again incorporated herein by reference in its entirety and for all purposes.
In addition, substantial interruptions to the gaming machine are typically monitored for by one or more system managers, such as, for example, a tilt manager. Machine properties such as power level, temperature, electrostatic level and other factors are monitored, and cautionary signals or tilt generation instructions are sent and acted upon as appropriate when one or more of these properties of the gaming machine crosses a set tolerance level for whatever reason. Details of such property monitoring and tilt generation processes in a gaming machine are disclosed in commonly assigned and co-pending U.S. patent application Ser. No. 09/954,816, by Breckner, et al., entitled “Modular Tilt Handling System,” which is incorporated herein by reference in its entirety and for all purposes. Continuing further, IGT gaming computers normally contain additional interfaces, including serial interfaces, to connect to specific subsystems internal and external to the gaming machine. The serial devices may have electrical interface requirements that differ from the “standard” EIA RS232 serial interfaces provided by general-purpose computers. These interfaces may include EIA RS485, EIA RS422, Fiber Optic Serial, optically coupled serial interfaces, current loop style serial interfaces, and the like. In addition, to conserve serial interfaces internally in the gaming machine, serial devices may be connected in a shared, daisy-chain fashion where multiple peripheral devices are connected to a single serial channel.
IGT gaming machines may alternatively be treated as peripheral devices to a casino communication controller and connected in a shared daisy chain fashion to a single serial interface. In both cases, the peripheral devices are preferably assigned device addresses. If so, the serial controller circuitry must implement a method to generate or detect unique device addresses. General-purpose computer serial ports are not able to do this. In addition, security monitoring circuits detect intrusion into an IGT gaming machine by monitoring security switches attached to access doors in the gaming machine cabinet. Preferably, access violations result in suspension of game play and can trigger additional security operations to preserve the current state of game play. These circuits also function when power is off by use of a battery backup. In power-off operation, these circuits continue to monitor the access doors of the gaming machine. When power is restored, the gaming machine can determine whether any security violations occurred while power was off, such as by software for reading status registers. This can trigger event log entries and further data authentication operations by the gaming machine software.
Trusted memory devices are preferably included in an IGT gaming machine computer to ensure the authenticity of the software that may be stored on less secure memory subsystems, such as mass storage devices. Trusted memory devices and controlling circuitry are typically designed to not allow modification of the code and data stored in the memory device while the memory device is installed in the gaming machine. The code and data stored in these devices may include, for example, authentication algorithms, random number generators, authentication keys, operating system kernels, and so forth. The purpose of these trusted memory devices is to provide gaming regulatory authorities a root trusted authority within the computing environment of the gaming machine that can be tracked and verified as original. This may be accomplished via removal of the trusted memory device from the gaming machine computer and verification of the secure memory device contents is a separate third party verification device. Once the trusted memory device is verified as authentic, and based on the approval of verification algorithms contained in the trusted device, the gaming machine is allowed to verify the authenticity of additional code and data that may be located in the gaming computer assembly, such as code and data stored on hard disk drives.
Mass storage devices used in a general purpose computer typically allow code and data to be read from and written to the mass storage device. In a gaming machine environment, modification of the gaming code stored on a mass storage device is strictly controlled and would only be allowed under specific maintenance type events with electronic and physical enablers required. Though this level of security could be provided by software, IGT gaming computers that include mass storage devices preferably include hardware level mass storage data protection circuitry that operates at the circuit level to monitor attempts to modify data on the mass storage device and will generate both software and hardware error triggers should a data modification be attempted without the proper electronic and physical enablers being present. In addition to the basic gaming abilities provided, these and other features and functions serve to differentiate gaming machines into a special class of computing devices separate and distinct from general purpose computers.
Moving next to FIG. 2, a partial exemplary architecture for the electronic gaming machine of FIG. 1 is illustrated in block diagram format. Although it may be appreciated that this architecture resembles a PC architecture in some ways, there remain various nuances that can be peculiar to such a gaming machine architecture. It will also be appreciated that the various architectural items illustrated represent only a portion of the many possible architectural elements of a gaming machine, that many other such items may also be included and/or substituted for those shown, and that not every item shown must be included. It is also understood that a wide variety of makes and models of hardware components can be used for a given item, and that any such suitable components are contemplated for use in the present invention. It will be further understood that the various items shown are provided for purposes of illustration only, need not be in the particular locations or arrangements shown, much less present at all in a given gaming machine. For example, while primary display 26 is generally at or near the center of the front face of the gaming machine and speakers are located at the gaming machine sides where the top box meets the main cabinet, one or more of these items may be alternatively placed in a variety of other locations or relative arrangements.
As is also shown in FIG. 1, gaming machine 10 generally includes a top box 11 and main cabinet 12. CPU 50, which is preferably the gaming machine MGC or a portion thereof, executes the logic provided by gaming software on the gaming machine or system. Such a CPU can be, for example, a Pentium series processor available from Intel Corporation of Santa Clara, Calif. or a K6 series processor available from AMD Corporation of Sunnyvale, Calif., among others. To increase the performance of this MGC or CPU, data and instructions may be stored in a memory cache 51 directly on the CPU 50 or at some other relatively convenient location (not shown), such as one that might be located directly off of CPU bus 52, for example. For applications with critical data storage requirements, such memory caches are not usually utilized for critical data storage, since data stored in these locations may be lost in the event of a power failure. Thus, a separate non-volatile memory storage device is utilized, such as NVRAM2 81, as detailed further below.
A north bridge 60 is provided essentially as a memory hub adapted to facilitate and convert communications between various signals, such as, for example, CPU bus signals, Peripheral Component Interface (“PCI”) bus signals, and memory bus signals, among others. One example of such another signal can be advanced graphic port (“AGP”) signals, if applicable. Signals for the CPU bus 52, PCI bus 69, memory bus 68, AGP (not shown) and others may differ according to the voltage level, clock rate and bit width. Also, the format of appropriate control signals on each type conduit such as read strobe, write strobe, ready signal for timing, address signals and data signals may vary from conduit to conduit. North bridge 60, which can be any suitable form of suitable memory hub, such as, for example, an ASIC or Field Programmable Gate Array (“FPGA”), among others, enables communications between these and other different types of conduits. For instance, the PCI standard is a well-defined standard used in the personal computer industry, and is maintained by the Peripheral Component Interface Special Interest Group (“PCISIG”) of Portland, Oreg. PCI version 2.1 typically uses a 66 MHz clock rate and a 32 bit wide data signal at 5 volts to send signals. Other versions of PCI using a 133 MHz clock rate and/or a 64 bit wide data signal may also be available. In contrast, the clock rate used to send data signals on or “speed” of CPU bus 52 may be much higher, such as at or above 800 MHz, as will be readily appreciated.
One or more SDRAM units 66 may store various data and items, such as the gaming machine software to be executed by the CPU 50. As is generally known, such gaming machine software generally provides and allows a game to be played on the gaming machine. SDRAM 66 can be in communication with the CPU indirectly via north bridge 60, and with the north bridge directly via a memory bus 68 or other similar communication link. As is generally known in the art, such a memory bus can be relatively fast, operating at a clock rate of at or above 800 MHz, for example. SDRAM 66 can be the primary form of storage used by the gaming machine for high speed data storage and processing during regular gaming machine operations. It will also be readily appreciated that while SDRAM 66 is relatively fast, it is generally a volatile form of memory, and as such must typically be refreshed or restored upon any new gaming machine power up or reset, such as by loading software from a more stable source, such as, for example, a relatively slower hard drive 72 or CD-ROM 73.
North bridge 60 also preferably connects to a wide variety of gaming machine components, peripherals and additional memory hubs via PCI bus 69. Keyboards, printers, audio components, video components, touch screens, player tracking units, coin acceptors, bill validators, network components and the like are all examples of devices that may communicate with CPU 50 via the PCI bus 69. It will be readily appreciated that while several specific examples of PCI bus devices and components are illustrated and discussed as follows, that many more may also be present and connected to the PCI bus of a gaming machine. As one example, an audio controller 61, which may send signals to one or more speakers or other sound projection devices, can be connected to PCI bus 69. Video controller 62 may also be so connected, and can be used to send signals to one or more displays connected to the gaming machine, such as primary display 26, such that a game outcome may be presented to a player playing a game on the gaming machine. Video controller 62 might be installed as part of a video card that includes video memory and a separate video processor. Using the CPU 50, audio controller 61 and video controller 62, high-quality graphics, sound and multimedia presentations may be presented as part of a game play, outcome or other presentation.
A tell-tale board 63 adapted to detect and record various events when the main power to gaming machine 10 is down or completely off can also connect to PCI bus 69. Such events can be recorded to NVRAM1 67, which can be some form of battery backed RAM or flash RAM, for example. As noted above, tell-tale board 63 can be battery powered, and in any event should at least be adapted to receive power from a source other than the main power source (not shown) of the gaming machine. Such a secondary power source becomes necessary if the tell-tale board is to perform its primary function of recording critical event information while the main power is down or off. As also noted above, such recorded events can be, for example, a notice that a main door has been opened, a bill door has been opened, and/or a card cage or “brain box” door has been opened, among others. A network controller 64, which may communicate with one or more networks including a casino local area network (“LAN”) or a wide area network (“WAN”) can also be connected to PCI bus 69. Such a network controller 64 may allow the gaming machine to communicate with devices that provide gaming services, such as an accounting server and a wide area progressive server, among others. The accounting server may poll the gaming machine for accounting information stored in a non-volatile memory storage device, such as NVRAM2 81. The wide area progressive server may receive information stored in NVRAM2 81, such as wagers made on the gaming machine, and may also send information to be stored in an NVRAM, such as the value of a progressive jackpot.
A generic controller 65 is also shown as being connected to PCI bus 69, with such a controller representing any of the numerous other controllers or devices that can also be connected to the PCI bus. Controller 65 could be, for example, a player tracking unit, keyboard, ticket printer, coin acceptor, bill validator, coin hopper or any of various inputs, such as a touch screen or button, for example.
One or more additional information or memory hubs may also be linked along PCI bus 69, such as, for example, a south bridge 70. This south bridge 70 may also separately connect to various additional memory devices, as well as one or more serial ports (not shown), such as those for a bill validator. In one particular example, when a monetary bill, printed ticket or other acceptable indicia of credit is accepted by the bill validator, information regarding the denomination of the bill or value of the ticket or other indicia may be transferred serially using a Netplex interface to the south bridge 70, with Netplex being an IGT proprietary protocol. Such Netplex serial signals can then be converted to PCI standard signals by the south bridge 70 using a Netplex device driver. Other suitable non-proprietary methods of communication, such as those under the RS-232 serial standard, may also be used. The information transferred from the bill validator might be treated as critical game information, whereby non-volatile memory storage such as NVRAM2 81 might be used.
South bridge 70 may contain various components internally, such as a hard drive controller 71, and can be used to connect various stable ROM storage devices to the system, such as hard drive 72, CD-ROM 73 and EPROM1 74, among others. Some of these devices, such as hard drive 72 and CD-ROM 73 can connect to the south bridge 70 via an integrated drive electronics (“IDE”) bus 75 or other similar connection. As is known in the art, a typical IDE bus operates at a speed of about 100 MHz, which is generally appropriate for the access rates of many hard drives and CD-ROM drives. Other devices, such as EPROM1 74, can connect to the south bridge 70 via a basic industry standard architecture (“ISA”) bus 76, which can be relatively slow in comparison to other buses and connections. For example, a typical ISA bus might transmit data at a speed of about 8 MHz, which would be appropriate for an EPROM and other similarly slower components. In many gaming machines, the boot programs used in a power up or restart process tend to be in multiple locations, such as an initial basic input/output system (“BIOS”) at a “BOOT 1” location within EPROM1 74 and an extended BIOS at a “BOOT2” location within EPROM2 82, as discussed in greater detail below. Other components might also connect to south bridge 70 by a universal serial bus (“USB”) (not shown) and/or any of a number of other suitable buses and connections, as will be readily appreciated.
Additional components and storage devices can also be connected to the PCI bus 69 as part of a gaming system extension, such as through an FPGA 80 or another similar logic device or memory hub. FPGA 80 can be, for example, a model XC3S50 FPGA manufactured by Xilinx, Inc. of San Jose, Calif. Alternatively, such a gaming system extension can be another PCI interface device, such as the PLX 9050 made by PLX Technology of Sunnyvale, Calif. Of course, any other similarly suitable device can also be used as a gaming system extension. FPGA 80 or other gaming system extension can include various serial connections that allow communication with several devices, such as player tracking units, wide area progressive systems and casino area networks, among others. Memory units that connect to the PCI bus 69 through FPGA 80 or another similar extension can include, for example, a battery backed RAM or other non-volatile memory unit NVRAM2 81, a boot related memory unit EPROM2 82, and a “black box” EEPROM 83 for storing data and other gaming machine specific information, among others. Of course, multiple FPGAs or other similar extension devices may also connect to PCI bus 69, although only one is illustrated here for purposes of simplicity and discussion.
One use for battery backed RAM or otherwise non-volatile NVRAM2 81 is to preserve a game history or state of the gaming machine. Such a gaming machine history or state can include many details and data items regarding information from a game presentation and/or outcome, including one or more frames from a sequence of frames used in the game outcome or presentation. Such frames may be copied to NVRAM2 81 from frame buffers residing on the video controller 62 or at another location in the gaming machine. As such, NVRAM2 81 is a “safe storage” device for gaming machine 10, and can be connected to PCI bus 69 for a number of reasons. For one, the PCI bus 69 allows for a relatively fast connection (e.g., 66 or 133 MHz) to the CPU 50 from NVRAM2 81 (via FPGA 80, north bridge 60 and the faster CPU bus 52). Such a speedy connection is important, since the software typically does not advance to the next state until the current state is executed or rolled back in a state based transaction system. Execution of each state involves a number of access requests to NVRAM2 81, such that the access rate to this device typically affects the performance of the entire gaming machine or system. Although a faster connection than PCI bus 69 might be desirable, the speed of this bus tends to be on par with the speed of many typical battery backed RAM devices, such that a faster bus would not provide any significant advantage when used with NVRAM2 81.
Other reasons for using a PCI bus in association with NVRAM2 81 or other battery backed RAM can include the fact that there is typically no data caching on a PCI bus, which is an important feature where critical data is being backed up, as well as the ability for items on a PCI bus to be interchangeable and to be tolerant of changes on a main processor board, such as a CPU swap. This permits flexibility in swapping out various gaming machine components without having to make any corresponding changes to the NVRAM2 81 for purposes of compatibility. It is preferable that a gaming machine safe storage component, such as NVRAM2 81, be relatively large, given its critical function of backing up states in a gaming machine. Such an inclusion or use of a large non-volatile memory is usually not a standard component on a PC, thus distinguishing PCs from gaming machines at least in this regard. Further details of safe storage at an NVRAM device are disclosed in the previously noted commonly assigned U.S. Pat. No. 6,804,763 by Stockdale, et al., entitled “High Performance Battery Backed RAM Interface,” which has been incorporated by reference herein in its entirety and for all purposes.
One use for a one time writable ROM such as EPROM2 82 can be that of storage for critical extended BIOS (“BOOT2”), as noted above. In a typical boot up or reset process, the gaming machine is initially directed to the initial BIOS program stored at BOOT1 within the EPROM1 74 connected to south bridge 70. Once this has been booted and acted upon, logic within the BOOT1 direct the gaming machine to the extended BIOS program stored at BOOT2 within the EPROM2 82 connected to FPGA 80. As will be readily appreciated, both of these processes can involve various boot, loading, decryption, authentication and verification processes, and any of a number of suitable encryption techniques may be employed during these processes. For example, a public-key encryption can involve a combination of a private key that is known only to a single host device and a public-key that is given to any other device that wants to communicate securely with the host device. A sending device encrypts a document using the public key from the recipient and its own private key. The receiving device uses the public-key (as provided by the other device) and its own private key to decode the encrypted message. Files may also be authenticated using digital signatures or digital certificates created via the private key of the sender. Such digital certificates permit the recipient to confirm the identity of the sender, as is generally known in the art.
Uses for a “black box” non-volatile RAM device, such as EEPROM 83, can be for storing data specific to the exterior cabinet or physical terminal of a gaming machine or system. Such data can be overall cabinet or terminal based meter data, backup data or code for other gaming machine or system components, and/or other gaming machine or terminal specific information, such as country designations, accounting denominations, machine yield data, progressive jackpot data, volume settings and overall gaming machine configuration data, among others. The need for such overall EEPROMs or other like storage devices typically arises due to gaming regulations, gaming operator desire to track overall data with respect to a machine housing or physical terminal, or both. As such, this “black box” EEPROM 83 can be located on a back plane board of the gaming machine, such that it remains with the exterior housing when the main processor board or “brain box” and/or its associated components are replaced. As is generally known, a “brain box” is typically a sheet metal enclosure within the gaming machine that is adapted to house a number of critical components, such as the MGC or CPU, as well as various memory devices, such as some RAM, NVRAM, the hard drive, and other such components. This brain box can come with a lock, and may be removable from the gaming machine as an entire unit in some cases. EEPROM 83 can then be interfaced to the new “brain box” and/or other components that are newly installed, as will be readily appreciated.
Referring again to FIG. 2, designations for those items that are primarily associated with the main processor board or “brain box,” such that they are typically removed from the gaming machine along with the brain box when it is replaced, are shown as being within brain box region 40. Conversely, those gaming machine items that are primarily associated with the gaming machine exterior housing, such that they remain with the exterior housing while the main processor board is replaced, are seen as being within back plane board region 41. As shown, replacement of a main processor board typically involves the replacement of CPU 50, its cache 51, north bridge 60, SDRAM 66, south bridge 70, hard drive 72, CD-ROM 73, EPROM1 74, FPGA 80, NVRAM2 81, EPROM2 82 and possibly one or more other components, such as generic controller 65. Items that usually remain with the cabinet or exterior housing during a brain box swap can include the “black box” EEPROM 83, as well as audio controller 61 and speakers 32, video controller 62 and main display 26, tell-tale board 63 and its associated NVRAM1 67, and network controller 64, among others.
FIG. 3 is a simplified block diagram of another embodiment of an example gaming machine 200 in accordance with a specific embodiment of the present invention. As illustrated in the embodiment of FIG. 3, gaming machine 200 includes at least one processor 210, at least one interface 206, and memory 216.
In one implementation (not shown), processor 210 and master gaming controller 212 are included in a logic device 213 enclosed in a logic device housing. In the implementation shown in FIG. 3, processor 210 is in logic device 213 which, together with other components described below, are in master gaming controller 212. Processor 210 may include any conventional processor or logic device configured to execute software allowing various configuration and reconfiguration tasks such as, for example: a) communicating with a remote source via communication interface 206, such as a server that stores authentication information or games; b) converting signals read by an interface to a format corresponding to that used by software or memory in the gaming machine; c) accessing memory to configure or reconfigure game parameters in memory according to indicia read from the device; d) communicating with interfaces, various peripheral devices 222 and/or I/O devices 21 1; e) operating peripheral devices 222 such as, for example, card reader 225 and paper ticket reader 227; f) operating various 1/0 devices such as, for example, display 235, key pad 230 and a light panel 216; etc. For instance, processor 210 may send messages including configuration and reconfiguration information to display 235 to inform casino personnel of configuration progress. As another example, logic device 213 may send commands to light panel 237 to display a particular light pattern and to speaker 239 to project a sound to visually and aurally convey configuration information or progress. Light panel 237 and speaker 239 may also be used to communicate with authorized personnel for authentication and security purposes.
Peripheral devices 222 may include several device interfaces such as, for example: card reader 225, bill validator/paper ticket reader 227, hopper 229, etc. Card reader 225 and bill validator/paper ticket reader 227 may each comprise resources for handling and processing configuration indicia such as a microcontroller that converts voltage levels for one or more scanning devices to signals provided to processor 210. In one embodiment, application software for interfacing with peripheral devices 222 may store instructions (such as, for example, how to read indicia from a portable device) in a memory device such as, for example, non-volatile memory, hard drive or a flash memory.
Gaming machine 200 also includes memory 216 which may include, for example, volatile memory (e.g., RAM 209), non-volatile memory 219 (e.g., FLASH memory, EPROMs, battery backed RAM, etc.), unalterable memory (e.g., EPROMs 208), alternate storage 217 (e.g., non-volatile memory implemented using disk drive(s), flash memory, remote storage, etc.), etc. The memory may be configured or designed to store, for example: 1) configuration software 214 such as all the parameters and settings for a game playable on the gaming machine; 2) associations 218 between configuration indicia read from a device with one or more parameters and settings; 3) communication protocols allowing processor 210 to communicate with peripheral devices 222 and I/O devices 211; 4) a secondary memory storage device 215 such as a non-volatile memory device, configured to store gaming software related information (the gaming software related information and memory may be used to store various audio files and games not currently being used and invoked in a configuration or reconfiguration); 5) communication transport protocols (such as, for example, TCP/IP, USB, Firewire, IEEE1394, Bluetooth, IEEE 802.11x (IEEE 802.11 standards), hiperlan/2, HomeRF, etc.) for allowing the gaming machine to communicate with local and non-local devices using such protocols; etc. Typically, the master gaming controller 212 communicates using a serial communication protocol. A few examples of serial communication protocols that may be used to communicate with the master gaming controller include but are not limited to USB, RS-232 and Netplex (a proprietary protocol developed by IGT, Reno, Nev.).
A plurality of device drivers 242 may be stored in memory 216 or separately as shown. Example of different types of device drivers may include device drivers for gaming machine components, device drivers for peripheral components 222, etc. Typically, device drivers 242 utilize a communication protocol of some type that enables communication with a particular physical device. The device driver abstracts the hardware implementation of a device. For example, a device driver may be written for each type of card reader that may be potentially connected to the gaming machine. Examples of communication protocols used to implement device drivers 259 include Netplex 260, USB 265, Serial 270, Ethernet 275, Firewire 285, I/O debouncer 290, direct memory map, serial, PCI 280 or parallel. Netplex is a proprietary IGT standard while the others are open standards. According to a specific embodiment, when one type of a particular device is exchanged for another type of the particular device, a new device driver may be loaded from memory 216 by processor 210 to allow communication with the device. For instance, one type of card reader in gaming machine 200 may be replaced with a second type of card reader where device drivers for both card readers are stored in the memory 216.
In some embodiments, gaming machine 200 may also include various authentication and/or validation components 244 which may be used for authenticating/validating specified gaming machine components such as, for example, hardware components, software components, firmware components, information stored in the gaming machine memory 216, etc.
In some embodiments, the software units stored in the memory 216 may be upgraded as needed. For instance, when the memory 216 is a hard drive, new games, game options, various new parameters, new settings for existing parameters, new settings for new parameters, device drivers, and new communication protocols may be uploaded to the memory from the master gaming controller 104 or from some other external device. As another example, when the memory 216 includes a CD/DVD drive including a CD/DVD designed or configured to store game options, parameters, and settings, the software stored in the memory may be upgraded by replacing a first CD/DVD with a second CD/DVD. In yet another example, when the memory 216 uses one or more flash memory 219 or EPROM 208 units designed or configured to store games, game options, parameters, settings, the software stored in the flash and/or EPROM memory units may be upgraded by replacing one or more memory units with new memory units which include the upgraded software. In another embodiment, one or more of the memory devices, such as the hard-drive, may be employed in a game software download process from a remote software server.
FIG. 4 is a block diagram showing components of a hybrid memory component that may be used in a gaming machine or in gaming-related components, such as accounting systems and player tracking systems, in accordance with one embodiment of the present invention. Various types of gaming data, described in greater detail below, are received from a master gaming controller (or CPU) 402 or other appropriate component in a gaming machine at a non-volatile memory manager 404 which may be implemented as a hardware component or as a software module. Thus, box 404 may represent a hardware or software component or a combination of both. In other embodiments, memory manager 404 may not be required. For example, a more generic data logger component or any component suitable, such as those described above, for managing the writing of all types of game-related data to the non-volatile memory may be used.
A non-volatile memory component 406 may consist of at least two components: a byte-addressable non-volatile memory 408 and a block-addressable non-volatile memory 410. For ease of illustration and discussion, block-addressable non-volatile memory 410 may be referred to as “flash memory” or “flash,” in specific embodiments (and may be a different component from the flash memories described above). For example, it may be implemented as a flash chip or as a compact flash card, although it is understood that other suitable types of memory devices may be used in place of flash memory, such as hard disks, as discussed below. Thus, flash memory is used in but one embodiment of the hybrid memory and spin buffering techniques of the present invention.
FIG. 5 is a block diagram showing in greater detail byte-addressable non-volatile memory 408 and flash memory 410. In one embodiment, byte-addressable non-volatile memory 408 has a series of three or more buffers. The number of buffers needed may depend on the volume of data being sent from the gaming machine components and the manner in which such data is received (e.g., the frequency of “data bursts” from the gaming machine). In one embodiment, a buffer can store 512 bytes. The capacity of a buffer A 502, for example, may depend directly on the size of the block or sectors in flash memory 410 (e.g., 512k, 1024k, 4096k, etc.). Details on deriving the adequate or appropriate size of a buffer to meet the gaming system's needs and the jurisdictional requirements are described below. Also stored in byte-addressable non-volatile memory 408 are “housekeeping” or administrative data 504. In an alternative embodiment, non-volatile memory 408 may have management firmware. In the primary embodiment, the operations of byte-addressable non-volatile memory 408 and flash memory 410 (described below) are managed by memory manager 404.
Flash memory 410 may consist of multiple blocks, such as Block A 508, which in one embodiment has a capacity of 512 bytes. As described below, in other embodiments, the size of a memory block in flash 410 may vary, but is typically a multiple of the sector size. In other embodiments, a hard disc or other rotating platter-type memory device may be used.
FIG. 5 also shows exchange of data from memory 408 to 410 and confirmations from memory 410 to memory manager 404 or directly to byte-addressable memory 408, which are described in the flow diagrams below. In brief, gaming data is written to block-addressable non-volatile memory 410 for persistent storage and confirmations are sent from it to byte-addressable non-volatile memory 408 at specific stages in the operation.
FIG. 6 is a flow diagram of a process of writing data from byte-addressable non-volatile memory to flash memory in accordance with one embodiment of the spin buffering methods of the present invention. It will be understood that not every step provided for is necessary, that other steps might be included, such as start or reboot processes, and that the order of steps might be rearranged as desired for a given application. At step 602 non-volatile memory manager 404 determines whether a buffer in byte-addressable non-volatile memory is in a FULL state by checking housekeeping data. If the buffer is full, the state of the buffer is changed to BUSY (or something similar) in preparation of the writing operation of the data to flash memory (or block-addressable non-volatile memory). At step 606 the data in it is written to a block in block-addressable non-volatile memory. If at step 602 it is determined that the buffer is not FULL, data is continued to be written to the buffer at step 603. In one embodiment at step 602, the non-volatile memory manager 404 continues to check the buffer until the buffer is in a FULL state.
At step 608 memory manager 404 or a logic component in byte-addressable non-volatile memory 406 determines whether the write operation is complete, for example, by checking the contents of the buffer. If the buffer write operation is not complete, the memory manager continues checking. If it is determined that the write operation is complete, the block-addressable non-volatile memory checks whether the data has been stored persistently or made permanent in the flash memory at step 609. If it has not, given that writing is complete, flash memory continues to check whether the data is stored safely. If it has, at step 610 block-addressable memory 410 transmits a confirmation to the byte-addressable buffer or, more generally, sends a confirmation to the non-volatile memory manager 404.
As noted above, if there is a power failure or other disruption during the write operation, none of the data is lost because of the characteristics of byte-addressable non-volatile memory 408 which will continue to store the data that is being written in case of an abnormal event. In other words, the data remains persistent in the buffer until there is a confirmation. In contrast, data in the block may be lost if there is a disruption during the write operation. By sending a confirmation (i.e., data received and persistently stored) to non-volatile memory manager 404, the flash memory is essentially informing byte-addressable non-volatile memory 408 that it is now safe to erase the data and mark the buffer as FREE. Thus, at step 612, the buffer is placed in the FREE state and a block index or pointer is incremented so that non-volatile memory 408 will write to a free block in the next write operation. At this stage the process returns to checking if a buffer is full at step 602.
FIG. 7 is a flow diagram of a process of writing data to byte-addressable non-volatile memory from other components in the gaming machine in accordance with one embodiment. At step 702 non-volatile memory manager 404 or other component in the byte-addressable non-volatile memory 408 reads housekeeping or administrative data for the memory in order to select the next free buffer for receiving data. At step 704 the state of the selected buffer is BUSY or equivalent indicating that it is storing data and no longer free. At step 705 incoming game data is written to the selected buffer. As described in greater detail below, game data is intended to encompass a broad range of types and categories of data, including game state and machine event data, such as actions that occur asynchronously, including button pushes, door opens, bonus events, and the like, among many others.
At step 706 memory manager 404 determines whether the buffer has reached capacity, the size of which may vary in different embodiments. If the buffer is not full, the writing or storing process continues at step 705. If the buffer is full, the state of the buffer is changed to FULL or unavailable at step 708 and the process is complete.
FIG. 8 is a flow diagram of a process of recovering from an incomplete write operation or any type of error in accordance with one embodiment. This process takes place before any normal operations (or before any atypical operations) are allowed to proceed on the gaming machine. It may be run at boot up or start up of the gaming machine after a power failure, tilt, or any other unexpected interruption in the gaming machine operations that may effect the writing of data from byte-addressable non-volatile memory to flash memory 410 and thereby may violate the integrity of data that, by gaming regulation and/or casino policy, is required to be stored.
At step 802 the appropriate component, such as the non-volatile memory manager 404 or master gaming controller 402 determines whether there was a write operation between a byte-addressable buffer and a block in flash memory when the failure occurred. This may be done by checking a state variable of the buffers. The byte-addressable non-volatile memory housekeeping data may also have a block address as well. In one embodiment, the byte-addressable memory housekeeping data or similar data may indicate that “This is where each buffer was at the moment of failure and this is what each buffer was doing (i.e., it was empty, being written to, or being read from) when the failure occurred.”
If there was a write operation in progress, then in one embodiment, portions of data that were written to the block are erased from flash memory. If a hard disc is being used to log the data, the erasing step may not be necessary. Housekeeping data in flash or byte-addressable memory may have data indicating which portions or sectors of flash should be erased. At step 806 the data from the buffer, which is unaffected from the failure, is re-written to the block in flash memory. This process is generally the same as the process described above in FIGS. 6 and 7. In one embodiment, the data is written to the same block in flash that was being used before the power failure or disruption. Housekeeping data may be used to re-initiate the data writing process from the buffer to the block. As noted above, data in the byte-addressable non-volatile memory buffer is not lost. After the write operation is completed and confirmation from flash memory is received, the buffer is marked as FREE so that it may begin storing new data at step 808 at which stage the process is complete.
FIG. 9 is a logical block diagram showing a configuration of a hybrid memory unit that may be used to implement one embodiment. A memory chip 902 has a byte-addressable non-volatile memory component 904 that may be, for example, a non-volatile RAM, such as CMOS, MRAM, PRAM, and other memory types known to those skilled in the art that will continue to store data in the absence of electrical power. Some of these may be battery backed, such as CMOS nvRAM. Also contained in memory chip 902 is a block-addressable memory 906 or, what has been referred to herein as, flash memory. One suitable type of flash memory is single-level per cell NAND-FLASH. For example, a Compact FLASH Card (CF-Card) may be used. The two memory components 904 and 906 are in communication with each other via an FPGA component 908, one implementation of non-volatile memory manager 404 that enables data transfer between the two memory components, maintains housekeeping data, and communicates with other components in the gaming machine. In this manner, the hybrid memory and spin buffering technique of the present invention may be modularized in a single memory single integrated circuit or a component comprising multiple integrated circuits that can be removed from a gaming machine or, conversely, kept in a gaming machine while other components, such as those on or off the main processor board are removed. Of course, other embodiments implementing the hybrid memory may be used in a gaming machine and FIG. 9 shows only one example. For example, a hybrid memory of the present invention may be implemented as a plug-in card or chip.
As described above, one reason the hybrid memory of the present invention is beneficial is because data that is required to be stored (as dictated by gaming regulations) is not lost during a power interruption, during a write operation, or lost due to flash sector damage, if flash memory is used as one component in the hybrid memory. In various embodiments, a buffer in the byte-addressable non-volatile memory 408 is 512 bytes, 1024 bytes, 2048 (2k) bytes, or 4096 (4k) bytes.
Sufficient capacity is needed to satisfy potential, however unlikely, gaming situations and maintain adherence with gaming control board regulations. For example, a gaming jurisdiction may require that transactional data on 100 games, each having a possible 100 secondary games, be stored and accessible at all times. Thus, storage capacity for gaming data for 10,000 games should be available, even if the likelihood that all of it will be needed is small.
In one embodiment, the byte-addressable non-volatile memory, for example, Freescale's magnetoresistive RAM (MRAM), does not require a battery. In another embodiment, it may be a battery-backed CMOS-SRAM or an nvRAM from Simtek. In another embodiment, it may be a phase-change RAM or PRAM.
In one embodiment, the byte-addressable and the block-addressable non-volatile memories are on a main processor board, along with the master gaming controller board in the gaming machine. In another embodiment, it is on a compact flash card with its own controller, for example implemented as an FPGA as shown in FIG. 9 (and shown in FIG. 2). In another embodiment, a portion of the block-addressable memory may be a hard drive, on a server in the gaming network, or on the Internet.
As noted above, a buffer (also referred to in the art as “heaps”) in the byte-addressable non-volatile memory has a state. In one embodiment, these states include FREE, BUSY, FULL, and WRITE. In other embodiments, there may be more states. With respect to buffer size, the size of the buffer may depend on several factors. These include size of a block or sector in flash memory, the amount of data generated, and other relevant factors, discussed in greater detail below.
When a buffer reaches full capacity, non-volatile memory manager software 404 may request a next free buffer in the buffer chain. In one embodiment, a pointer is moved to point to the next available buffer. Concurrently, another buffer may be writing to a block in flash memory, thereby placing the buffer in a WRITE state. When it has finished, the state of the buffer is changed to FREE.
If there is a need to burst a large volume of data within the gaming machine, it is preferable to have more than three buffers (e.g., buffers 502) in the byte-addressable non-volatile memory. Large bursts of data may occur in the gaming machine context under circumstances such as when a data packet is transmitted or “pumped” for each synchronous or asynchronous event. In one scenario, a tilt may cause another tilt until the machine stops operating, triggering a multitude of asynchronous events each represented by one or more data packets, which may be greater than 512 bytes. In one embodiment, the size of the buffer is in accord with the granularity of the block size in the block-addressable non-volatile memory device. For example, a flash memory block size may be 512 bytes, 1024 bytes or 2048 bytes for some flash devices. Some higher density flash devices may have 16k block sizes. In one embodiment, an entire write operation (from byte-addressable memory to block-addressable memory) is performed in one operation to the block device.
In one embodiment, the flash memory or, more broadly, the block-addressable memory, and the byte-addressable memory are kept in the cabinet of the gaming machine while other components of the gaming machine are changed. They may also be kept in other areas of a gaming machine (described in more detail in FIGS. 1 and 2). It is preferable that they be kept together in the event there is a power off during data transfer and the transfer is not complete. For example, the byte-addressable and block-addressable memories can be kept on the main processing board (or on a separate board that is permanently attached to the machine) as a pair, so even if components such as the electronics, slot tray, and the like are changed or replace, then the memory pair may stay with the machine.
One use for non-volatile memory is to preserve a game history or state of the gaming machine. Such a gaming machine history or state can include many details and data items regarding information from a game presentation and/or outcome, including one or more frames from a sequence of frames used in the game outcome or presentation. Such frames may be copied to non-volatile memory from frame buffers residing on video controller 62 or at another location in the gaming machine.
Non-volatile memory plays a significant role in the normal operation of a gaming machine. It may store data classified as permanent or temporary data. The permanent type of data is described herein as critical data. Critical data comprises data considered to be highly important and relates to the current or previous state(s) of a gaming machine. Examples of critical data include game history information, security information, accounting information, player tracking information, wide area progressive information, game state information, game usage information, game transactional information, game meter information, bonus of game information, player input information, and license information. Some of these types of data are described in greater detail below, or any “critical” game related data. Critical data such as the amount of funds credited to or paid out from a gaming machine may be stored permanently in non-volatile memory as accounting information. This critical accounting information would reflect its current and prior states over successive rounds of play.
Among the types of commonly preserved data is so-called “critical data” or “critical game information,” which must be maintained by casinos or other gaming machine establishment. Such data may be stored as simple text and/or graphics. In some cases, entire frames of video data may be captured for this purpose.
Examples of critical game transactions include, but are not limited to, reading credit information from a debit card, adding an amount of credit to a gaming machine, and accepting currency from a player. The critical game transaction may require the use of non-volatile memory either temporarily or more permanently. The non-volatile memory may store values temporarily as an intermediate step in the calculation of critical data. For example, when accepting currency from a player, a bill validator may determine the value of the currency as an integer number of dollars. This information may be stored into non-volatile memory temporarily, as an intermediate operational step, prior to determining the number of credits credited in the gaming machine. If the game comprises a 25 cent game, the number of credits calculated would correspond to forty credits if the player inserts a ten dollar bill. In this example, the critical data stored permanently in non-volatile memory may comprise the number of credits (forty), although the number of dollars (ten) would comprise an intermediate operational value in the calculation of the number of credits. As a consequence, the intermediate value ten may comprise data that is stored temporarily in non-volatile memory and is deleted upon the calculation of the critical data value forty which may be stored permanently in non-volatile memory.
Game history information may provide a record of outcomes for a number of rounds of play for a game in a gaming machine. For example, game history information may be used to verify the payouts of a gaming machine so that a verification of a winning jackpot may be performed before a payout is made if suspicious activity is recognized. Game history may also be used, for example, to audit the types of jackpots generated over a specified number of rounds of play or to provide evidence that a gaming machine has been tampered with. Hence, this type of information is critical to the casino or gaming machine owner.
Information that provides a running count or history of the credits that go in and out of the gaming machine may provide valuable accounting information. For example, a gaming machine's cumulative number of credits may be based on the bills or coins collected, the amount of credits generated from the insertion of a credit card, or bonus credits created by inputting a PIN (personal identification number). This type of data may be very useful to a gaming operator because it provides the revenue a gaming machine generates over a period of time.
Security information may provide information related to a tampering event on the gaming machine. Details of this information may include time of day, type of game, the amount wagered, the specific outcome, and any operational information, such as diagnostics related to the condition of the gaming machine when tampering occurred.
Player tracking information is also vital to providing valuable feedback regarding a player's preferences. A casino may track player information to provide the best and most desirable playing environment to the player. Whether it be type of game, denomination of game, length of play, amount played, or the like, these factors provide useful information to the gaming operator it can better attract and maintain game play from a player.
A few specific examples of critical data may include, for example, one or more of the following: (1) Main door/Drop door/Cash door openings and closings, (2) Bill insert message with the denomination of the bill, (3) Hopper tilt, (4) Bill jam, (5) Reel tilt, (6) Coin in and Coin out tilts, (7) Power loss, (8) Card insert, (9) Card removal, (10) Jackpot, (11) Abandoned card (12) querying the non-volatile memory for the current credit available on the gaming machine, (13) reading the credit information from a player's card, (14) adding an amount of credits to the gaming machine, (15) writing to a player's card via the card reader and the device drivers to deduct the amount added to gaming machine from the card, and (16) copying the new credit information to the non-volatile memory. Such information may be required, based on jurisdictional gaming regulations, to be stored for a certain period of time, e.g., 75 game plays after the information was accumulated.
As described above, non-volatile memory may be configured or designed to maintain the contents of its memory over time through the use of a battery as a power source, thereby allowing it to be independent of externally supplied power. As a result, non-volatile memory can continue to store data such as accumulated information as long as power is supplied.
The accumulative data to be saved may take the form of text, graphics, frames, video clips, etc. In the simplest case, it is merely textual data describing a game's state, history, statistics, etc. A more memory-intensive form of data storage stores frames (essentially bit maps of video still shots) for selected portions of the game presentation; e.g., frames associated with user inputs and presentation of game outcomes. Some of these frames may have embedded or associated data providing specific details such as state, statistics, etc. as described above. Yet another way to save relevant game play information is via a game play sequence that represents the game as it appeared originally. This involves presentation of a series of frames and associated events, including, for example, user interactive events. Such may be implemented using a series of critical or desired snapshots and/or screenshots, a movie or video clips of a game play, and/or other mechanisms representing the game play information. To implement this type of replay, it may be desirable to preserve essential state information about the game and then re-execute the game code using such state information.
During the course of game play, a gaming machine may undergo a number of different events, such as receiving currency, hopper tilt, reel tilt, protective tilt, power loss, player's card input, player's card removal, personal identification input, reel spin, multi-denomination change, jackpot tilt, and the like. During these transactional events, the temporary or permanent non-volatile memory or non-volatile storage requirements of the game or the gaming machine may change. Accordingly, memory space allocations are continuously monitored.
Gaming regulators, such as the Nevada gaming commission, require that gaming machines prohibit the writing of code, data and/or other gaming information to gaming machine disk drives by sources other than trusted memory sources which have been properly verified and authenticated. Because of such regulatory constraints, it has been conventional practice in the gaming industry to design and implement mechanisms for preserving critical data in the gaming machine's non-volatile memory without utilizing memory storage at the gaming machine's disk drive(s).
While the invention has been particularly shown and described with reference to specific embodiments thereof, it will be understood by those skilled in the art that changes in the form and details of the disclosed embodiments may be made without departing from the spirit or scope of the invention. However, it will be understood that embodiments in which such games are developed without such templates are within the scope of the invention. In addition, the host of a game development environment implemented according to the present invention does not necessarily need to be a gaming machine provider or manufacturer to remain within the scope of the invention. And as discussed above, any of a wide range of technologies may be employed to implement and provide access to such a game development environment.
Finally, although various advantages, aspects, and objects of the present invention have been discussed herein with reference to various embodiments, it will be understood that the scope of the invention should not be limited by reference to such advantages, aspects, and objects. Rather, the scope of the invention should be determined with reference to the appended claims.

Claims

1. A gaming machine comprising:

at least one processor;

at least one interface;

a hybrid non-volatile memory component having a byte-addressable non-volatile memory sub-component and a block-addressable non-volatile memory sub-component, the byte-addressable sub-component having at least three buffers and the block-addressable sub-component having at least one block, wherein critical gaming data is transferred from the byte-addressable sub-component to the block-addressable sub-component, where it is permanently stored; and

wherein a confirmation is sent from the block-addressable sub-component to the byte-addressable sub-component when the critical gaming data is permanently stored; and

wherein the critical gaming data is deleted from the byte-addressable sub-component when the confirmation is received.

2. A gaming machine as recited in claim 1 further comprising:

a hybrid non-volatile memory manager for controlling operations of the hybrid non-volatile memory component.

3. A gaming machine as recited in claim 1 wherein the block-addressable sub-component is a flash memory.

4. A gaming machine as recited in claim 1 wherein the size of a buffer in the byte-addressable sub-component depends on the size of a block in block-addressable sub-component.

5. A gaming machine as recited in claim 1 wherein critical gaming data is selected from the group consisting of game history information, security information, accounting information, player tracking information, wide area progressive information, game state information, game usage information, game transactional information, game meter information, bonus of game information, and player input information.

6. A gaming machine as recited in claim 1 wherein the hybrid non-volatile memory manager is an FPGA.

7. A gaming machine as recited in claim 6 wherein the hybrid non-volatile memory component and the memory manager are on the same chip in the gaming machine.

8. A gaming machine as recited in claim 7 wherein the chip is on a main processing board of the gaming machine.

9. A gaming machine as recited in claim 1 wherein the critical gaming data is transmitted to the hybrid non-volatile memory component from the at least one processor.

10. A method of storing gaming data in a hybrid memory component in a gaming machine, the gaming data required to be stored by a gaming operator pursuant to gaming regulations, the method comprising:

receiving gaming data at the hybrid memory component from one or more components in the gaming machine;

determining if a byte-addressable non-volatile memory buffer in the hybrid memory component is at maximum storage capacity with gaming data;

if it is at maximum storage capacity, writing the gaming data from the buffer to a block in the block-addressable non-volatile memory, wherein the gaming data continues to be stored in the buffer during the writing;

if it is not at maximum storage capacity, continuing to receive gaming data from the one or more components;

if the writing operation is complete, at the block-addressable non-volatile memory, checking if the gaming data has been stored persistently;

is if the gaming data has been stored persistently in the block-addressable non-volatile memory, sending a confirmation from the block-addressable non-volatile memory to the byte-addressable non-volatile memory buffer; and

deleting the gaming data from the buffer when the confirmation is received, thereby freeing the buffer to receive new data, such that gaming data is not lost if there is a disruption during the writing operation.

11. A method as recited in claim 10 further comprising checking the contents of the buffer to determine if the buffer is at maximum storage capacity.

12. A method as recited in claim 10 further comprising sending the confirmation to a non-volatile memory manager, wherein the non-volatile memory manager is a component in the hybrid memory component of the gaming machine.

13. A method as recited in claim 10 further comprising:

reading byte-addressable non-volatile memory administrative data to determine a next available buffer for receiving gaming data; and

changing a state of the buffer to indicate it is receiving gaming data.

14. A method as recited in claim 10 further comprising:

determining if the writing operation of gaming data from the buffer to the block is complete; and

if complete, changing a state of the buffer to indicate that it is at maximum storage capacity.

15. A method as recited in claim 10 further comprising:

determining if the writing operation was in progress between a byte-addressable buffer and the block in block-addressable non-volatile memory during a disruption in the gaming machine operations;

if gaming data was being written to the block during the disruption, erasing the data from the block upon resumption of gaming machine operations; and

re-writing the gaming data from the byte-addressable buffer to the block.

16. A method as recited in claim 15 further comprising:

reading administrative data in the byte-addressable non-volatile memory to determine which sectors in the block should be erased.

17. A method as recited in claim 15 further comprising checking a state variable of the block-addressable buffer.

18. A method as recited in claim 10 wherein the gaming data is selected from the group consisting of game history information, security information, accounting information, player tracking information, wide area progressive information and game state information, game usage information, game transactional information, game meter information, bonus of game information, and player input information.

19. A gaming device capable of storing required gaming data pursuant to wager gaming regulations comprising:

a master gaming controller;

a hybrid non-volatile memory component having a byte-addressable memory, a block-addressable memory, and an FPGA; and

a memory storing computer instructions for:

receiving the required gaming data at the hybrid memory component from the master gaming controller;

determining if a byte-addressable non-volatile memory buffer in the hybrid memory component is at maximum storage capacity with required gaming data;

if it is at maximum storage capacity, writing the required gaming data from the buffer to a block in the block-addressable memory, wherein the required gaming data continues to be stored in the buffer during the writing;

if it is not at maximum storage capacity, continuing to receive required gaming data from the master gaming controller;

if the writing operation is complete, at the block-addressable memory, checking if the required gaming data has been journaled persistently;

if the required gaming data has been journaled persistently in the block-addressable memory, sending a confirmation from the block-addressable memory to the byte-addressable memory buffer; and

deleting the required gaming data from the buffer when the confirmation is received, thereby freeing the buffer to receive new required gaming data, such that required gaming data being written is not lost if there is a disruption in the gaming device operations during the writing operation, and

wherein the gaming device is able to store required gaming data pursuant to gaming regulations using a combination of lower-cost non-volatile memory for long-term persistent journaling and higher-cost memory for intermediate buffering of the required gaming data.

20. A gaming device as recited in claim 19 wherein the memory further comprises computer code for:

determining if the writing operation of required gaming data from the buffer to the block is complete; and

21. A gaming device as recited in claim 19 wherein the memory further comprises computer code for:

determining if the writing operation was in progress between a byte-addressable buffer and the block in block-addressable memory during a disruption in the gaming machine operations;

if the required gaming data was being written to the block during the disruption, erasing the required data from the block upon resumption of gaming machine operations; and

re-writing the required gaming data from the byte-addressable buffer to the block.

22. A gaming device as recited in claim 19 wherein the required gaming data is selected from the group consisting of game history information, security information, accounting information, player tracking information, wide area progressive information, game state information, game usage information, game transactional information, game meter information, bonus of game information, and player input information.