Patent Publication Number: US-2018054359-A1

Title: Network attached reconfigurable computing device

Description:
BACKGROUND 
     The invention relates to a reconfigurable computing device that can be attached to a network. 
     In recent years, Field Programmable Gate Array (FPGA) technology continued to grow in importance as one of multiple programmable off-the-shelf accelerator technologies that can be used to improve performance and optimize power for selected application domains. As part of ongoing FPGA developments, the concept of dynamic partial reconfiguration support is gaining attention. The latter allows to reconfigure only selected parts of an FPGA during runtime. 
     Reconfigurable computing devices, such as FPGAs, are usually used as a co-processor tightly coupled with a server, e.g. over the PCIe bus. This tight-coupling however inhibits the usage of FPGAs in a scalable and a flexible manner. 
     Accordingly, there is a need for new system architectures for reconfigurable computing devices. 
     SUMMARY 
     According to a first aspect, the invention is embodied as a reconfigurable computing device. The device comprises an application layer adapted to run a plurality of applications, a configuration layer adapted to configure the applications and a network layer adapted to provide access to a network for the configuration layer and the application layer. The network layer and the configuration layer are configured as static partitions in a static region of the device. The static partitions and the static region are configured only upon booting the device. The applications are configured as dynamic partitions in a dynamic region of the device and the dynamic partitions and the dynamic region are reconfigurable during operation of the device. 
     According to another aspect a computer implemented method for operating a reconfigurable computing device is provided. The reconfigurable computing device comprises an application layer, a configuration layer, a network layer and a memory unit. The method comprises booting the device from a static bit stream stored in the memory unit. Thereby the configuration layer and the network layer are configured as static partition in a static region of the device. The method further comprises configuring, by the configuration layer, applications as dynamic partitions in a dynamic region of the device and running, by the application layer, a plurality of applications. The method further comprises providing, by the network layer, access to a network for the configuration layer and the application layer. 
     Embodiments of the invention will be described in more detail below, by way of illustrative and non-limiting examples, with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  depicts a cloud computing node according to an embodiment of the present invention; 
         FIG. 2  depicts a cloud computing environment according to an embodiment of the present invention; 
         FIG. 3  depicts abstraction model layers according to an embodiment of the present invention; 
         FIG. 4  illustrates a reconfigurable computing device according to an embodiment of the invention; 
         FIG. 5  illustrates in an exemplary way the storage of a static bit stream in a reconfigurable computing device according to an embodiment of the invention; 
         FIG. 6  shows a system according to an embodiment of the invention; and 
         FIG. 7  shows method steps of a computer implemented method for operating a reconfigurable computing device according to an embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     In reference to  FIGS. 1-7 , some general aspects and terms of embodiments of the invention are described. 
     In the context of this description, the following conventions, terms and/or expressions may be used: 
     The term “field programmable gate array” (FPGA) may denote an integrated hardware circuit designed to be configured for one or more computing tasks by a system designer after manufacturing—hence “field-programmable”. The one or more FPGA configurations may be generally specified using a hardware description language (HDL) and may have large resources of logic gates and RAM blocks to implement complex digital computations. 
     A reconfigurable computing device according to embodiments of the invention may be implemented in particular for applications requiring calculations that are highly repetitive, like, e.g., in Fast Fourier Transformation (FFT) calculations or matrix-vector multiplications. This type of calculations are based on repetitive add/multiply operations. 
     The term bitstream shall denote “configuration data” that shall be used to configure one or more partitions of a reconfigurable computing device, in particular a FPGA, for a specific function or computing task. The configuration data may be implemented as a horizontal micro-code vector for the setting of multiplexers defining the functionality of the partitions of the reconfigurable computing device. Different bitstreams and different configuration data respectively may result in different functionalities of the one or more partitions of the reconfigurable computing device. It should be noted that the term bitstream shall encompass “serial bitstreams” that are loaded into a reconfigurable device in a serial manner, but also “parallel bitstreams” that are loaded into a reconfigurable device according to parallel loading methods such as byte-parallel loading. 
     The term “operand data” may denote data that shall be processed by a reconfigurable computing device according to embodiments of the invention. 
     The term “control information” may denote control information or control data that shall be used to control the operation of the device. 
     Embodiments of the invention propose an architecture of a reconfigurable computing device which provides a direct network attachment for applications running in an application layer of the device. 
     According to embodiments of the invention reconfigurable computing devices can be decoupled from any host server. The reconfigurable computing device according to embodiments of the invention can operate as standalone device that can be operated without an external controller. More particularly, the device may be operated as independent self-managed device. The device may have only a single point of attachment to the network and according to embodiments only one physical network connection/network cable is needed to connect the reconfigurable computing device. 
     It is to be understood that although this disclosure includes a detailed description on cloud computing, implementation of the teachings recited herein are not limited to a cloud computing environment. Rather, embodiments of the present invention are capable of being implemented in conjunction with any other type of computing environment now known or later developed. 
     Cloud computing is a model of service delivery for enabling convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, network bandwidth, servers, processing, memory, storage, applications, virtual machines, and services) that can be rapidly provisioned and released with minimal management effort or interaction with a provider of the service. This cloud model may include at least five characteristics, at least three service models, and at least four deployment models. 
     Characteristics are as follows: 
     On-demand self-service: a cloud consumer can unilaterally provision computing capabilities, such as server time and network storage, as needed automatically without requiring human interaction with the service&#39;s provider. 
     Broad network access: capabilities are available over a network and accessed through standard mechanisms that promote use by heterogeneous thin or thick client platforms (e.g., mobile phones, laptops, and PDAs). 
     Resource pooling: the provider&#39;s computing resources are pooled to serve multiple consumers using a multi-tenant model, with different physical and virtual resources dynamically assigned and reassigned according to demand. There is a sense of location independence in that the consumer generally has no control or knowledge over the exact location of the provided resources but may be able to specify location at a higher level of abstraction (e.g., country, state, or datacenter). 
     Rapid elasticity: capabilities can be rapidly and elastically provisioned, in some cases automatically, to quickly scale out and rapidly released to quickly scale in. To the consumer, the capabilities available for provisioning often appear to be unlimited and can be purchased in any quantity at any time. 
     Measured service: cloud systems automatically control and optimize resource use by leveraging a metering capability at some level of abstraction appropriate to the type of service (e.g., storage, processing, bandwidth, and active user accounts). Resource usage can be monitored, controlled, and reported, providing transparency for both the provider and consumer of the utilized service. 
     Service Models are as follows: 
     Software as a Service (SaaS): the capability provided to the consumer is to use the provider&#39;s applications running on a cloud infrastructure. The applications are accessible from various client devices through a thin client interface such as a web browser (e.g., web-based e-mail). The consumer does not manage or control the underlying cloud infrastructure including network, servers, operating systems, storage, or even individual application capabilities, with the possible exception of limited user-specific application configuration settings. 
     Platform as a Service (PaaS): the capability provided to the consumer is to deploy onto the cloud infrastructure consumer-created or acquired applications created using programming languages and tools supported by the provider. The consumer does not manage or control the underlying cloud infrastructure including networks, servers, operating systems, or storage, but has control over the deployed applications and possibly application hosting environment configurations. 
     Infrastructure as a Service (IaaS): the capability provided to the consumer is to provision processing, storage, networks, and other fundamental computing resources where the consumer is able to deploy and run arbitrary software, which can include operating systems and applications. The consumer does not manage or control the underlying cloud infrastructure but has control over operating systems, storage, deployed applications, and possibly limited control of select networking components (e.g., host firewalls). 
     Deployment Models are as follows: 
     Private cloud: the cloud infrastructure is operated solely for an organization. It may be managed by the organization or a third party and may exist on-premises or off-premises. 
     Community cloud: the cloud infrastructure is shared by several organizations and supports a specific community that has shared concerns (e.g., mission, security requirements, policy, and compliance considerations). It may be managed by the organizations or a third party and may exist on-premises or off-premises. 
     Public cloud: the cloud infrastructure is made available to the general public or a large industry group and is owned by an organization selling cloud services. 
     Hybrid cloud: the cloud infrastructure is a composition of two or more clouds (private, community, or public) that remain unique entities but are bound together by standardized or proprietary technology that enables data and application portability (e.g., cloud bursting for load-balancing between clouds). 
     A cloud computing environment is service oriented with a focus on statelessness, low coupling, modularity, and semantic interoperability. At the heart of cloud computing is an infrastructure that includes a network of interconnected nodes. 
     Referring now to  FIG. 1 , a schematic of an example of a cloud computing node is shown. Cloud computing node  10  is only one example of a suitable cloud computing node and is not intended to suggest any limitation as to the scope of use or functionality of embodiments of the invention described herein. Regardless, cloud computing node  10  is capable of being implemented and/or performing any of the functionality set forth hereinabove. 
     In cloud computing node  10  there is a server  12 , which is operational with numerous other general purpose or special purpose computing system environments or configurations. Examples of well-known computing systems, environments, and/or configurations that may be suitable for use with server  12  include, but are not limited to, personal computer systems, server computer systems, thin clients, thick clients, hand-held or laptop devices, multiprocessor systems, microprocessor-based systems, set top boxes, programmable consumer electronics, network PCs, minicomputer systems, mainframe computer systems, and distributed cloud computing environments that include any of the above systems or devices, and the like. 
     Server  12  may be described in the general context of computer system-executable instructions, such as program modules, being executed by a computer system. Generally, program modules may include routines, programs, objects, components, logic, data structures, and so on that perform particular tasks or implement particular abstract data types. Server  12  may be practiced in distributed cloud computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed cloud computing environment, program modules may be located in both local and remote computer system storage media including memory storage devices. 
     As shown in  FIG. 1 , server  12  in cloud computing node  10  is shown in the form of a general-purpose computing device. The components of server  12  may include, but are not limited to, one or more processors or processing units  16 , a system memory  28 , and a bus  18  that couples various system components including system memory  28  to processor  16 . 
     Bus  18  represents one or more of any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, and a processor or local bus using any of a variety of bus architectures. By way of example, and not limitation, such architectures include Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnect (PCI) bus. 
     Server  12  typically includes a variety of computer system readable media. Such media may be any available media that is accessible by server  12 , and it includes both volatile and non-volatile media, removable and non-removable media. 
     System memory  28  can include computer system readable media in the form of volatile memory, such as random access memory (RAM)  30  and/or cache memory  32 . Server  12  may further include other removable/non-removable, volatile/non-volatile computer system storage media. By way of example only, storage system  34  can be provided for reading from and writing to a non-removable, non-volatile magnetic media (not shown and typically called a “hard drive”). Although not shown, a magnetic disk drive for reading from and writing to a removable, non-volatile magnetic disk (e.g., a “floppy disk”), and an optical disk drive for reading from or writing to a removable, non-volatile optical disk such as a CD-ROM, DVD-ROM or other optical media can be provided. In such instances, each can be connected to bus  18  by one or more data media interfaces. As will be further depicted and described below, memory  28  may include at least one program product having a set (e.g., at least one) of program modules that are configured to carry out the functions of embodiments of the invention. 
     Program/utility  40 , having a set (at least one) of program modules  42 , may be stored in memory  28  by way of example, and not limitation, as well as an operating system, one or more application programs, other program modules, and program data. Each of the operating system, one or more application programs, other program modules, and program data or some combination thereof, may include an implementation of a networking environment. Program modules  42  generally carry out the functions and/or methodologies of embodiments of the invention as described herein. 
     Server  12  may also communicate with one or more external devices  14  such as a keyboard, a pointing device, a display  24 , etc.; one or more devices that enable a user to interact with server  12 ; and/or any devices (e.g., network card, modem, etc.) that enable server  12  to communicate with one or more other computing devices. Such communication can occur via Input/Output (I/O) interfaces  22 . Still yet, server  12  can communicate with one or more networks such as a local area network (LAN), a general wide area network (WAN), and/or a public network (e.g., the Internet) via network adapter  20 . As depicted, network adapter  20  communicates with the other components of server  12  via bus  18 . It should be understood that although not shown, other hardware and/or software components could be used in conjunction with server  12 . Examples, include, but are not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data archival storage systems, etc. 
     Referring now to  FIG. 2 , illustrative cloud computing environment  50  is depicted. As shown, cloud computing environment  50  includes one or more cloud computing nodes  10  with which local user devices used by cloud consumers, such as, for example, personal digital assistant (PDA) or cellular telephone  54 A, desktop computer  54 B, laptop computer  54 C, and/or automobile computer system  54 N may communicate. The user devices  54 A,  54 B,  54 C and  54 N may in the following be also generally referred to as user devices  54 . The user devices  54  may belong to the same user or a user group. User devices  54  that belong to the same user or a user group are referred to as set  55  of user devices  54 . Nodes  10  may communicate with one another. They may be grouped (not shown) physically or virtually, in one or more networks, such as Private, Community, Public, or Hybrid clouds as described hereinabove, or a combination thereof. This allows cloud computing environment  50  to offer infrastructure, platforms and/or software as services for which a cloud consumer does not need to maintain resources on a local computing device. It is understood that the types of computing devices  54 A-N shown in  FIG. 1  are intended to be illustrative only and that computing nodes  10  and cloud computing environment  50  can communicate with any type of computerized device over any type of network and/or network addressable connection (e.g., using a web browser). 
     Referring now to  FIG. 3 , a set of functional abstraction layers provided by cloud computing environment  50  ( FIG. 2 ) is shown. It should be understood in advance that the components, layers, and functions shown in  FIG. 3  are intended to be illustrative only and embodiments of the invention are not limited thereto. As depicted, the following layers and corresponding functions are provided: 
     Hardware and software layer  60  includes hardware and software components. Examples of hardware components include: mainframes  61 ; RISC (Reduced Instruction Set Computer) architecture based servers  62 ; servers  63 ; blade servers  64 ; storage devices  65 ; and networks and networking components  66 . In some embodiments, software components include network application server software  67  and database software  68 . 
     Virtualization layer  70  provides an abstraction layer from which the following examples of virtual entities may be provided: virtual servers  71 ; virtual storage  72 ; virtual networks  73 , including virtual private networks; virtual applications and operating systems  74 ; and virtual clients  75 . 
     In one example, management layer  80  may provide the functions described below. Resource provisioning  81  provides dynamic procurement of computing resources and other resources that are utilized to perform tasks within the cloud computing environment. Metering and Pricing  82  provide cost tracking as resources are utilized within the cloud computing environment, and billing or invoicing for consumption of these resources. In one example, these resources may include application software licenses. Security provides identity verification for cloud consumers and tasks, as well as protection for data and other resources. User portal  83  provides access to the cloud computing environment for consumers and system administrators. Service level management  84  provides cloud computing resource allocation and management such that required service levels are met. Service Level Agreement (SLA) planning and fulfillment  85  provide pre-arrangement for, and procurement of, cloud computing resources for which a future requirement is anticipated in accordance with an SLA. 
     Workloads layer  90  provides examples of functionality for which the cloud computing environment may be utilized. Examples of workloads and functions which may be provided from this layer include: mapping and navigation  91 ; software development and lifecycle management  92 ; virtual classroom education delivery  93 ; data analytics processing  94 ; transaction processing  95 ; and repetitive computing tasks such as FFT calculations  96  that are in particular suitable to be performed by reconfigurable computing devices such as FPGAs. 
       FIG. 4  illustrates a reconfigurable computing device  400  according to an embodiment of the invention. The reconfigurable computing device  400  is embodied as Field Programmable Gate Array (FPGA) and comprises an FPGA-chip  401  and a memory unit  402 . The FPGA chip  401  and the memory unit  402  are arranged on a common printed circuit board (PCB)  403 . The memory unit  402  may be in particular embodied as Flash-memory. 
     The FPGA-chip  401  of the reconfigurable computing device  400  comprises an application layer  404  adapted to run a plurality of applications App i . The applications App i  may be e.g. applications requiring calculations that are highly repetitive, like, e.g., in Fast Fourier Transformation (FFT) calculations or matrix-vector multiplications. The FPGA-chip  401  of the device  400  comprises further a configuration layer  405  that is adapted to configure or program the applications App i . into the application layer  404 . It should be noted that the terms “configuring” and “programming” are generally used in an interchangeable way. The FPGA-chip  401  comprises further a network layer  406  adapted to provide access to a network  407  for the configuration layer  405  and the application layer  406 . The FPGA-chip  401  comprises an integrated Input/Output (I/O)-circuit  408  that provides standard hardware circuitry for providing an I/O interface to the network  407 . The I/O circuit  408  may encompass e.g. the user pins provided by the FPGA-chip  401 . 
     The network layer  406  is configured as static partition  406   a  and the configuration layer  405  is configured as static partition  405   a . The static partitions  405   a  and  406   a  establish a static region  410  of the device  400 . The static partitions  406   a  and  405   a  and correspondingly the static region  410  are configured only once upon booting the device  400 . After the static partitions  405   a  and  406   a  have been configured, they remain unchanged during operation of the device  400  at least until the next booting of the device  400 . Once configured upon booting, the configuration layer  405  and the network layer  406  provide predefined functionalities for the device  400  which will be explained below in more detail. 
     The applications App i  are configured as dynamic partitions in a dynamic region  411  of the device  400 . In the exemplary embodiment of  FIG. 4 , a dynamic partition  412  has been configured for an application App 1  and a dynamic partition  413  has been configured for an application App 2  The dynamic region  411  and the dynamic partitions  412 ,  413  are reconfigurable during operation of the device  400 , hence dynamic partitions and dynamic region. More particularly, new applications App i  may be programmed into the dynamic region  411  during operation of the device  400 . Furthermore, applications App i  that have already been configured in the dynamic region  411  may be removed from the dynamic region  411  during runtime and replaced with new applications App i . 
     The memory unit  402  is provided for storing a static bit stream  415  comprising configuration data to configure the configuration layer  405  and the network layer  406 . The static bit stream  415  serves as boot file or boot region for the device  400 . More particularly, when the device  400  is booted, e.g. by turning on a power supply for the device  400 , the device  400  boots from the static bit stream  415 . Thereby the configuration layer  405  and the network layer  406  are configured and programmed respectively in the static region  410  of the device  400 . In order to make the device  400  accessible to the network  407 , the device  400  may get through the network layer  406  an Internet Protocol (IP address) from a DHCP-server connected to the network  407 . In order to request the IP address, the device  400  sends its MAC address to the DHCP-server. The MAC address of the device  400  may be stored e.g. in a small read only memory of the device  400 , e.g. during manufacturing of the device  400 . According to another embodiment the static bit stream may comprise the MAC-address of the device  400 . 
     The memory unit  402  is further provided for storing application bit streams  416  in the memory unit  402 . The application bit streams  416  comprise configuration data to configure one or more applications App i . According to some embodiments one or more application bit streams  416  may be stored e.g. permanently as standard application bit streams in the memory unit  402 . These permanently stored application bit streams  416  may store e.g. configuration data for applications that are often or regularly used. According to other embodiments application bit streams may be received during the operation of the device  400  from the network  407  via the network layer  406 . The application bit streams received from the network  407  may be either configured directly by the configuration layer  405  into the application layer  404  or they may be first stored in the memory unit  402  and then programmed from the memory unit  402  by the configuration layer  405  into the application layer  404 . In this respect the configuration layer  405  serves as control unit/controller for controlling the programming of the respective application bit stream into the application layer  404 . To enable network access to the respective application App i , the configuration layer  405  also configures address information for the applications App i  into the network layer  406 . More particularly, the configuration layer  405  configures according to embodiments an Internet Protocol (IP) address and a Media Access Control (MAC) address for the applications App i  into the network layer  406 . 
     As illustrated in  FIG. 4  with arrows, as a result of the configuration the device  400  comprises a data path  420  between the network layer  406  and the application layer  404 . The data path  420  is provided for transferring operand data between the network layer  406  and the application layer  404 . The operand data may be e.g. data that has been received via the network layer  406  from the network  407  and that shall be processed by one of the applications App i  of the reconfigurable computing device  400 . As an example, if an application App i  is an application for performing a FFT-calculation, the operand data is the input data for the FFT calculation received from the network  407 . The operand data may be e.g. sent from a client computer  430  or a server computer  431  coupled to the network  407 . This enables the client computer  430  and/or the server computer  431  to use the processing resources of the device  400 . 
     Furthermore, the application layer  404  provides a control path  421  between the network layer  406  and the configuration layer  405 . The control path  421  is provided for transferring control information between the network layer  406  and the configuration layer  405 . The control information is information or data that is used to control the operation of the device  400  and in particular to program or configure applications App i  into the application layer  404 . The control information also encompasses application bitstreams that have been received via the network layer  406  from the network  407  and that shall be programmed into the application layer  404  and/or stored in the memory unit  402 . 
     In addition, a shared control/data path  422  is provided, via the integrated I/O circuit  408 , between the network layer  406  and the network  407 . The shared control/data path  422  is provided for transferring operand data and control information between the network layer  406  and the network  407 . This shared control/data path  422  combines the operand data transmitted between the network layer  406  and the application layer  404  via the data path  420  and the control information transmitted between the network layer  406  and the configuration layer  405  via the control path  421 . The shared control/data path  422  enables the device  400  to communicate with the network  407  via a single physical data connection  423  provided between the integrated I/O circuit  408  and the network  407 . The single physical data connection  423  may be e.g. a single cable such as an Ethernet-cable that is plugged into a connector of the integrated I/O circuit  408 . 
     The device  400  may be used to provide computing services in a cloud environment via the network  407  to a plurality of client computers  430  and/or server computers  431  connected to the network  407 . 
       FIG. 5  illustrates in an exemplary way the storage of a static bit stream in a reconfigurable computing device  500  according to an embodiment of the invention. The reconfigurable computing device  500  is also embodied as Field Programmable Gate Array (FPGA) and comprises an FPGA-chip  501  and a memory unit  502  that is embodied as flash-memory. The FPGA chip  501  and the memory unit  502  are arranged on a common printed circuit board (PCB)  503 , also denoted as FPGA board  503 . The FPGA board  503  comprises a JTAG-port  504  that is embodied according to the Joint Test Action Group (JTAG) standard. The JTAG-port  504  provides connection pins for external devices  505  such as client computers or server computers to connect with the FPGA board  503 . The FPGA-chip  501  comprises a JTAG-interface  506  to connect the FPGA-chip  501  with the he JTAG-port  504  and a flash-interface  507  to connect the FPGA-chip  501  with the memory unit  502 . A path  510  for storing a static bit stream in the memory unit  502  is illustrated with dotted lines. More particularly, the static bit stream is sent from the external device  505  to the JTAG-port  504 , then to the JTAG-interface  506  and via the flash-interface  507  to the memory unit  502 . 
       FIG. 6  shows a system  600  according to an embodiment of the invention. The system  600  comprises as reconfigurable computing devices a plurality of FPGA boards  601 . The FPGA boards  601  may be e.g. embodied like the PCBs  403  as described with reference to  FIG. 4 . The system  600  comprises furthermore a plurality of server computers  602  and a plurality of client computers  603 . The server computers  602 , the client computers  603  and the FPGA boards  601  are all connected to a network  604  and may communicate with each other over the network  604 . In order to facilitate the communication between the server computers  602 , the client computers  603  and the FPGA boards  601 , a central network switch  605  is provided. The central network switch  605  is controlled by a resource manager  606  which serves as resource manager for the server computers  602 , the client computers  603  and the FPGA boards  601 . The resource manager  606  is in particular configured to manage the connections between the server computers  602 , the client computers  603  and the FPGA boards  601  and to arrange IP-addresses and MAC-addresses for them. The IP-addresses and MAC-addresses provided by the resource manager  606  may be in particular virtual addresses. Accordingly the IP-addresses and MAC-addresses that the configuration layer configures into the network layer for the respective applications that run in the application layer may also be embodied as virtual IP-addresses and virtual MAC-addresses. More particularly, the configuration layer of the respective FPGA-board  601  may receive a virtual IP-address and a virtual MAC-address for a new application that shall be configured from the resource manager  606  and configure this received virtual IP-address and MAC-address into the network layer  406 . 
     The server computers  602  may be embodied e.g. as the server  12  as described with reference to  FIG. 1 . According to embodiments the server computers  602  may establish a cloud computing node for the client computers  603 . According to such a cloud embodiment the server computers  602  may offer computing services in a cloud environment to the client computers  603 . According to such a cloud embodiment, the server computers  602  may utilize the FPGA-boards  601  to perform special and in particular highly-repetitive computing tasks such as FFT-computations or matrix-vector multiplications. 
       FIG. 7  shows method steps of a computer implemented method for operating a reconfigurable computing device, e.g. the device  400  as described with reference to  FIG. 4 . 
     At a step  700 , the method is started. 
     At a step  705 , a static bit stream is generated. The static bit stream comprises configuration data for configuring the configuration layer  405  and the network layer  406 . 
     At a step  710 , the generated static bit stream is stored in the memory unit  402  of the device  400 . 
     The steps  710  and  715  may be e.g. performed by the provider of the devices  400 . By storing the static bit stream in the memory unit  402  of the device, the device  400  has been prepared/initialized to act as standalone reconfigurable device that can be attached to a network. 
     At a step  720 , the device  400  is booted from the static bit stream that is stored in the memory unit  402 . During the booting step  420 , the configuration layer  405  and the network layer  406  are configured as a static partition in the static region  410  of the device  400 . 
     At a step  725 , the device  400  gets an IP-address, e.g. from a DHCP-server, through the network layer  406 . Accordingly the network layer  406  provides then access to the network  407  for the configuration layer  405  and the application layer  404 . This allows external devices of the network  407 , e.g. the server computers  431  or the client computers  430 , to communicate with the device  400  and to use the device  400  to perform computing tasks. 
     At a step  730 , it is checked whether a new application shall be configured. Otherwise the method stops in a step  735  for the time being. If a new application shall be configured, the configuration layer receives in a step  740  an application bit stream via the network layer  406  from the network  407 . In a step  745  the configuration layer  405  stores the received application bit stream in the memory unit  402 . At a step  750 , the configuration layer  405  configures or programs the application bit stream into the dynamic region  411  of the device  400 . For this, the configuration layer  405  may request the memory unit  402  to program the application bit stream into the dynamic region  411 . According to other embodiments the configuration layer  405  may configure the received application bit stream directly into the dynamic region  411  of the device  400 . 
     At a step  755 , the configuration layer  405  configures address information for the respective application into the network layer  406 . This may include configuring an Internet Protocol (IP) address and a Media Access Control (MAC) address for the application into the network layer  406 . The IP-address and the MAC-address may be in particular virtual addresses that the configuration layer  405  receives from the resource manager  606  as described with reference to  FIG. 6 . 
     As a result, the respective application has been fully configured in the application layer  404  and can be accessed via the network layer  406  from devices connected to the network  407 . Accordingly in a step  760  the newly configured application is running in the application layer  404 . 
     During operation of the device  400  other new applications may be configured at runtime in the dynamic region  411 . For this, the steps  730 - 760  as described above may be repeated. 
     The descriptions of the various embodiments of the present invention have been presented for purposes of illustration, but are not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein was chosen to best explain the principles of the embodiments, the practical application or technical improvement over technologies found in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.