Browse Prior Art Database

Method for remote register model emulation

IP.com Disclosure Number: IPCOM000012449D
Publication Date: 2003-May-07
Document File: 3 page(s) / 127K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for emulating the remote hardware devices as devices directly attached to a local system by mirroring the remote device's register set and synchronizing the states between device and it's mirror. Benefits include improved functionality and improved performance.

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Method for remote register model emulation

Disclosed is a method for emulating the remote hardware devices as devices directly attached to a local system by mirroring the remote device’s register set and synchronizing the states between device and its mirror. Benefits include improved functionality and improved performance.

Background

        � � � � � In many conventional network applications, a standard or nonstandard network is used to bridge or extend interfaces that were not originally designed for networking. A simple example would be making the interface of an IEEE1394 controller device remote over the fiber optic or IP network to extend the maximum distance supported by the interface. Let us consider camcoder connected to PC via IP network and IEEE1394 interface.

        � � � � � A conventional solution would be to use the CPU in the remote network node to initialize and control the operation of remote host controllers (see Figure 1). The data from them is first buffered, then encapsulated in a suitable network protocol (IP in this case), and finally transferred to the network interface in the host PC. The network interface driver unencapsulates the data, and then sends it to the intermediate drivers, which present the data to the application through a dedicated application programming interface (API). If a non-standard hardware is used, a new software stack between the hardware and API is required, so that the application still can work with the same API. This approach requires a lot of new software on both ends of the link, and will not work if some of the applications attempt to access the hardware directly, bypassing the API.

        � � � � � It may be desirable to fully emulate devices the Ethernet controller, open host common interface for 1394 interface (OHCI), or the universal host common interface (UHCI) for the USB controller, by mirroring the register set of remote devices like such controllers. Because the locally mirrored register sets are identical to the original controllers in the remote node, the unmodified standard drivers and plug-and-play software can be used to support the remote devices, and software may also bypass API if desired.

General description

        � � � � � The disclosed method is a universal remote register model emulation by Hardware Register Mirroring. A special register file in the network adapter is used to mirror the register model of the remote devices. The network interface in the PC exposes “simulated” registers as if it were more than one device installed in the PC: network adapter plus one or more remote devices.

Advantages

        � � � � � The disclosed method provides advantages, including:

·        � � � Improved functionality due to efficiently modeling remote registers and tracking states changes

·        � � � Improved functionality and universality due to implementing the dual port register file as mirror

·        � � � Improved functionality due to implementing mirroring of the interrupt registers block

·        � � � Improved functiona...