Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
114 words
An interface device for transferring data processing commands and associated data between a user's host system (20) having a main memory (32) and an external data processing system (24), comprising: means (35) for representing said data processing commands and associated data as respective command/pointer packets comprising said data processing commands and virtual pointers to said associated data in virtual memory space of the user's host system (20); means (222) for translating said virtual pointers to physical pointers which identify physical addresses within said main memory (32) at which said associated data is located; and means (223) for reading and writing said associated data from and to said main memory (32) at said physical addresses.
Claim 2
Dependent Claim
109 words
An interface device for transferring graphics commands and graphics primitives between a user's host system (20) having a main memory (32) and a graphics subsystem (24), comprising: means (35) for representing said graphics commands and graphics primitives as respective command/pointer packets comprising said graphics commands and virtual pointers to said graphics primitives in virtual memory space of the user's host system (20); means (222) for translating said virtual pointers to physical pointers which identify physical addresses within said main memory (32) at which said graphics primitives are located; and means (223) for reading and writing said graphics primitives from and to said main memory (32) at said physical addresses.
Claim 3
Dependent Claim
71 words
A device as in claim 2, wherein said representing means comprises a user applications program (202, 203) operating on said user's host system (20) and said translating means comprises a DMA processor (222) having access to at least one shadow page table updated by a processor driven operating system (201) of the user's host system (20), said at least one shadow page table containing physical pointers corresponding to said virtual pointers.
Claim 4
Dependent Claim
28 words
A device as in claim 3, wherein said DMA processor (222) has a user privileged shadow page table for each user controlled process of said host system (20).
Claim 5
Dependent Claim
28 words
A device as in claim 4, wherein said DMA processor (222) includes a translation lookaside buffer for storing the addresses of recent accesses to said shadow page table.
Claim 6
Dependent Claim
80 words
A device as in claim 5, further comprising additional data storage means (38) for storing data, said DMA processor (222) interrupting said processor driven operating system (201) so that said processor driven operating system (201) can operate a fault algorithm for locating and swapping said graphics primitives between said additional data storage means (38) and said main memory (32) when said reading and writing means (223) receives an indication that said graphics primitives are not in said main memory (32).
Claim 7
Dependent Claim
38 words
A device as in claim 6, wherein entries in said shadow page table are updated by said processor driven operating system (201) in response to said indication that said graphics primitives are not in said main memory (32).
Claim 8
Dependent Claim
31 words
A device as in claim 7, wherein entries in said shadow page table are created by said processor driven operating system (201) in response to commands from said DMA processor (222).
Claim 9
Independent Claim
114 words
A method for providing direct memory access by an external data processing system (24) to data stored in a main memory (32) of the user's host system (20) in response to a user's data processing command, comprising the steps of: representing said user's data processing command and associated data as a command/pointer packet including a virtual pointer to said associated data in virtual memory space of said user in said user's host system (20); translating said virtual pointer to a physical pointer which identifies a physical address within said main memory (32) at which said associated data is located; and accessing said main memory (32) at the physical address identified by said physical pointer.