Nvidia Corporation

Pinnacle Peak Holding Corporation

Rugged Solutions America, LLC

Pinnacle Peak Holdings Corporation

James P Roberts

David Brian Glasco

Patrick Rene Marchand

Peter B Holmqvist

George R Lynch

Karan Mehra

John H Edmondson

Steven E Molnar

Cass Watson Everitt

James Chaput

Jason Gossiaux

David Fettig

Emmett Michael Kilgariff

David Kirk McAllister

Steve B Hall

Samuel W Grove

Disclosed herein are systems and methods for self-formation and self-management of full-duplex communication networks. In an embodiment, a communication device determines whether there is an available self-assignable device-data time slot. If there is, the device selects an available time slot for outbound transmissions, updates its network-status table to associate the selected time slot with a device identifier of the communication device, and transmits outbound device data during the selected time slot of at least one ensuing frame. The device also, during each of a plurality of ensuing frames, makes a determination as to whether to transmit a maintenance packet during a shared time slot of the current frame. If the determination is made in the affirmative, the device transmits such a packet during that shared time slot. Each such packet contains at least a subset of the network-status table.

Systems and methods for self-formation and self-management of full-duplex communication networks

One embodiment of the present invention sets forth a technique for increasing available storage space within compressed blocks of memory attached to data processing chips, without requiring a proportional increase in on-chip compression status bits. A compression status bit cache provides on-chip availability of compression status bits used to determine how many bits are needed to access a potentially compressed block of memory. A backing store residing in a reserved region of attached memory provides storage for a complete set of compression status bits used to represent compression status of an arbitrarily large number of blocks residing in attached memory. Physical address remapping ('swizzling') used to distribute memory access patterns over a plurality of physical memory devices is partially replicated by the compression status bit cache to efficiently integrate allocation and access of the backing store data with other user data.

Compression status bit cache and backing store

The present disclosure relates to a system and method of cancelling feedback in a vehicle communications system. The system and method may adjust a phase and a polarity of the microphone signal to produce an inverted microphone signal having a shifted phase. A speaker signal may be summed with the inverted microphone signal to cancel out at least a portion of a microphone signal component of the speaker signal.

Feedback cancellation for vehicle communications system

A method for cleaning dirty data in an intermediate cache is disclosed. A dirty data notification, including a memory address and a data class, is transmitted by a level 2 (L2) cache to frame buffer logic when dirty data is stored in the L2 cache. The data classes may include evict first, evict normal and evict last. In one embodiment, data belonging to the evict first data class is raster operations data with little reuse potential. The frame buffer logic uses a notification sorter to organize dirty data notifications, where an entry in the notification sorter stores the DRAM bank page number, a first count of cache lines that have resident dirty data and a second count of cache lines that have resident evict_first dirty data associated with that DRAM bank. The frame buffer logic transmits dirty data associated with an entry when the first count reaches a threshold.

Techniques for evicting dirty data from a cache using a notification sorter and count thresholds

A system and method for buffering intermediate data in a processing pipeline architecture stores the intermediate data in a shared cache that is coupled between one or more pipeline processing units and an external memory. The shared cache provides storage that is used by multiple pipeline processing units. The storage capacity of the shared cache is dynamically allocated to the different pipeline processing units as needed, to avoid stalling the upstream units, thereby improving overall system throughput.

Padding buffer requests to avoid reads of invalid data

One embodiment of the invention sets forth a mechanism for evicting data from a data cache based on the data class of that data. The data stored in the cache lines in the data cache is categorized based on data classes that reflect the reuse potential of that data. The data classes are stored in a tag store, where each tag within the tag store corresponds to a single cache line within the data cache. When reserving a cache line for the data associated with a command, a tag look-up unit examines the data classes in the tag store to determine which data to evict. Data that has a low reuse potential is evicted at a higher priority than data that has a high reuse potential. Advantageously, evicting data that belongs to a data class that has a lower reuse potential reduces the number of cache misses within the system.

Multi-class data cache policies

One embodiment of the present invention sets forth a compression status cache configured to store compression information for blocks of memory stored within an external memory. A data cache unit is configured to request, in response to a cache miss, compressed data from the external memory based on compression information stored in the compression status bit cache. The compression status for active buffers is dynamically swapped into the compression status cache as needed. Different compression formats may be specified for one or more tiles within an active buffer. One advantage of the disclosed compression status cache is that a lame amount of attached memory may be allocated as compressible memory blocks, without incurring a corresponding die area cost because a portion of the compression status stored off chip in attached memory is cached in the compression status cache.

Compression status caching

A compression status bit cache provides on-chip availability of compression status bits used to determine how many bits are needed to access a potentially compressed block of memory. A backing store residing in a reserved region of attached memory provides storage for a complete set of compression status bits used to represent compression status of an arbitrarily large number of blocks residing in attached memory. Physical address remapping ('swizzling') used to distribute memory access patterns over a plurality of physical memory devices is partially replicated by the compression status bit cache to efficiently integrate allocation and access of the backing store data with other user data.

One embodiment of the present invention sets forth a technique for performing a memory access request to compressed data within a virtually mapped memory system comprising an arbitrary number of partitions. A virtual address is mapped to a linear physical address, specified by a page table entry (PTE). The PTE is configured to store compression attributes, which are used to locate compression status for a corresponding physical memory page within a compression status bit cache. The compression status bit cache operates in conjunction with a compression status bit backing store. If compression status is available from the compression status bit cache, then the memory access request proceeds using the compression status. If the compression status bit cache misses, then the miss triggers a fill operation from the backing store. After the fill completes, memory access proceeds using the newly filled compression status information.

Efficient line and page organization for compression status bit caching

One embodiment of the present invention sets forth a compression status bit cache with deterministic latency for isochronous memory clients of compressed memory. The compression status bit cache improves overall memory system performance by providing on-chip availability of compression status bits that are used to size and interpret a memory access request to compressed memory. To avoid non-deterministic latency when an isochronous memory client accesses the compression status bit cache, two design features are employed. The first design feature involves bypassing any intermediate cache when the compression status bit cache reads a new cache line in response to a cache read miss, thereby eliminating additional, potentially non-deterministic latencies outside the scope of the compression status bit cache. The second design feature involves maintaining a minimum pool of clean cache lines by opportunistically writing back dirty cache lines and, optionally, temporarily blocking non-critical requests that would dirty already clean cache lines. With clean cache lines available to be overwritten quickly, the compression status bit cache avoids incurring additional miss write back latencies.

Compression status bit cache with deterministic isochronous latency

Storing dynamically sized buffers within a cache

Systems and methods are disclosed for managing the number of affirmatively associated cache lines related to the different sets of a data cache unit. A tag look-up unit implements two thresholds, which may be configurable thresholds, to manage the number of cache lines related to a given set that store dirty data or are reserved for in-flight read requests. If the number of affirmatively associated cache lines in a given set is equal to a maximum threshold, the tag look-up unit stalls future requests that require an available cache line within that set to be affirmatively associated. To reduce the number of stalled requests, the tag look-up unit transmits a high priority clean notification to a frame buffer logic when the number of affirmatively associated cache lines in a given set approaches the maximum threshold. The frame buffer logic then processes requests associated with that set preemptively.

Cache and associated method with frame buffer managed dirty data pull and high-priority clean mechanism

One embodiment of the invention sets forth a mechanism for efficiently write dirty data from the L2 cache to a DRAM. A dirty data notification, including a memory address of the dirty data, is transmitted by the L2 cache to a frame buffer logic when dirty data is stored in the L2 cache. The frame buffer logic uses a page-stream sorter to organize dirty data notifications based on the bank page associated with the memory addresses included in the dirty data notifications. The page-stream sorter includes multiple sets with entries that may be associated with different bank pages in the DRAM. The frame buffer logic transmits dirty data associated with an entry that has a maximum threshold of dirty data notifications to the DRAM. The frame buffer logic also transmits dirty data associated with the oldest entry when the number of entries in a set reaches a maximum threshold.

System and method for cleaning dirty data in a cache via frame buffer logic

A system and method for converting data from one format to another in a processing pipeline architecture. Data is stored in a shared cache that is coupled between one or more clients and an external memory. The shared cache provides storage that is used by multiple clients rather than being dedicated to separately convert the data format for each client. Each client may interface with the memory using a different format, such as a compressed data format. Data is converted to the format expected by the particular client as it is read from the cache and output to the client during a read operation. Bytes of a cache line may be remapped to bytes of an unpack register for output to a na&#xef;ve client, which may be configured to perform texture mapping operations. Data is converted from the client format to the memory format as it is stored into the cache during a write operation.

Growing community of inventors

Austin, TX, United States of America

James P Roberts