Abstract: A method includes determining, by a level one (L1) controller, to change a size of a L1 main cache; servicing, by the L1 controller, pending read requests and pending write requests from a central processing unit (CPU) core; stalling, by the L1 controller, new read requests and new write requests from the CPU core; writing back and invalidating, by the L1 controller, the L1 main cache. The method also includes receiving, by a level two (L2) controller, an indication that the L1 main cache has been invalidated and, in response, flushing a pipeline of the L2 controller; in response to the pipeline being flushed, stalling, by the L2 controller, requests received from any master; reinitializing, by the L2 controller, a shadow L1 main cache. Reinitializing includes clearing previous contents of the shadow L1 main cache and changing the size of the shadow L1 main cache.

Abstract: A digital data processor includes an instruction memory storing instructions specifying a data processing operation and a data operand field, an instruction decoder coupled to the instruction memory for recalling instructions from the instruction memory and determining the operation and the data operand, and an operational unit coupled to a data register file and to an instruction decoder to perform a data processing operation upon an operand corresponding to an instruction decoded by the instruction decoder and storing results of the data processing operation. The operational unit is configured to perform a table write in response to a look up table initialization instruction by duplicating at least one data element from a source data register to create duplicated data elements, and writing the duplicated data elements to a specified location in a specified number of at least one table and a corresponding location in at least one other table.

Abstract: A digital data processor includes a multi-stage butterfly network, which is configured to, in response to a look up table read instruction, receive look up table data from an intermediate register, reorder the look up table data based on control signals comprising look up table configuration register data, and write the reordered look up table data to a destination register specified by the look up table read instruction.

Abstract: A caching system including a first sub-cache, a second sub-cache, coupled in parallel with the first sub-cache, for storing write-memory commands that are not cached in the first sub-cache, the second sub-cache including privilege bits configured to store an indication that a corresponding cache line of the second sub-cache is associated with a level of privilege, and wherein the second sub-cache is further configured to receive a first write memory command for a memory address associated with a first level of privilege, store, in the second sub-cache, first data associated with the first write memory command and the level of privilege associated with the cache line, receive a second write memory command for the cache line, the second write memory command associated with a second level of privilege, merge the first level of privilege with the second level of privilege, and output the merged privilege level with the cache line.

Abstract: A caching system including a first sub-cache and a second sub-cache in parallel with the first sub-cache, wherein the second sub-cache includes a set of cache lines, line type bits configured to store an indication that a corresponding cache line of the set of cache lines is configured to store write-miss data, and an eviction controller configured to flush stored write-miss data based on the line type bits.

Abstract: A system includes a non-coherent component; a coherent, non-caching component; a coherent, caching component; and a level two (L2) cache subsystem coupled to the non-coherent component, the coherent, non-caching component, and the coherent, caching component. The L2 cache subsystem includes a L2 cache; a shadow level one (L1) main cache; a shadow L1 victim cache; and a L2 controller. The L2 controller is configured to receive and process a first transaction from the non-coherent component; receive and process a second transaction from the coherent, non-caching component; and receive and process a third transaction from the coherent, caching component.

Abstract: Methods, apparatus, systems and articles of manufacture to facilitate write miss caching in cache system are disclosed. An example apparatus includes a first cache storage; a second cache storage, wherein the second cache storage includes a first portion operable to store a first set of data evicted from the first cache storage and a second portion; a cache controller coupled to the first cache storage and the second cache storage and operable to: receive a write operation; determine that the write operation produces a miss in the first cache storage; and in response to the miss in the first cache storage, provide write miss information associated with the write operation to the second cache storage for storing in the second portion.

Abstract: An apparatus includes a CPU core and a L1 cache subsystem including a L1 main cache, a L1 victim cache, and a L1 controller. The apparatus includes a L2 cache subsystem including a L2 main cache, a shadow L1 main cache, a shadow L1 victim cache, and a L2 controller configured to receive a read request from the L1 controller as a single transaction. Read request includes a read address, a first indication of an address and a coherence state of a cache line A to be moved from the L1 main cache to the L1 victim cache to allocate space for data returned in response to the read request, and a second indication of an address and a coherence state of a cache line B to be removed from the L1 victim cache in response to the cache line A being moved to the L1 victim cache.

Abstract: In described examples, a coherent memory system includes a central processing unit (CPU), and first and second level caches, each with a cache controller. The CPU is arranged to execute program instructions to manipulate data in at least a first or second secure context. Each of the first and second caches stores a secure code for indicating the secure context by which data for a respective cache line is received. The first and second level caches maintain coherency in response to comparing the secure codes of respective lines of cache and executing a cache coherency operation in response. A requestor coupled to the second level cache may send a coherence read transaction to the second level cache controller, which upon an affirmative security check, generates a snoop read transaction and sends the same to the first level cache.

Abstract: Techniques related to executing a plurality of instructions by a processor comprising receiving a first instruction configured to cause the processor to output a first data value to a first address in a first data cache, outputting, by the processor, the first data value to a second address in a second data cache, receiving a second instruction configured to cause a streaming engine associated with the processor to prefetch data from the first data cache, determining that the first data value has not been outputted from the second data cache to the first data cache, stalling execution of the second instruction, receiving an indication, from the second data cache, that the first data value has been output from the second data cache to the first data cache, and resuming execution of the second instruction based on the received indication.

Abstract: Methods, apparatus, systems and articles of manufacture to facilitate atomic compare and swap in cache for a coherent level 1 data cache system are disclosed. An example system includes a cache storage; a cache controller coupled to the cache storage wherein the cache controller is operable to: receive a memory operation that specifies a key, a memory address, and a first set of data; retrieve a second set of data corresponding to the memory address; compare the second set of data to the key; based on the second set of data corresponding to the key, cause the first set of data to be stored at the memory address; and based on the second set of data not corresponding to the key, complete the memory operation without causing the first set of data to be stored at the memory address.

Abstract: A digital data processor includes an instruction memory storing instructions each specifying a data processing operation and at least one data operand field, an instruction decoder coupled to the instruction memory for sequentially recalling instructions from the instruction memory and determining the data processing operation and the at least one data operand, and at least one operational unit coupled to a data register file and to an instruction decoder to perform a data processing operation upon at least one operand corresponding to an instruction decoded by the instruction decoder and storing results of the data processing operation. The operational unit is configured to increment histogram values in response to a histogram instruction by incrementing a bin entry at a specified location in a specified number of at least one histogram.

Abstract: Techniques for caching data are provided that include receiving, by a caching system, a write memory command for a memory address, the write memory command associated with a first color tag, determining, by a first sub-cache of the caching system, that the memory address is not cached in the first sub-cache, determining, by second sub-cache of the caching system, that the memory address is not cached in the second sub-cache, storing first data associated with the first write memory command in a cache line of the second sub-cache, storing the first color tag in the second sub-cache, receiving a second write memory command for the cache line, the write memory command associated with a second color tag, merging the second color tag with the first color tag, storing the merged color tag, and evicting the cache line based on the merged color tag.

Abstract: Methods, apparatus, systems and articles of manufacture are disclosed to facilitate read-modify-write support in a victim cache. An example apparatus includes a first storage coupled to a controller, a second storage coupled to the controller and parallel coupled to the first storage, and a storage queue coupled to the first storage, the second storage, and to the controller, the storage queue to obtain a memory operation from the controller indicating an address and a first set of data, obtain a second set of data associated with the address from at least one of the first storage and the second storage, merge the first set of data and the second set of data to produce a third set of data, and provide the third set of data for writing to at least one of the first storage and the second storage.

Abstract: Methods, apparatus, systems and articles of manufacture are disclosed to facilitate fully pipelined read-modify-write support in level 1 data cache using store queue and data forwarding. An example apparatus includes a first storage, a second storage, a store queue coupled to the first storage and the second storage, the store queue operable to receive a first memory operation specifying a first set of data, process the first memory operation for storing the first set of data in at least one of the first storage and the second storage, receive a second memory operation, and prior to storing the first set of data in the at least one of the first storage and the second storage, feedback the first set of data for use in the second memory operation.

Abstract: A method includes receiving, by a L2 controller, a request to perform a global operation on a L2 cache and preventing new blocking transactions from entering a pipeline coupled to the L2 cache while permitting new non-blocking transactions to enter the pipeline. Blocking transactions include read transactions and non-victim write transactions. Non-blocking transactions include response transactions, snoop transactions, and victim transactions.

Abstract: In described examples, a coherent memory system includes a central processing unit (CPU) and first and second level caches. The CPU is arranged to execute program instructions to manipulate data in at least a first or second secure context. Each of the first and second caches stores a secure code for indicating the at least first or second secure contexts by which data for a respective cache line is received. The first and second level caches maintain coherency in response to comparing the secure codes of respective lines of cache and executing a cache coherency operation in response.

Abstract: An apparatus including a CPU core and a L1 cache subsystem coupled to the CPU core. The L1 cache subsystem includes a L1 main cache, a L1 victim cache, and a L1 controller. The apparatus includes a L2 cache subsystem coupled to the L1 cache subsystem. The L2 cache subsystem includes a L2 main cache, a shadow L1 main cache, a shadow L1 victim cache, and a L2 controller. The L2 controller receives an indication from the L1 controller that a cache line A is being relocated from the L1 main cache to the L1 victim cache; in response to the indication, update the shadow L1 main cache to reflect that the cache line A is no longer located in the L1 main cache; and in response to the indication, update the shadow L1 victim cache to reflect that the cache line A is located in the L1 victim cache.

Abstract: Methods, apparatus, systems and articles of manufacture to reduce bank pressure using aggressive write merging are disclosed. An example apparatus includes a first cache storage; a second cache storage; a store queue coupled to at least one of the first cache storage and the second cache storage and operable to: receive a first memory operation; process the first memory operation for storing the first set of data in at least one of the first cache storage and the second cache storage; receive a second memory operation; and prior to storing the first set of data in the at least one of the first cache storage and the second cache storage, merge the first memory operation and the second memory operation.

Abstract: Methods, apparatus, systems and articles of manufacture are disclosed facilitate read-modify-write support in a coherent victim cache with parallel data paths. An example apparatus includes a random-access memory configured to be coupled to a central processing unit via a first interface and a second interface, the random-access memory configured to obtain a read request indicating a first address to read via a snoop interface, an address encoder coupled to the random-access memory, the address encoder to, when the random-access memory indicates a hit of the read request, generate a second address corresponding to a victim cache based on the first address, and a multiplexer coupled to the victim cache to transmit a response including data obtained from the second address of the victim cache.