Texas Instruments Corporation

Naveen Bhoria

Timothy David Anderson

Pete Michael Hippleheuser

Abhijeet Ashok Chachad

David Matthew Thompson

Duc Quang Bui

Raguram Damodaran

Dheera Balasubramanian Samudrala

Neelima Muralidharan

Kai Chirca

Ramakrishnan Venkatasubramanian

Rama Venkatasubramanian

Joseph R Zbiciak

Alan Davis

Matthew D Pierson

Daniel Brad Wu

Aman A Kokrady

Dheera Balasubramanian

Peter Michael Hippleheuser

Pramod Kumar Swami

Joseph Raymond Michael Zbiciak

Son Hung Tran

Sahithi Krishna

Jonathan (Son) Hung Tran

Ramakrishnan Vankatasubramanian

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.

Write merging on stores with different tags

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.

Methods and apparatus to facilitate write miss caching in cache system

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.

Methods and apparatus to facilitate read-modify-write support in a coherent victim cache with parallel data paths

An example system includes first and second level memories and first and second memory controllers respectively coupled thereto. The system also includes a shadow cache associated with the second level memory and coupled to the second memory controller, which is also coupled to the first memory controller. In response to a generated read operation that includes a secure code, the second memory controller determines whether an address of the read operation matches an address that is tagged in the shadow cache; and determine whether the secure code of the read operation matches a secure code of a cache line hit by the read operation. The second memory controller then performs one of two sets of additional operations, depending on whether or not the address of the read operation matches the address tagged in the shadow cache and whether or not the secure code of the read operation matches the secure code of the cache line.

Multi-level cache security

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.

Hardware coherence for memory controller

Disclosed embodiments relate to look up table operations implemented in a digital data processor. A look up table read instruction recalls data elements of a specified data size from table(s) and stores recalled data elements in successive slots in a destination register. Disclosed embodiments promote data elements to a larger size with selected sign or zero extension. A source operand register stores vector offsets from a table start address. A destination operand stores the results of the look up table read. The look up table instruction implies a base address register and a configuration register. The base address register stores a table base address. The configuration register sets various look up table read operation parameters.

Look up table with data element promotion

Methods, apparatus, systems and articles of manufacture to facilitate atomic operation in victim cache are disclosed. An example system includes a first cache storage to store a first set of data; a second cache storage to store a second set of data that has been evicted from the first cache storage; and a storage queue coupled to the first cache storage and the second cache storage, the storage queue including: an arithmetic component to: receive the second set of data from the second cache storage in response to a memory operation; and perform an arithmetic operation on the second set of data to produce a third set of data; and an arbitration manager to store the third set of data in the second cache storage.

Methods and apparatus to facilitate atomic operations in victim cache

A caching system including a first sub-cache, a second sub-cache, coupled in parallel with the first sub-cache, for storing cache data evicted from the first sub-cache and write-memory commands that are not cached in the first sub-cache, and a cache controller configured to receive two or more cache commands, determine a conflict exists between the received two or more cache commands, determine a conflict resolution between the received two or more cache commands, and sending the two or more cache commands to the first sub-cache and the second sub-cache.

Victim cache with write miss merging

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 the 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 at least one operational unit is configured to perform a table write in response to a look up table write instruction by writing at least one data element from a source data register to a specified location in a specified number of at least one table.

Look-up table write

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.

Write merging on stores with different privilege levels

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.

Cache size change

A caching system including a first sub-cache, and a second sub-cache, coupled in parallel with the first cache, for storing cache data evicted from the first sub-cache and write-memory commands that are not cached in the first sub-cache, and wherein the second sub-cache includes: color tag bits configured to store an indication that a corresponding cache line of the second sub-cache storing write miss data is associated with a color tag, and an eviction controller configured to evict cache lines of the second sub-cache storing write-miss data based on the color tag associated with the cache line.

Hybrid victim cache and write miss buffer with fence operation

Methods, apparatus, systems and articles of manufacture are disclosed for multi-banked victim cache with dual datapath. An example cache system includes a storage element that includes banks operable to store data, ports operable to receive memory operations in parallel, wherein each of the memory operations has a respective address, and a plurality of comparators coupled such that each of the comparators is coupled to a respective port of the ports and a respective bank of the banks and is operable to determine whether a respective address of a respective memory operation received by the respective port corresponds to the data stored in the respective bank.

Methods and apparatus for multi-banked victim cache with dual datapath

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.

Look-up table initialize

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.

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Plano, TX, United States of America

Naveen Bhoria