Described is a data cache implementing hybrid writebacks and writethroughs. A processing system includes a memory, a memory controller, and a processor. The processor includes a data cache including cache lines, a write buffer, and a store queue. The store queue writes data to a hit cache line and an allocated entry in the write buffer when the hit cache line is initially in at least a shared coherence state, resulting in the hit cache line being in a shared coherence state with data and the allocated entry being in a modified coherence state with data. The write buffer requests and the memory controller upgrades the hit cache line to a modified coherence state with data based on tracked coherence states. The write buffer retires the data upon upgrade. The data cache writebacks the data to memory for a defined event.

Described is a data cache implementing hybrid writebacks and writethroughs. A processing system includes a memory, a memory controller, and a processor. The processor includes a data cache including cache lines, a write buffer, and a store queue. The store queue writes data to a hit cache line and an allocated entry in the write buffer when the hit cache line is initially in at least a shared coherence state, resulting in the hit cache line being in a shared coherence state with data and the allocated entry being in a modified coherence state with data. The write buffer requests and the memory controller upgrades the hit cache line to a modified coherence state with data based on tracked coherence states. The write buffer retires the data upon upgrade. The data cache writebacks the data to memory for a defined event.

Techniques are disclosed relating to compression of data stored at different cache levels. In some embodiments, a memory system implements a storage hierarchy that includes first cache circuitry and second cache circuitry at different levels of the hierarchy. Processor circuitry generates write data to be written to the memory system. In some embodiments, first compression circuitry is configured to compress a first block of write data in response to full accumulation of the first block in the first cache circuitry and second compression circuitry is configured to compress a second block of write data in response to full accumulation of the second block in the second cache circuitry. Write circuitry may write the first and second compressed blocks of data in a single combined write to a higher level in the storage hierarchy.

Method and apparatus for managing a front-end cache formed of ferroelectric memory element (FME) cells. Prior to storage of writeback data associated with a pending write command from a client device, an intelligent cache manager circuit forwards a first status value indicative that sufficient capacity is available in the front-end cache for the writeback data. Non-requested speculative readback data previously transferred to the front-end cache from the main NVM memory store may be jettisoned to accommodate the writeback data. A second status value may be supplied to the client device if insufficient capacity is available to store the writeback data in the front-end cache, and a different, non-FME based cache may be used in such case. Mode select inputs can be supplied by the client device specify a particular quality of service level for the front-end cache, enabling selection of suitable writeback and speculative readback data processing strategies.

A system and a method to allocate data to a first cache increments a first counter if a reuse indicator for the data indicates that the data is likely to be reused and decremented the counter if the reuse indicator for the data indicates that the data is likely not to be reused. A second counter is incremented upon eviction of the data from the second cache, which is a higher level cache than the first cache. The data is allocated to the first cache if the value of the first counter is equal to or greater than the first predetermined threshold or the value of the second counter equals zero, and the data is bypassed from the first cache if the value of the first counter is less than the first predetermined threshold and the value of the second counter is not equal to zero.

A system and a method to allocate data to a first cache increments a first counter if a reuse indicator for the data indicates that the data is likely to be reused and decremented the counter if the reuse indicator for the data indicates that the data is likely not to be reused. A second counter is incremented upon eviction of the data from the second cache, which is a higher level cache than the first cache. The data is allocated to the first cache if the value of the first counter is equal to or greater than the first predetermined threshold or the value of the second counter equals zero, and the data is bypassed from the first cache if the value of the first counter is less than the first predetermined threshold and the value of the second counter is not equal to zero.

Provided are a computer program product, integrated cache manager, and method for maintaining data in a first level memory and buckets representing regions of memory devices to extend data cache. A plurality of buckets represent distinct regions of memory devices. The buckets are associated with different threshold access count ranges. Data having an access count is stored in one of the buckets associated with a threshold access count range including the access count of the data to store. Data evicted from a first level memory is copied to an initial bucket comprising one of the buckets. Data is moved from a source bucket comprising one of the buckets, including the initial bucket, to a target bucket of the buckets having a target threshold access count range including an access count of the data to move.

Methods, systems, and devices for cache architectures for memory devices are described. For example, a memory device may include a main array having a first set of memory cells, a cache having a second set of memory cells, and a cache delay register configured to store an indication of cache addresses associated with recently performed access operations. In some examples, the cache delay register may be operated as a first-in-first-out (FIFO) register of cache addresses, where a cache address associated with a performed access operation may be added to the beginning of the FIFO register, and a cache address at the end of the FIFO register may be purged. Information associated with access operations on the main array may be maintained in the cache, and accessed directly (e.g., without another accessing of the main array), at least as long as the cache address is present in the cache delay register.

Broadly speaking, embodiments of the present technique provide apparatus and methods for improved wear-levelling in (volatile and non-volatile) memories. In particular, the present wear-levelling techniques comprise moving static memory states within a memory, in order to substantially balance writes across all locations within the memory.

A cache unit that is configured to retain: a plurality of cache blocks; a plurality of owner indicators, and a plurality of validity marks. For each cache block of the plurality of cache blocks exists a corresponding owner indicator in the plurality of owner indicators. An owner indicator corresponding to a cache block is capable of identifying an entity that caused the cache block to be fetched to the cache unit. For each cache block of the plurality of cache blocks exists a corresponding validity mark in the plurality of validity marks. A validity mark corresponding to the cache block indicates whether a validation process performed on the cache block upon fetching thereof was successful. The cache unit may be useful for secure execution.