Abstract: An apparatus and method are provided for maintaining a counter value. The apparatus has first counter control circuitry for maintaining a first counter value representing a first portion of a hybrid counter value, and second counter control circuitry for maintaining a second counter value representing a second portion of the hybrid counter value, wherein the second portion is a higher order portion of the hybrid counter value than the first portion. The first counter control circuitry is arranged to maintain the first counter value as a binary value that indicates a magnitude of the first counter value, the first counter control circuitry comprising adder circuitry that is responsive to an adjustment value to update the first counter value by performing an addition operation to add the adjustment value to a current binary value of the first counter value, and to generate a carry out signal which is set when a carry out is generated by the addition operation.

Abstract: Coherency control circuitry (10) supports processing of a safe-speculative-read transaction received from a requesting master device (4). The safe-speculative-read transaction is of a type requesting that target data is returned to a requesting cache (11) of the requesting master device (4) while prohibiting any change in coherency state associated with the target data in other caches (12) in response to the safe-speculative-read transaction. In response, at least when the target data is cached in a second cache associated with a second master device, at least one of the coherency control circuitry (10) and the second cache (12) is configured to return a safe-speculative-read response while maintaining the target data in the same coherency state within the second cache. This helps to mitigate against speculative side-channel attacks.

Abstract: Apparatuses and method are disclosed for protecting the integrity of data stored in a protected area of memory. Data in the protected area of memory is retrieved in data blocks and an authentication code is associated with a memory granule contiguously comprising a first data block and a second data block. Calculation of the authentication code comprises a cryptographic calculation based on a first hash value determined from the first data block and a second hash value determined from the second data block. A hash value cache is provided to store hash values determined from data blocks retrieved from the protected area of the memory. When the first data block and its associated authentication code are retrieved from memory, a lookup for the second hash value in the hash value cache is performed, and a verification authentication code is calculated for the memory granule to which that data block belongs.

Abstract: An apparatus comprises memory storage circuitry comprising a plurality of memory storage locations to store data; an interface to receive an address from a requester; decryption circuitry to obtain a decrypted address by decrypting, based on a decryption key, an address received from the requester; and access control circuitry to select, based on the decrypted address obtained by the decryption circuitry, a memory storage location of the memory storage circuitry to be accessed.

Abstract: There is herein provided a compound of formula I or a pharmaceutically acceptable salt thereof, for use in the treatment of cancer and/or the treatment or prevention of a viral infection, wherein A1, A2, L1, R1, R2 and n have meanings as provided in the description.

Abstract: An apparatus comprises memory storage circuitry comprising a plurality of memory storage locations to store data; an interface to receive an address from a requester; decryption circuitry to obtain a decrypted address by decrypting, based on a decryption key, an address received from the requester; and access control circuitry to select, based on the decrypted address obtained by the decryption circuitry, a memory storage location of the memory storage circuitry to be accessed.

Abstract: An apparatus and method are provided for maintaining a counter value. The apparatus has first counter control circuitry for maintaining a first counter value representing a first portion of a hybrid counter value, and second counter control circuitry for maintaining a second counter value representing a second portion of the hybrid counter value, wherein the second portion is a higher order portion of the hybrid counter value than the first portion. The first counter control circuitry is arranged to maintain the first counter value as a binary value that indicates a magnitude of the first counter value, the first counter control circuitry comprising adder circuitry that is responsive to an adjustment value to update the first counter value by performing an addition operation to add the adjustment value to a current binary value of the first counter value, and to generate a carry out signal which is set when a carry out is generated by the addition operation.

Abstract: A system, apparatus and method for secure functions and manipulating cache line data. The method includes generating cache block addresses from a subset of bits, i.e. tag bits, of a cache address and hashing the cache block addresses with one or more secure functions that use keys to generate secure indexes.

Abstract: A cache apparatus is provided comprising a data storage structure providing N cache ways that each store data as a plurality of cache blocks. The data storage structure is organised as a plurality of sets, where each set comprises a cache block from each way, and further the data storage structure comprises a first data array and a second data array, where at least the second data array is set associative. A set associative tag storage structure stores a tag value for each cache block, with that set associative tag storage structure being shared by the first and second data arrays. Control circuitry applies an access likelihood policy to determine, for each set, a subset of the cache blocks of that set to be stored within the first data array.

Abstract: Address translation circuitry performs virtual-to-physical address translations using a page table hierarchy of page table entries, wherein a translation between a virtual address and a physical address is defined in a last level page table entry of the page table hierarchy. The address translation circuitry is responsive to receipt of the virtual address to perform a translation determination with reference to the page table hierarchy, wherein an intermediate level page table entry of the page table hierarchy stores an intermediate level pointer to the last level page table entry.

Abstract: A system, apparatus and method for secure functions and manipulating cache line data. The method includes generating cache block addresses from a subset of bits, i.e. tag bits, of a cache address and hashing the cache block addresses with one or more secure functions that use keys to generate secure indexes.

Abstract: A compound of formula (I) or a pharmaceutically acceptable salt thereof. The compound is useful in therapy, e.g. for the treatment of cancers, inflammation, autoimmune diseases and graft-versus host diseases (e.g. in transplantation patients). A pharmaceutical composition comprising the compound or its salt and a method for preparing the compound.

Abstract: An apparatus and method are described, the apparatus comprising memory control circuitry configured to control access to data stored in memory, and memory security circuitry configured to generate encrypted data to be stored in the memory, the encrypted data being based on target data and a first one-time-pad (OTP). In response to an OTP update event indicating that the first OTP is to be updated to a second OTP different to the first OTP, the memory security circuitry is configured to generate a re-encryption value based on the first OTP and the second OTP, and the memory security circuitry is configured to issue a re-encryption request to cause updated encrypted data to be generated in a downstream component based on the encrypted data and the re-encryption value and to cause the encrypted data to be replaced in the memory by the updated encrypted data.

Abstract: There is provided an apparatus that includes an input port to receive, from a requester, any one of: a lookup operation comprising an input address, and a maintenance operation. Maintenance queue circuitry stores a maintenance queue of at least one maintenance operation and address storage stores a translation between the input address and an output address in an output address space. In response to receiving the input address, the output address is provided in dependence on the maintenance queue. In response to storing the maintenance operation, the maintenance queue circuitry causes an acknowledgement to be sent to the requester. By providing a separate maintenance queue for performing the maintenance operation, there is no need for a requester to be blocked while maintenance is performed.

Abstract: Coherency control circuitry (10) supports processing of a safe-speculative-read transaction received from a requesting master device (4). The safe-speculative-read transaction is of a type requesting that target data is returned to a requesting cache (11) of the requesting master device (4) while prohibiting any change in coherency state associated with the target data in other caches (12) in response to the safe-speculative-read transaction. In response, at least when the target data is cached in a second cache associated with a second master device, at least one of the coherency control circuitry (10) and the second cache (12) is configured to return a safe-speculative-read response while maintaining the target data in the same coherency state within the second cache. This helps to mitigate against speculative side-channel attacks.

Abstract: Broadly speaking, embodiments of the present technique provide an apparatus and methods for improved wear-levelling in non-volatile memory (NVM) devices. In particular, the present wear-levelling techniques operate on small blocks within a memory device, at a finer scale/granularity than that used by common wear-levelling techniques which often remap large blocks (e.g. several kilobytes) of data.

Abstract: There is herein provided a compound of formula I (I) or a pharmaceutically acceptable salt thereof, for use in the treatment of cancer and/or the treatment or prevention of a viral infection, wherein A1, A2, L1, R1, R2 and n have meanings as provided in the description.

Abstract: There is provided an apparatus that includes an input address port to receive an input address from processor circuitry. Address storage stores a translation between the input address and an output address in an output address space. An output address port outputs the output address. An input data port receives data. Data storage stores the data. An output data port outputs the data stored in the data storage and control circuitry causes the data storage to store the translation between the input address and the output address. The control circuitry issues a signal to cause a page walk to occur in response to the input address being absent from the address storage and the data storage.

Abstract: An apparatus comprises control circuitry to control access to a memory implemented using a memory technology providing variable access latency. The control circuitry has request handling circuitry to identify an execution context switch comprising a transition from servicing memory access requests associated with a first execution context to servicing memory access requests associated with a second execution context. At least when the execution context switch meets a predetermined condition, a delay masking action is triggered to control subsequent memory access requests associated with the second execution context, for which the required data is already stored in the memory, to be serviced with a response delay which is independent of which addresses were accessed by the memory access requests associated with the first execution context. This can help guard against attacks which aim to exploit variation in response latency to gain insight into the addresses accessed by a victim execution context.

Abstract: Memory address translation apparatus comprises page table access circuitry to access a page table to retrieve translation data; a translation data buffer to store one or more instances of the translation data, comprising: an array of storage locations arranged in rows and columns; a row buffer comprising a plurality of entries and comparison circuitry responsive to a key value dependent upon at least the initial memory address, to compare the key value with information stored in each of at least one key entry and an associated value entry for storing at least a representation of a corresponding output memory address, and to identify which of the at least one key entry, if any, is a matching key entry storing information matching the key value; and output circuitry to output, when there is a matching key entry, at least the representation of the output memory address.