Abstract: A graphics processing system includes a tiling unit configured to tile a scene into a plurality of tiles. A processing unit identifies tiles of the plurality of tiles that are each associated with at least a predetermined number of primitives. A memory management unit allocates a portion of memory to each of the identified tiles and does not allocate a portion of memory for each of the plurality of tiles that are not identified by the processing unit. A rendering unit renders each of the identified tiles and does not render tiles that are not identified by the processing unit.

Abstract: Methods and systems for performing a convolution transpose operation between an input tensor having a plurality of input elements and a filter comprising a plurality of filter weights. The method includes: dividing the filter into a plurality of sub-filters; performing, using hardware logic, a convolution operation between the input tensor and each of the plurality of sub-filters to generate a plurality of sub-output tensors, each sub-output tensor comprising a plurality of output elements; and interleaving, using hardware logic, the output elements of the plurality of sub-output tensors to form a final output tensor for the convolution transpose.

Abstract: A graphics processing unit having multiple groups of processor cores for rendering graphics data for allocated tiles and outputting the processed data to regions of a memory resource. Scheduling logic allocates sets of tiles to the groups of processor cores to perform a first render, and at a time when at least one of the groups has not completed processing its allocated sets of one or more tiles as part of the first render, allocates at least one set of tiles for a second render to one of the other groups of processor cores for processing. Progress indication logic indicates progress of the first render, indicating regions of the memory resource for which processing for the first render has been completed. Progress check logic checks the progress indication in response to a request for access to a region of the memory resource as part of the second render and enables access that region of the resource in response to an indication that processing for the first render has been completed for that region.

Abstract: Systems and methods for processing primitive fragments in a rasterization phase of a graphics processing system wherein a rendering space is subdivided into a plurality of tiles. The method includes receiving a plurality of primitive fragments, each primitive fragment corresponding to a pixel sample in a tile; determining whether a depth buffer read is to be performed for hidden surface removal processing of one or more of the primitive fragments; sorting the primitive fragments into a priority queue and a non-priority queue based on the depth buffer read determinations; and performing hidden surface removal processing on the primitive fragments in the priority and non-priority queues wherein priority is given to the primitive fragments in the priority queue.

Abstract: In an aspect, an update unit can evaluate condition(s) in an update request and update one or more memory locations based on the condition evaluation. The update unit can operate atomically to determine whether to effect the update and to make the update. Updates can include one or more of incrementing and swapping values. An update request may specify one of a pre-determined set of update types. Some update types may be conditional and others unconditional. The update unit can be coupled to receive update requests from a plurality of computation units. The computation units may not have privileges to directly generate write requests to be effected on at least some of the locations in memory. The computation units can be fixed function circuitry operating on inputs received from programmable computation elements. The update unit may include a buffer to hold received update requests.

Abstract: A method of configuring a graphics processing unit includes generating configuration data that specifies a configuration to be adopted by the graphics processing unit. The configuration data is received at the graphics processing unit, which is configured in accordance with the configuration data by writing the configuration data into one or more registers of the graphics processing unit. It is determined whether the graphics processing unit is correctly configured in accordance with the configuration data by determining whether the configuration data has been correctly written into the one or more registers of the graphics processing unit. An error is determined to have occurred in response to determining that the graphics processing unit is not correctly configured in accordance with the configuration data.

Abstract: A method of rendering a scene formed by primitives in a graphics processing system. For a sequence of primitives, a pipeline fragment shading rate value and a primitive fragment shading rate value for a primitive are combined to produce a combined fragment shading rate value for the primitive. Fragment shading rate data representing the combined fragment shading rate value for the primitive is stored and data identifying the primitive is associated with the fragment shading rate data. For a subsequent primitive, it is determined whether or not a combined fragment shading rate value for the subsequent primitive is the same as for the preceding primitive. If it is the same, data identifying the subsequent primitive is associated with the fragment shading rate data that the data identifying the preceding primitive is associated with.

Abstract: A multicore hardware implementation of a deep neural network includes a plurality of layers arranged in plurality of layer groups. The input data to the network comprises a multidimensional tensor including one or more traversed dimensions that are traversed by strides in at least one layer of a first layer group, and one or more non-traversed dimensions. If a size of the input data in a first dimension is greater than a threshold, the hardware implementation splits the input data for the first layer group into at least a first tile and a second tile, along the first dimension. If the size of the input data in the first dimension is not greater than the threshold, the hardware implementation splits the evaluation of the first layer group into at least a first pass and a second pass, along a dimension other than the first dimension.

Abstract: A communications interface for interfacing between a host system and a state machine includes an event slot, the event slot comprising a plurality of registers including: a write register for writing by the host system, and a read register for reading by the host system, wherein the event slot is addressed from the host system by a single address location permitting the host system to write data to the write register and/or read data from the read register; and wherein the write register and the read register are individually addressable by the state machine.

Abstract: Methods of encoding and decoding are described which use a variable number of instruction words to encode instructions from an instruction set, such that different instructions within the instruction set may be encoded using different numbers of instruction words. To encode an instruction, the bits within the instruction are re-ordered and formed into instruction words based upon their variance as determined using empirical or simulation data. The bits in the instruction words are compared to corresponding predicted values and some or all of the instruction words that match the predicted values are omitted from the encoded instruction.

Abstract: Address generators for use in verifying an integrated circuit hardware design for an n-way set associative cache. The address generator is configured to generate, from a reverse hashing algorithm matching the hashing algorithm used by the n-way set associative cache, a list of cache set addresses that comprises one or more addresses of the main memory corresponding to each of one or more target sets of the n-way set associative cache. The address generator receives requests for addresses of main memory from a driver to be used to generate stimuli for testing an instantiation of the integrated circuit hardware design for the n-way set associative cache. In response to receiving a request the address generator provides an address from the list of cache set addresses.

Abstract: A system and method for performing intersection testing of rays in a ray tracing system. The ray tracing system uses a hierarchical acceleration structure comprising a plurality of nodes, each identifying one or more elements able to be intersected by a ray. The system makes use of a serial-mode ray intersection process, in which, when a ray intersects a bounding volume, a limited number of new ray requests are generated.

Abstract: Hardware implementations of, and methods for processing, a convolution layer of a DNN that comprise a plurality of convolution engines wherein the input data and weights are provided to the convolution engines in an order that allows input data and weights read from memory to be used in at least two filter-window calculations performed either by the same convolution engine in successive cycles or by different convolution engines in the same cycle. For example, in some hardware implementations of a convolution layer the convolution engines are configured to process the same weights but different input data each cycle, but the input data for each convolution engine remains the same for at least two cycles so that the convolution engines use the same input data in at least two consecutive cycles.

Abstract: A method of activating scheduling instructions within a parallel processing unit includes checking if an ALU targeted by a decoded instruction is full by checking a value of an ALU work fullness counter stored in the instruction controller and associated with the targeted ALU. If the targeted ALU is not full, the decoded instruction is sent to the targeted ALU for execution and the ALU work fullness counter associated with the targeted ALU is updated. If, however, the targeted ALU is full, a scheduler is triggered to de-activate the scheduled task by changing the scheduled task from the active state to a non-active state. When an ALU changes from being full to not being full, the scheduler is triggered to re-activate an oldest scheduled task waiting for the ALU by removing the oldest scheduled task from the non-active state.

Abstract: A wireless media distribution system is provided comprising an access point (6) for broadcasting media and a plurality of stations (2) for reception and playback of media. Each station is configured for receiving and decoding a timestamp in a beacon frame transmitted repeatedly from the access point. This is used to control the output signal of a station physical layer clock (12) which is then used as a clock source for an application layer time synchronisation protocol. This application layer time synchronisation protocol can then be used in the station to control an operating system clock (8) for regulating playback of media.

Abstract: Aspects relate to tracing rays in 3-D scenes that comprise objects that are defined by or with implicit geometry. In an example, a trapping element defines a portion of 3-D space in which implicit geometry exist. When a ray is found to intersect a trapping element, a trapping element procedure is executed. The trapping element procedure may comprise marching a ray through a 3-D volume and evaluating a function that defines the implicit geometry for each current 3-D position of the ray. An intersection detected with the implicit geometry may be found concurrently with intersections for the same ray with explicitly-defined geometry, and data describing these intersections may be stored with the ray and resolved.

Abstract: A method and encoding unit for encoding a block of pixels into a compressed data structure determines a set of Haar coefficients for a 2×2 quad of pixels of the block of pixels, which set includes a plurality of differential coefficients and an average coefficient. A first portion of the compressed data structure is determined using the differential coefficients and includes a first set of bits which indicates an order of the magnitudes of the differential coefficients, and a second set of bits which indicates a sign and an exponent for each of one or more of the differential coefficients which are non-zero. A second portion of the compressed data structure is determined using the average coefficient determined for the 2×2 quad of pixels. The compressed data structure is stored.

Abstract: Methods of memory allocation in which registers referenced by different groups of instances of the same task are mapped to individual logical memories. Other example methods describe the mapping of registers referenced by a task to different banks within a single logical memory and in various examples this mapping may take into consideration which bank is likely to be the dominant bank for the particular task and the allocation for one or more other tasks.

Abstract: Hardware logic arranged to normalise (or renormalise) an n-bit input number is described in which at least a proportion of a left shifting operation is performed in parallel with a leading zero count operation. In various embodiments the left shifting and the leading zero count are performed independently. In various other embodiments, a subset of the bits output by a leading zero counter are input to a left shifter and the output from the left shifter is input to a renormalisation block which completes the remainder of the left shifting operation independently of any further input from the leading zero counter.

Abstract: A method and apparatus are provided for tessellating patches of surfaces in a tile based three dimensional computer graphics rendering system. For each tile in an image a per tile list of primitive indices is derived for tessellated primitives which make up a patch. Hidden surface removal is then performed on the patch and any domain points which remain after hidden surface removal are derived. The primitives are then shaded for display.