Apple Inc.

Danny Gal

Liran Fishel

Nir Nissan

Assaf Metuki

Etai Zaltsman

Lukas Polok

Embodiments of the present disclosure relate to debugging of an accelerator circuit using a packet limit breakpoint. A vector circuit reads a subset of instruction packets from an instruction memory and receives a portion of input data from a data memory corresponding to the subset of instruction packets. The vector circuit executes a set of vector operations in accordance with multiple instruction packets from the subset using data from the received portion of input data identified in the multiple instruction packets to generate output data. A program counter control circuit coupled to the instruction memory triggers a breakpoint in a program stored in the instruction memory causing the accelerator circuit to stop executing remaining instruction packets in the program following the multiple instruction packets responsive to a number of instruction packets executed in the program from a time instant of an event reaching a predetermined number.

Debugging of accelerator circuit for mathematical operations using packet limit breakpoint

Embodiments of the present disclosure relate to sequentially loading keypoint descriptors of a previous image and comparing them with a plurality of keypoint descriptors of a current image. The keypoint descriptors of the previous image are stored and accessed from a system memory while the keypoint descriptors of the current image are stored and accessed from a local memory. Hence, the keypoint descriptors of the previous image are received only once at a descriptor match circuit while the keypoint descriptors of the current image are received multiple times for comparison against different keypoint descriptors of the previous image.

Single read of keypoint descriptors of image from system memory for efficient header matching

Embodiments of the present disclosure relate to selecting a subset of keypoint descriptors of two images for match operation based on their orientation angles indicated in headers of the keypoint descriptors. The keypoint descriptors in the two images are matched by first comparing their headers and then performing vector distance determination. During the header comparison operation, a header of a descriptor of a first image is compared only with headers of keypoint descriptors of a second image in a discrete orientation angle range corresponding to an orientation angle indicated by the header of the first image descriptor or keypoint descriptors of the second image in adjacent discrete orientation angle ranges. After the headers of the keypoint descriptors satisfying one or more matching criteria are determined, distance determination operations are performed between the keypoint descriptors while the remaining keypoint descriptors are discarded without determining their distances.

Filtering of keypoint descriptors based on orientation angle

Embodiments of the present disclosure relate to an accelerator circuit with a dynamic immediate values table (IVT). The accelerator circuit includes an instruction memory, a data memory, and a vector circuit with the IVT storing multiple immediate values at multiple entries. The vector circuit reads a subset of instructions from the instruction memory, each instruction including at least one corresponding pointer to at least one corresponding entry in the IVT. The vector circuit further receives a subset of input data from the data memory corresponding to the subset of instructions. The vector circuit performs a respective operation in accordance with each instruction from the subset of instructions using a corresponding data vector of the received subset of input data identified in each instruction and at least one corresponding immediate value from the IVT pointed by the at least one corresponding pointer to generate corresponding output data.

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Hod-Hasharon, Israel

Danny Gal