An interrupt system for RISC-V architecture includes an original register in a CLIC, a pushmcause register, a pushmepc register, an interrupt response register, and an mtvt2 register; the pushmcause register is used to store a value in an mcause on a stack by means of an instruction; the pushmepc register is used to store a value in an mepc on a stack by means of an instruction; the interrupt response register is used to respond to a non-vectored interrupt request issued by a CLIC by means of an instruction, obtain an interrupt subroutine entry address, and modify a global interrupt enable; and the mtvt2 register is used to store a base address of an non-vectored interrupt in a CLIC mode.

Preemptive scheduling enclaves as disclosed herein support both cooperative and preemptive scheduling of in-enclave (IE) thread execution. These preemptive scheduling enclaves may include a scheduler configured to be executed as part of normal hardware interrupt processing by enclave threads. The scheduler identifies an IE thread to be scheduled and modifies enclave data structures so that when the enclave thread resumes processing after a hardware interrupt, the identified IE thread is executed, rather than the interrupted IE thread.

A method for testing an integrated circuit, comprising: accessing a database associated with a test template, wherein said test template is configured to test a selected function of the integrated circuit; storing, in said database, data corresponding to at least partial predicted results of one or more random instruction sequences generated based on said test template; generating, by an automated test generation tool, a random instruction sequence based on said test template; executing said instruction sequence by a hardware exerciser, in the integrated circuit; and comparing results of said instruction sequence with said at least partial predicted results, to verify a function of said integrated circuit.

Performing breakpoint detection via a cache includes detecting an occurrence of a memory access and identifying whether any cache line of the cache matches an address associated with the memory access. When a cache line does match the address associated with the memory access no breakpoint was encountered. When no cache line matches the address associated with the memory access embodiments identify whether any cache line matches the address associated with the memory access when one or more flag bits are ignored. When a cache line does match the address associated with the memory access when the one or more flag bits are ignored, embodiment perform a check for whether a breakpoint was encountered. Otherwise, embodiments process a cache miss.

A method includes for each processed interrupt: identifying an interrupt associated with a first interrupt number; determining that the interrupt is designated as a special interrupt, the special interrupt being an interrupt to be translated to a different interrupt number only if the hardware processor is in user mode; determining a current execution mode for the hardware processor; for each interrupt in operating system mode, delivering the interrupt as the first interrupt number; and for each interrupt in user mode: translating the first interrupt number to a second interrupt number; and delivering the interrupt as the second interrupt number, wherein the current execution mode is determined to be an operating system mode for at least one of the interrupts, and the current execution mode is determined to be a user mode for at least an additional one of the interrupts.

A processor includes processing engines, at least one performance counter, and a power control circuit. The at least one performance counter is to determine at least one interrupt rate metric for a first processing engine. The power control circuit is to determine, using the at least one performance counter, whether the at least one interrupt rate metric has reached a first threshold while the first processing engine is operating at a first frequency level, and in response to a determination that the at least one interrupt rate metric has reached the first threshold while the first processing engine is operating at the first frequency level, increase an operating frequency of the first processing engine from the first frequency level to a second frequency level.

Processing circuitry supports overlapped execution of vector instructions when at least one beat of a first vector instruction is performed in parallel with at least one beat of a second vector instruction. The processing circuitry also supports mixed-scalar-vector instructions for which one of a destination register and one or more source registers is a vector register and another is a scalar register. In a sequence including first and subsequent mixed-scalar-vector instructions, instances of relaxed execution which can potentially lead to uncertain and incorrect results are permitted by the processing circuitry when the instructions are separated by fewer than a predetermined number of intervening instructions. In practice the situations which lead to the uncertain results are very rare and so it is not justified providing relatively expensive dependency checking circuitry for eliminating such cases.

A interrupt control system and method based on RISC-V comprises a processor, a fast interrupt controller, a Caller-save type general-purpose register, and a hardware memory area; the hardware memory area is used for storing a value of the Caller-save type general-purpose register during an interrupt response; and the fast interrupt controller is used for storing the value of the Caller-save type general-purpose register into the hardware memory area, or loading back a content from the hardware memory area into the Caller-save type general-purpose register, and further storing a value of a control and status register set into the hardware memory area when a nested interrupt occurs; which improve an interrupt handling speed of a RISC-V architecture processor, simplify the program development difficulty, expand an application field of the RISC-V as a core single chip microcomputer, and particularly have a wide prospect in the embedded application field.

An apparatus and method for scalable interrupt reporting. For example, one embodiment of an apparatus comprises: a host processor to execute one or more processes having a corresponding one or more process contexts associated therewith; and a graphics processing engine to, upon initiating execution of a first process, determine a current process context associated with the first process including a first pointer to a first system memory region to store an interrupt status, a second pointer to a second system memory region to store interrupt enable and/or interrupt mask data for one or more interrupt events, and address/data values associated with a message signaled interrupt (MSI); the graphics processing engine, in response to an interrupt event, to evaluate the interrupt enable data from the second system memory region to determine whether the interrupt event is enabled, to report the interrupt event, if enabled, by writing a specified value to the first system memory region identified by the first pointer, and to generate a first MSI corresponding to the interrupt event by writing the MSI address/data values to an output accessible by the host processor.

A multi-processor system with a distributed mailbox architecture and a communication method thereof are provided. The multi-processor system comprises a plurality of processors, each of the processors is correspondingly configured with an exclusive mailbox and an exclusive channel, and the communication method comprises the following steps. When a first processor of the processors needs to communicate with a second processor, the first processor writes data into the exclusive mailbox of the second processor through a public bus; and when the writing of the data has completed, the exclusive mailbox of the second processor sends an interrupt signal to the second processor, after receiving the interrupt signal, the second processor reads the data in the exclusive mailbox through the corresponding exclusive channel.