Abstract: A processor configured for real-time transaction processing is disclosed. A processor circuit includes configuration registers that designate a first range of physical memory addresses as reserved for real-time memory requests and a second, non-overlapping range of physical memory addresses that are shared between real-time and non-real-time memory requests. In response to determining that a memory request is associated with an address in the first range, the processor tags the request as a real-time request. The configuration registers may also store information designating portions of one or more cache memories and one or more buffers as being reserved for real-time memory requests. During arbitration, real-time memory requests are given priority over older, non-real-time memory requests.

Abstract: A system and method for efficiently handling maintenance requests among multiple processors. In various embodiments, a given processor of multiple processors receives a maintenance request. If maintenance requests are not currently being blocked, then the given processor determines a type of the maintenance request and updates one or more maintenance type counters based on the type. If one or more counters exceed a threshold, an indication is generated specifying maintenance requests received at a later time are to be held. The received maintenance request is processed. Different types of maintenance requests are used for invalidating entries in the instruction cache, for invalidating entries in a TLB and for synchronizing page table updates. Afterward, software applications continue processing. Forward progress of the software applications is measured using one or more metrics. If forward progress has been achieved, then one or more maintenance type counters are reset.

Abstract: Various embodiments of a method and apparatus for flushing a cache are disclosed. In a system, a cache memory is accessible by an execution circuit. The execution circuit executes instructions and may utilize data and/or instructions stored in the cache. A flush circuit is also coupled to the cache. Responsive to execution of a power down instruction by the execution circuit, the flush circuit performs a cache flush. If a control state is asserted in a control register, the flush circuit generates a dummy event upon completing the cache flush. Responsive to generating the dummy event, a processor core that includes the execution circuit is inhibited from being powered down.

Abstract: A processor and method are disclosed. In one embodiment the processor includes a prefetch buffer that stores macro instructions. The processor also includes a clock circuit that can provide a clock signal for at least some of the functional units within the processor. The processor additionally includes macro instruction decode logic that can determine a class of each macro instruction. The processor also includes a clock management unit that can cause the clock signal to remain in a steady state entering at least one of the units in the processor that do not operate on a current macro instruction being decoded. Finally, the processor also includes at least one instruction decoder unit that can decode the first macro instruction into one or more opcodes.

Abstract: A processor includes a microcode storage comprising a plurality of microcode flows and a decode logic coupled to the microcode storage. The decode logic is configured to receive a first instruction, decode the first instruction into an entry point vector to a first microcode flow in the microcode storage, the entry point vector comprising a first indicator specifying a number of clock cycles associated with the first microcode flow, initiate the microcode storage, wherein the microcode storage inserts microinstructions of the first microcode flow into an instruction queue, count clock cycles after initiating the microcode storage, and decode a second instruction without first receiving a return from the microcode storage, wherein the second instruction is decoded at a particular clock cycle based on the number of clock cycles associated with the first microcode flow.

Abstract: A processor includes a microcode storage comprising a plurality of microcode flows and a decode logic coupled to the microcode storage. The decode logic is configured to receive a first instruction, decode the first instruction into an entry point vector to a first microcode flow in the microcode storage, the entry point vector comprising a first indicator specifying a number of clock cycles associated with the first microcode flow, initiate the microcode storage, wherein the microcode storage inserts microinstructions of the first microcode flow into an instruction queue, count clock cycles after initiating the microcode storage, and decode a second instruction without first receiving a return from the microcode storage, wherein the second instruction is decoded at a particular clock cycle based on the number of clock cycles associated with the first microcode flow.

Abstract: Techniques to increase the consumption rate of raw instruction bytes within an instruction fetch unit. An instruction fetch unit according to embodiments of the present invention may include a prefetch buffer, a set of bypass multiplexers, an array of bypass latches, a byte-block multiplexer, an instruction alignment multiplexer, a predecode cache, and an instruction length decoder. Raw instruction bytes may be steered from the bypass latches into macro-instructions for consumption by the instruction length decoder, which may generate micro-instructions from the macro-instructions. Embodiments of the present invention may de-couple a latency for reading raw instruction bytes from the prefetch buffer from consuming raw instruction bytes by the instruction length decoder.

Abstract: Techniques to increase the consumption rate of raw instruction bytes within an instruction fetch unit. An instruction fetch unit according to embodiments of the present invention may include a prefetch buffer, a set of bypass multiplexers, an array of bypass latches, a byte-block multiplexer, an instruction alignment multiplexer, a predecode cache, and an instruction length decoder. Raw instruction bytes may be steered from the bypass latches into macro-instructions for consumption by the instruction length decoder, which may generate micro-instructions from the macro-instructions. Embodiments of the present invention may de-couple a latency for reading raw instruction bytes from the prefetch buffer from consuming raw instruction bytes by the instruction length decoder.

Abstract: A processor and method are disclosed. In one embodiment the processor includes a prefetch buffer that stores macro instructions. The processor also includes a clock circuit that can provide a clock signal for at least some of the functional units within the processor. The processor additionally includes macro instruction decode logic that can determine a class of each macro instruction. The processor also includes a clock management unit that can cause the clock signal to remain in a steady state entering at least one of the units in the processor that do not operate on a current macro instruction being decoded. Finally, the processor also includes at least one instruction decoder unit that can decode the first macro instruction into one or more opcodes.