Abstract: A circuit arrangement and method utilize existing redundant execution pipelines in a processing unit to execute multiple instances of stability critical instructions in parallel so that the results of the multiple instances of the instructions can be compared for the purpose of detecting errors. For other types of instructions for which fault tolerant or stability critical execution is not required or desired, the redundant execution pipelines are utilized in a more conventional manner, enabling multiple non-stability critical instructions to be concurrently issued to and executed by the redundant execution pipelines. As such, for non-stability critical program code, the performance benefits of having multiple redundant execution units are preserved, yet in the instances where fault tolerant or stability critical execution is desired for certain program code, the redundant execution units may be repurposed to provide greater assurances as to the fault-free execution of such instructions.

Abstract: A floating point execution unit is capable of selectively repurposing a subset of the significand bits in a floating point value for use as additional exponent bits to dynamically provide an extended range for floating point calculations. A significand field of a floating point operand may be considered to include first and second portions, with the first portion capable of being concatenated with the second portion to represent the significand for a floating point value, or, to provide an extended range, being concatenated with the exponent field of the floating point operand to represent the exponent for a floating point value.

Abstract: A floating point execution unit is capable of selectively repurposing one or more adders in an exponent path of the floating point execution unit to perform fixed point addition operations, thereby providing fixed point functionality in the floating point execution unit.

Abstract: Due to the ever expanding number of registers and new instructions in modern microprocessor cores, the address widths present in the instruction encoding continue to widen, and fewer instruction opcodes are available, making it more difficult to add new instructions to existing architectures without resorting to inelegant tricks that have drawbacks such as source destructive operations. The disclosed invention utilizes specialized decode and address calculation hardware that concatenates a fixed number of least significant bits of the instruction address onto the upper address bits of each register address portion contained in the instruction, yielding the full register address, instead of providing the full register address widths for every register used in the instruction. This frees up valuable opcode space for other instructions and avoids compiler complexity. This aligns nicely with how most loops are unrolled in assembly language, where independent operations are near each other in memory.

Abstract: An integrated processor block of the network on a chip is programmable to perform a first function. The integrated processor block includes an inbox to receive incoming packets from other integrated processor blocks of a network on a chip, an outbox to send outgoing packets to the other integrated processor blocks, an on-chip memory, and a memory management unit to enable access to the on-chip memory.

Abstract: A method includes receiving packed data corresponding to pixel components to be processed at a graphics pipeline. The method includes unpacking the packed data to generate floating point numbers that correspond to the pixel components. The method also includes routing each of the floating point numbers to a separate lane of the graphics pipeline. Each of the floating point numbers are to be processed by multiplier units of the graphics pipeline.

Abstract: A circuit arrangement and method utilize existing redundant execution pipelines in a processing unit to execute multiple instances of stability critical instructions in parallel so that the results of the multiple instances of the instructions can be compared for the purpose of detecting errors. For other types of instructions for which fault tolerant or stability critical execution is not required or desired, the redundant execution pipelines are utilized in a more conventional manner, enabling multiple non-stability critical instructions to be concurrently issued to and executed by the redundant execution pipelines. As such, for non-stability critical program code, the performance benefits of having multiple redundant execution units are preserved, yet in the instances where fault tolerant or stability critical execution is desired for certain program code, the redundant execution units may be repurposed to provide greater assurances as to the fault-free execution of such instructions.

Abstract: A circuit arrangement and method support data dependent instruction decoding, whereby instructions are decoded, in part, using decode data that is stored in operand registers identified by such instructions. An instruction may include an opcode and at least one operand that identifies a register. During execution of the instruction, the instruction is first decoded using the opcode, and then decode data stored in the operand register is retrieved and used to further decode the instruction, e.g., to select from among a plurality of operations or instruction types associated with the same opcode.

Abstract: A pipelined execution unit uses the bubbles that occur during execution to selectively repeat operations performed in one or more stages of a multistage execution pipeline to verify the results of such operations during otherwise unused execution cycles for the execution pipeline. Whenever a bubble follows a particular instruction within an execution pipeline, the result of an operation that is performed for that instruction by a particular stage of the execution pipeline may be stored, and the operation may be repeated by the stage in a subsequent execution cycle in which no productive operation would otherwise be performed due to the presence of the bubble. The results of the operations may then be compared and used to either verify the original result or identify a potential error in the execution of the instruction.

Abstract: Embodiments of the present invention provide methods, a module, and a system for calculating a credit limit for an interface capable of receiving multiple packets simultaneously. Generally, the multiple packets are simultaneously received at an interface on the second device, each packet being one of a plurality of packet types, and a flow control credit limit to be transmitted to the first device is adjusted based on the combination of packet types of the simultaneously received packets.

Abstract: A circuit arrangement and method utilize thread pair context caching, where a pair of hardware threads in a multithreaded processor, which are each capable of executing a process, are effectively paired together, at least temporarily, to perform context switching operations such as context save and/or load operations in advance of context switches performed in one or more of such paired hardware threads. By doing so, the overall latency of a context switch, where both the context for a process being switched from must be saved, and the context for the process being switched to must be loaded, may be reduced.

Abstract: A circuit arrangement and method utilize thread pair context caching, where a pair of hardware threads in a multithreaded processor, which are each capable of executing a process, are effectively paired together, at least temporarily, to perform context switching operations such as context save and/or load operations in advance of context switches performed in one or more of such paired hardware threads. By doing so, the overall latency of a context switch, where both the context for a process being switched from must be saved, and the context for the process being switched to must be loaded, may be reduced.

Abstract: A pipelined execution unit uses the bubbles that occur during execution to selectively repeat operations performed in one or more stages of a multistage execution pipeline to verify the results of such operations during otherwise unused execution cycles for the execution pipeline. Whenever a bubble follows a particular instruction within an execution pipeline, the result of an operation that is performed for that instruction by a particular stage of the execution pipeline may be stored, and the operation may be repeated by the stage in a subsequent execution cycle in which no productive operation would otherwise be performed due to the presence of the bubble. The results of the operations may then be compared and used to either verify the original result or identify a potential error in the execution of the instruction.

Abstract: A circuit arrangement and method support data dependent instruction decoding, whereby instructions are decoded, in part, using decode data that is stored in operand registers identified by such instructions. An instruction may include an opcode and at least one operand that identifies a register. During execution of the instruction, the instruction is first decoded using the opcode, and then decode data stored in the operand register is retrieved and used to further decode the instruction, e.g., to select from among a plurality of operations or instruction types associated with the same opcode.

Abstract: A floating point execution unit is capable of selectively repurposing a subset of the significand bits in a floating point value for use as additional exponent bits to dynamically provide an extended range for floating point calculations. A significand field of a floating point operand may be considered to include first and second portions, with the first portion capable of being concatenated with the second portion to represent the significand for a floating point value, or, to provide an extended range, being concatenated with the exponent field of the floating point operand to represent the exponent for a floating point value.

Abstract: Embodiments of the present invention provide methods, a module, and a system for calculating a credit limit for an interface capable of receiving multiple packets simultaneously. Generally, the multiple packets are simultaneously received at an interface on the second device, each packet being one of a plurality of packet types, and a flow control credit limit to be transmitted to the first device is adjusted based on the combination of packet types of the simultaneously received packets.

Abstract: Embodiments of the present invention provide methods, a module, and a system for calculating a credit limit for an interface capable of receiving multiple packets simultaneously. Generally, the multiple packets are simultaneously received at an interface on the second device, each packet being one of a plurality of packet types, and a flow control credit limit to be transmitted to the first device is adjusted based on the combination of packet types of the simultaneously received packets.

Abstract: In a first aspect, a first method is provided. The first method includes the steps of (1) transmitting data on a bus, wherein data is presented on the bus using varying widths; (2) configuring a cyclic redundancy check (CRC) to be performed on the data based on the manner in which the data is presented on the bus; and (3) performing the CRC on the data. Numerous other aspects are provided.

Abstract: In a method of communicating a plurality of parallel data packets from a first data parallel bus to a second parallel data bus, each of the plurality of parallel data packets is separated into a first portion and a second portion. Each first portion is converted into a first serial data stream and each second portion is converted into a second serial data stream. The first serial data stream is transmitted over a first serial data channel and the second serial data stream is transmitted over a second serial data channel. The first serial data stream is converted into a plurality of first received portions and the second serial data stream is converted into a plurality of second received portions. Selected first received portions are combined with corresponding selected second received portions so as to regenerate the plurality of parallel data packets.

Abstract: An apparatus for enabling transmission of parallel data from a first parallel bus to a second parallel bus via a serial data channel includes a first logic element that generates a synchronization character used in a serial data transmission protocol upon detection of a parallel synchronization packet. A serializer converts data from the first logic element into a serial data stream. A de-serializer converts the serial data stream into a plurality of parallel data packets. A second logic element detects the synchronization character and converts the synchronization character into a parallel synchronization packet.