Abstract: A multithreaded processor device is disclosed and includes a first program thread and second program thread. The second program thread is execution linked to the first program thread in a lock step manner. As such, when the first program thread experiences a stall event, the second program thread is instructed to perform a no operation instruction in order to keep the second program thread execution linked to the first program thread. Also, the second program thread performs a no operation instruction during each clock cycle that the first program thread is stalled due to the stall event. When the first program thread performs a first successful operation after the stall event, the second program thread restarts normal execution.

Abstract: A method and system to indicate which page within a software-managed page table triggers an exception within a microprocessor, such as, for example, a digital signal processor, wherein a software-managed translation lookaside buffer (TLB) module receives a virtual address produced by an instruction within a Very Long Instruction Word (VLIW) packet, such as, for example, a fetch instruction, and further compares the virtual address to each stored TLB entry. If a match exists, then the TLB module outputs a corresponding mapped physical address for the instruction. Otherwise, if the VLIW packet spans two pages, where a first page is present as a TLB entry within the TLB module and the second page is missing from the stored TLB entries, an indication bit within a data field of a control register is set to identify the TLB miss exception to a software management unit.

Abstract: A system and method to execute a linear feedback-shift instruction is disclosed. In a particular embodiment the method includes executing an instruction at a processor by receiving source data and executing a bitwise logical operation on the source data and on reference data to generate intermediate data. The method further includes determining a parity value of the intermediate data, shifting the source data, and entering the parity value of the intermediate data into a data field of the shifted source data to produce resultant data.

Abstract: An instruction memory unit comprises a first memory structure operable to store program instructions, and a second memory structure operable to store program instructions fetched from the first memory structure, and to issue stored program instructions for execution. The second memory structure is operable to identify a repeated issuance of a forward program redirect construct, and issue a next program instruction already stored in the second memory structure if a resolution of the forward branching instruction is identical to a last resolution of the same. The second memory structure is further operable to issue a backward program redirect construct, determine whether a target instruction is stored in the second memory structure, issue the target instruction if the target instruction is stored in the second memory structure, and fetch the target instruction from the first memory structure if the target instruction is not stored in the second memory structure.

Abstract: A processor device is disclosed that includes a register file with a combined condition code register for scalar and vector operations. The processor device utilizes the combined condition code register for scalar and vector operations. Further, a compare operation can store resulting bits in the combined condition code register and a conditional operation can utilize the combined condition code register bits for evaluating a condition.

Abstract: Techniques for processing transmissions in a communications (e.g., CDMA) system. A method and system for issuing and executing mixed architecture instructions in a multiple-issue digital signal processor receives in a mixed instruction listing a plurality of digital signal processor instructions. The plurality of digital signal processor instructions includes a plurality of parallel executable instructions (e.g., VLIW instructions or instruction packets) mixed among a plurality of series executable instructions (e.g., superscalar instructions). The series executable instructions are associated by various instruction dependencies. The method and system further identify in the mixed instruction listing the plurality of parallel executable instructions. Once identified, the parallel executable instructions are first executed in parallel irrespective of any such instruction's relative order in the mixed instruction listing.

Abstract: Techniques for processing transmissions in a communications (e.g., CDMA) system. The method and system encode and process instructions of mixed lengths (e.g., 16 bits and 32 bits) and instruction packets including instructions of mixed lengths. This includes encoding a plurality of instructions of a first length and a plurality of instructions of a second length. The method and system encode a header having at least one instruction length bit. The instruction bit distinguishes between instructions of the first length and instructions of the second length for an associated DSP to process in a mixed stream. The method and system distinguish between the instructions of the first length and the instructions of the second length according to the contents of the instruction length bits. The header further includes bits for distinguishing between instructions of varying lengths in an instruction packet.

Abstract: An interleaved multithreading pipeline operating method comprises reading an instruction packet containing at least two instructions, steering a first instruction of the instruction packet to a first execution unit for execution and generating a first result, steering a second instruction of the instruction packet to a second execution unit for execution using the first result and generating a second result, and storing the second result.

Abstract: A method and system to combine multiple register units within a microprocessor, such as, for example, a digital signal processor, are described. A first register unit and a second register unit are retrieved from a register file structure within a processing unit, the first register unit and the second register unit being non-adjacently located within the register file structure. The first register unit and the second register unit are further combined during execution of a single instruction to form a resulting register unit. Finally, the resulting register unit is stored within the register file structure for further processing. Alternatively, a first half word unit from the first register unit and a second half word unit from the second register unit are retrieved. The first half word unit and the second half word unit are further input into corresponding high and low portions of a resulting register unit to form the resulting register unit during execution of a single instruction.

Abstract: A shared translation look-aside buffer method comprises saving data stored in a first selected set of registers to a predetermined section of a thread-specific area in memory upon encountering an exception/interrupt, re-enabling exceptions and optionally interrupts, addressing a cause of the exception/interrupt while safely permitting another exception, and restoring the saved data to the first selected set of registers.

Abstract: A processor is operable to carry out a method that comprises accessing a first register based on a program instruction and obtaining a first register-out value, accessing a second register based on the first register-out value and obtaining a second register-out value, and storing the second register-out value into a third register based on the program instruction. The processor is further operable to carry out a method that comprises accessing a first register based on a program instruction and obtaining a first register-out value, accessing a second register based on the program instruction and obtaining a second register-out value, and storing the first register-out value into a third register based on the second register-out value.

Abstract: A multi-threaded processor is disclosed that includes a sequencer adapted to provide instructions associated with one or more threads of a multi-threaded processor. The sequencer includes an interrupt controller adapted to receive one or more interrupts and to selectively allow a first thread of the one or more threads to service at least one interrupt. The interrupt controller includes logic to preclude a second thread of the one or more threads from responding to the at least one interrupt.

Abstract: A processor device is disclosed that includes a register file with a combined condition code register for scalar and vector operations. The processor device utilizes the combined condition code register for scalar and vector operations. Further, a compare operation can store resulting bits in the combined condition code register and a conditional operation can utilize the combined condition code register bits for evaluating a condition.

Abstract: A method and system to perform shifting and rounding operations within a microprocessor, such as, for example, a digital signal processor, during execution of a single instruction are described. An instruction to shift and round data within a source register unit of a register file structure is received within a processing unit. The instruction includes a shifting bit value indicating the bit amount for a right shift operation and is subsequently executed to shift data within the source register unit to the right by an encoded bit value, calculated by subtracting a single bit from the shifting bit value contained within the instruction. A predetermined bit extension is further inserted within the vacated bit positions adjacent to the shifted data. Subsequently, an addition operation is performed on the shifted data and a unitary integer value is added to the shifted data to obtain resulting data.

Abstract: A method and system to indicate which page within a software-managed page table triggers an exception within a microprocessor, such as, for example, a digital signal processor, wherein a software-managed translation lookaside buffer (TLB) module receives a virtual address produced by an instruction within a Very Long Instruction Word (VLIW) packet, such as, for example, a fetch instruction, and further compares the virtual address to each stored TLB entry. If a match exists, then the TLB module outputs a corresponding mapped physical address for the instruction. Otherwise, if the VLIW packet spans two pages, where a first page is present as a TLB entry within the TLB module and the second page is missing from the stored TLB entries, an indication bit within a data field of a control register is set to identify the TLB miss exception to a software management unit.

Abstract: Methods and apparatus for encoding information regarding a hardware loop of a set of packets is provided, each packet (400) containing instructions. The information is encoded into one or more bits of at least one instruction (300) in the set of packets. The information may indicate whether a packet is or is not an end packet of the loop. Information regarding two hardware loops may be encoded where information regarding the first loop is encoded into an instruction at a first position in each packet and information regarding the second loop is encoded into an instruction at a second position in each packet. End instruction information may be encoded into an instruction not having encoded loop information at the same bit positions reserved for the encoded loop information, the end instruction information indicating whether an instruction is the last instruction of a packet and the length of a packet.

Abstract: Techniques for processing digital signals for a variety of applications, including in a communications (e.g., CDMA) system. A pointer location within a circular buffer is determined by establishing a length of the circular buffer, a start address that is aligned to a power of 2, and an end address located distant from the start address by the length and less than a power of 2 greater than the length. The method and system determine a current pointer location for an address within the circular buffer, a stride value of bits between the start address and the end address, a new pointer location within the circular buffer that is shifted from the current pointer location by the number of bits of the stride value. An adjusted pointer location is within the circular buffer by an arithmetic operation of the new pointer location with the length.

Abstract: A multithreaded processor device is disclosed and includes a processor that is configured to execute a plurality of executable program threads and a mode control register. The mode control register includes a first data field to control a first execution mode of a first of the plurality of executable program threads and a second data field to control a second execution mode of a second of the plurality of executable program threads. In a particular embodiment, the first execution mode is a run mode and the second execution mode is a low power mode.

Abstract: A shared translation look-aside buffer method comprises saving data stored in a first selected set of registers to a predetermined section of a thread-specific area in memory upon encountering an exception/interrupt, re-enabling exceptions and optionally interrupts, addressing a cause of the exception/interrupt while safely permitting another exception, and restoring the saved data to the first selected set of registers.

Abstract: A processor device is disclosed and includes a memory and a sequencer that is responsive to the memory. The sequencer supports very long instruction word (VLIW) type instructions and at least one VLIW instruction packet uses a number of operands during execution. The processor device further includes a plurality of instruction execution units responsive to the sequencer and a plurality of register files. Each of the plurality of register files includes a plurality of registers and the plurality of register files are coupled to the plurality of instruction execution units. Further, each of the plurality of register files includes a number of data read ports and the number of data read ports of each of the plurality of register files is less than the number of operands used by the at least one VLIW instruction packet.