Abstract: Low power architecture features and techniques are provided in a scalable array indirect VLIW processor. These features and techniques include power control of a reconfigurable register file, conditional power control of multi-cycle operations and indirect VLIW utilization, and power control of VLIW-based vector processing using the ManArray register file indexing mechanism. These techniques are applicable to all processing elements (PEs) and the array controller sequence processor (SP) to provide substantial power savings.

Abstract: An array processor includes processing elements (00, 01, 02, 03, 10, 11, 12, 13, 20, 21, 22, 23, 30, 31, 32, 33) arranged in clusters (e.g., 44, 46, 48, 50) to form a rectangular array (40). Inter-cluster communication paths (88) are mutually exclusive. Due to the mutual exclusivity of the data paths, communications between the processing elements of each cluster may be combined in a single inter-cluster path, thus eliminating half the wiring required for the path. The length of the longest communication path is not directly determined by the overall dimension of the array, as in conventional torus arrays. Rather the longest communications path is limited by the inter-cluster spacing. Transpose elements of an N×N torus may be combined in clusters and communicate with one another through intra-cluster communications paths. Transpose operation latency is eliminated in this approach. Each PE may have a single transmit port (35) and a single receive port (37).

Abstract: A computing architecture and software techniques are described which modifies the basic sequential instruction fetching mechanism of a processor by separating a program's control flow from its functional execution flow. A compiled sequential HLL program's static control structures are analyzed and a separate program based on its own unique instructions is created that primarily generates addresses for the selection of functional execution instructions. The original program is now represented by an instruction fetch program and a set of function/logic execution instructions. This basic split allows multiple instruction addresses to be generated in parallel to access multiple instruction memories. These multiple instruction memories contain only the function/logic instructions of the program and no control structure operations such as branches or calls. All the original program's control instructions are split from the original program and used to create the instruction addressing program.

Abstract: An array processor includes processing elements (00, 01, 02, 03, 10, 11, 12, 13, 20, 21, 23, 30, 31, 32, 33) arranged in clusters (e.g., 44, 46, 48, 50) to form a rectangular array (40). Inter-cluster communication paths (88) are mutually exclusive. Due to the mutual exclusivity of the data paths, communications between the processing elements of each cluster may be combined in a single inter-cluster path, thus eliminating half the wiring required for the path. The length of the longest communication path is not directly determined by the overall dimension of the array, as in conventional torus arrays. Rather, the longest communications path is limited by the inter-cluster spacing. Transpose elements of an N×N torts may be combined in clusters and communicate with one another through intra-cluster communications paths. Transpose operation latency is eliminated in this approach. Each PE may have a single transmit port (35) and a single receive port (37).

Abstract: Efficient computation of complex long multiplication results and an efficient calculation of a covariance matrix are described. A parallel array VLIW digital signal processor is employed along with specialized complex long multiplication instructions and communication operations between the processing elements which are overlapped with computation to provide very high performance operation. Successive iterations of a loop of tightly packed VLIWs may be used allowing the complex multiplication pipeline hardware to be efficiently used.

Abstract: A shared memory network for communicating between processors using store and load instructions is described. A new processor architecture which may be used with the shared memory network is also described that uses arithmetic/logic instructions that do not specify any source operand addresses or target operand addresses. The source operands and target operands for arithmetic/logic execution units are provided by independent load instruction operations and independent store instruction operations.

Abstract: A systematic approach to architecture and design of the instruction fetch mechanisms and instruction set architectures in embedded processors is described. This systematic approach allows a relaxing of certain restrictions normally imposed by a fixed-size instruction set architecture (ISA) on design and development of an embedded system. The approach also guarantees highly efficient usage of the available instruction storage which is only bounded by the actual information contents of an application or its entropy. The result of this efficiency increase is a general reduction of the storage requirements, or a compression, of the instruction segment of the original application. An additional feature of this system is the full decoupling of the ISA from the core architecture. This decoupling allows usage of a variable length encoding for any size of the ISA without impacting the physical instruction memory organization or layout and branching mechanism as well as tuning of the execution core to the application.

Abstract: Low power architecture features and techniques are provided in a scalable array indirect VLIW processor. These features and techniques include power control of a reconfigurable register file, conditional power control of multi-cycle operations and indirect VLIW utilization, and power control of VLIW-based vector processing using the ManArray register file indexing mechanism. These techniques are applicable to all processing elements (PEs) and the array controller sequence processor (SP) to provide substantial power savings.

Abstract: A processor with a generalized eventpoint architecture, which is scalable for use in a very long instruction word (VLIW) array processor, such as the manifold array (ManArray) processor is described. In one aspect, generalized processor event (p-event) detection facilities are provided by use of compares to check if an instruction address, a data memory address, an instruction, a data value, arithmetic-condition flags, or other processor change of state eventpoint has occurred. In another aspect, generalized processor action (p-action) facilities are provided to cause a change in the program flow by loading the program counter with a new instruction address, generate an interrupt, signal a semaphore, log or count the p-event, time stamp the event, initiate a background operation, or to cause other p-actions to occur.

Abstract: Techniques are described for decoupling fetching of an instruction stored in a main program memory from earliest execution of the instruction. An indirect execution method and program instructions to support such execution are addressed. In addition, an improved indirect deferred execution processor (DXP) VLIW architecture is described which supports a scalable array of memory centric processor elements that do not require local load and store units.

Abstract: Hardware and software techniques for interrupt detection and response in a scalable pipelined array processor environment are described. Utilizing these techniques, a sequential program execution model with interrupts can be maintained in a highly parallel scalable pipelined array processing containing multiple processing elements and distributed memories and register files. When an interrupt occurs, interface signals are provided to all PEs to support independent interrupt operations in each PE dependent upon the local PE instruction sequence prior to the interrupt. Processing/element exception interrupts are supported and low latency interrupt processing is also provided for embedded systems where real time signal processing is required. Further, a hierarchical interrupt structure is used allowing a generalized debug approach using debut interrupts and a dynamic debut monitor mechanism.