Abstract: Digital multiprocessor methods and apparatus comprise a plurality of processors, including a first processor for normally processing an instruction stream including instructions from a first instruction source. At least one of the processors can transmit inserted-instructions to the first processor. Inserted-instructions are executed by the first processor in the same manner as, and without affecting the sequence of, instructions from the first instruction source. The first instruction source can be a memory element, including an instruction cache element for storing digital values representative of instructions and program steps, or an execution unit (CEU) which asserts signals to the instruction cache element to cause instructions to be transmitted to the CEU. The processors include input/output (I/O) processors having direct memory access (DMA) insert elements, which respond to a peripheral device to generate DMA inserted-instructions.

Abstract: A digital data communications apparatus includes first and second processing groups, each made up of a plurality of processing cells interconnected by an associated bus. An element (RRC) transfers information packets generated by the processing cells between the first and second processing groups. The RRC includes an input for receiving packets from the bus of the first processing group, as well as first and second outputs for outputting packets to the buses of the first and second groups, respectively. A control element routes packets received at the input to a selected one of the outputs based upon a prior history of routings of the datum referenced in that information packet (or requests for that data) between said first and second processing groups.

Abstract: A switch is provided for selectively routing digital information packets received from at least first and second external sources to at least first and second external destinations. At least one of the first sources generates an information packet including a datum, or a request therefore, and a corresponding descriptor. First and second routing interconnects have inputs for receiving packets from respective sources and outputs for transmitting packets to respective destinations. The interconnects are also coupled for transferring packets between one another. Directories within the interconnects store descriptors corresponding to data associated with the first destination, as well as requests routed from the other interconnect. A controller routes packets based on the correspondence, or lack thereof, between the descriptor in that packet and an entry signal allocated to corresponding directory.

Abstract: A method of assigning priorities and resolving bus contention in a distributed computer system is disclosed. Each system node is assigned an identifier. Priorities are reassigned at each change in bus access such that the node that most recently had access to the bus is assigned the lowest priority with the node having the next identifier in sequence being assigned the highest priority and all other nodes assigned priority in accordance with their identifier's position in the sequence. The identifiers are logically treated as organized in a circular fashion such that the lowest node identifier is considered to come next in the sequence after the highest node identifier.

Abstract: Apparatus and method is disclosed for controlling the timing of the addressing, fetching and executing of microinstructions in a data processing system such that delayed sequencing microinstructions, stretched delayed sequencing microinstructions and immediate sequencing microinstructions may be intermixed in the microinstruction stream. Circuitry is provided to determine the type of sequencing specified for each microinstruction and control the generation of the execution cycle signal and the microinstruction address clocking signal such that these signals occur in the appropriate time sequence to accomplish the specified sequencing.

Abstract: A data processing system in which macroinstructions are decoded to provide a sequence of microinstructions comprising one or more microroutines. If a fault condition occurs, the currently executing microinstruction of a sequence thereof is interrupted, while the fault is being handled. When the fault has been resolved, execution of the interrupted microinstruction resumes. If the fault cannot be resolved the sequence of microinstructions is permanently aborted. The process of interrupting the sequence and resuming operation at the interrupted microinstruction is essentially invisible to the microprogram.

Abstract: A data processing system in which macroinstructions are decoded to provide a sequence of microinstructions comprising one or more microroutines. A stack storage means stores data for use in such microroutines. The final microinstruction of the microroutines is a request to retrieve or remove data from the stack. When no data is present therein (the stack is empty) a new macroinstruction is requested and when data is present in the stack the microroutine returns to another mircoroutine in which it is acting as a micro-subsroutine to permit continuation of the other microroutine.

Abstract: Method and apparatus for improving instruction decoding in a microcode-controlled digital computer system. The microinstruction sequences are made simple and compact enough that sufficient complexity is required in the instruction decoding logic that it is feasible to custom-configure a gate array to perform instruction decoding. The resultant gate array, by virtue of being embodied in a single integrated circuit, is extremely fast and compact and has low power requirements.

Abstract: A data processing system having separate kernel, vertical and horizontal microcode, separate loading of vertical microcode and a permanently resident kernel microcode, and a soft console with dual levels of capability. The system includes a processor having dual ALC and microcode processors, and an instruction processor. Also included are a processor incorporating a multifunction processor memory, a malfunction nibble shifter, and a high speed look-aside memory control.

Abstract: A data processing system having separate kernel, vertical and horizontal microcode, separate loading of vertical microcode and a permanently resident kernel microcode, and a soft console with dual levels of capability. The system includes a processor having dual ALC and microcode processors, and an instruction processor. Also included are a processor incorporating a multifunction processor memory, a multifunction nibble shifter, and a high speed look-aside memory control. Adaptive microcode control means 272 are disclosed in which microinstruction sequencing is a function 273 of the current microinstruction and current machine state.

Abstract: A data processing uses instructions which may refer to operands in main memory by either physical or logical addresses. The central processor has an internal memory organized as two portions. The first portion provides a scratchpad memory function for the central processor and the second portion is responsive to logical addresses to provide corresponding physical addresses.

Abstract: A data processing system which handles thirty-two bit logical addresses which can be derived from either sixteen bit logical addresses or thirty-two bit logical addresses, the latter being translated into physical addresses by unique translation means. The system includes means for decoding macro-instructions of both a basic and an extended instruction set, each macro-instruction containing in itself selected bit patterns which uniquely identify which type of instruction is to be decoded. The decoded macro-instructions provide the starting address of one or more micro-instructions, which address is supplied to a unique micro-instruction sequencing unit which appropriately decodes a selected field of each micro-instruction to obtain each successive micro-instruction. The system uses hierarchical memory storage using eight storage segments (rings), access to the rings being controlled in a privileged manner according to different levels of privilege.