Abstract: Multiple numbers of "sets" of sender-receiver units operate concurrently to transfer blocks of data. The number of blocks to be transferred in each set is predetermined by a main host computer which registers the number-of-blocks-to-be-transferred into a protocol-controller in each set of sender-receiver units. An associated data feeder control system monitors the number of data blocks residing in a buffer memory, which has dedicated storage for each sender-receiver unit, and will only permit data block transfer to receiver units only to the amount presently available in the buffer memory until, eventually, the predetermined number of data blocks, for each set, is transferred to completion.

Abstract: A diagnostic protocol and display system wherein the cable bus output of a computer to a printer is sensed to select coded error data out of the output stream in order to activate a visual display of coded error data for benefit of the human operator.

Abstract: A multi-cache memory system resides on-chip with a system interface to external memory. A general cache memory holds frequently used data and OPCODES for delivery to a processor in one clock cycle. A microcode cache holds frequently used microcode instruction words for delivery to the processor in one clock cycle. Both general and microcode cache memories operate to replace less frequently used OPCODES, data words, and microcode instruction words, with more frequently used words.

Abstract: A plurality of digital modules on a Futurebus Plus common system bus means in a network are connected by the Futurebus Plus system bus for transfer of data between modules. A sending module (master) transmits address and message data on the bus to a receiving module (slave). Each module provides an interface having a Longitudinal Redundancy Checker such that the sending module transmits a first check word to the receiving module which generates a second check-word. If these check words match, then the data is accepted as good. Thus, the network can work continuously using the system bus even while new digital modules are inserted onto the system bus or detached from the system bus.

Abstract: A system for equal utilization of blocks of flash memory whereby a processor using algorithmic software functions to sort the usage-value of each block of flash memory so that the system will select the least-used memory block for the next cycle of memory usage. The described system provides direct and immediate access of flash memory to the microprocessor without any intermediate modules or vias which would delay that access. Further, a minimal amount of overhead header information is only required for each flash memory block thus allowing greater areas of memory usage for instructional code data.

Abstract: A system and circuitry is provided by which certain selected embedded pins of an integrated circuit gate array may be provided with dual functions, that is to say, they may act either as receivers of an externally sourced input signal or as transmitters of an internally generated output signal. Each selected input/output pin is controlled by an associated flip-flop residing in a chain of flip-flops so that an associated flip-flop will determine the condition of two buffer-drivers attached to each input/output pin. While the first buffer-driver is tri-stated (disabled), then the embedded pin operates as an input receiving function. When the first buffer-driver is enabled, the embedded I/O pin operates as the conveyer of an output signal from the internal output logic.

Abstract: A method and implementation is supplied for the synchronous loading and integrity checking of registers located in two different integrated circuit chips. Thus in a computer system having cache memory where the cache memory is sliced into two portions, one of which holds even addresses and the other of which holds odd addresses, there is provided two individual chips each of which has a program word address register which is loaded at the exact same period of time and which is additionally incremented in both cases at the exact same period of time. Further means are provided for checking the integrity of the program word address registers in the first slice and the second slice of the cache in order to insure that they are coherent, or if not coherent, then a disable signal will prevent usage of the address data involved.

Abstract: A single chip data path gate array interface links a central processing unit, operating at a first clock rate and single word protocol, to dual system busses operating at a second clock rate and multiple-word protocol. The data path interface holds command, data and message registers, controlled by external logic, in an input channel pathway and an output channel pathway. The interface chip is basically limited to registers and multiplexers making it flexible for use in different architectures such as both Store-Through and Non-Store-Through cache protocols. In addition, such a simplified chip is simple to fabricate and to maintain free of defects.

Abstract: A processor cache memory system utilizes separate cache controllers for independently managing even and odd input address requests with the even and odd address requests being mapped into the respective controllers. Each cache controller includes tag RAM for storing address tags, including a field for storing the least significant address bit, so that the stored tags distinguish between the odd and even addresses. Upon failure of a cache controller, both the even and odd addresses are directed to the operational controller and the stored least significant bit address tag distinguishes between the odd and even input addresses to appropriately generate HIT/MISS signals. The controllers include block address counter logic for generating respective even and odd invalidation addresses for simultaneously performing invalidation cycles thereon when both controllers are operational.

Abstract: A mini-cache module is added to a computer system to increase throughput or may also be added to enhance the functionality of a general cache memory unit. The mini-cache module refills and stores frequently used data words concurrently during processor operations and provides them to the processor, eliminating the need to access a system bus to main memory. A data queue storage stores a data block of words from main memory and makes them available to requests from the main processor (if the requested address matches an address register block in the mini-cache). If an address "hit" occurs, then the mini-cache will prevent any system bus request to main memory and additionally will monitor the system bus for any "Write" operations which might feasibly change the validity of data in the data storage block of the mini-cache. In this case the data stored in the mini-cache is invalidated and cannot be used by the processor.

Abstract: Control signals are provided for data transfer timing compatibility between two systems or two modules which are not synchronous with each other. Specialized circuitry is provided to ensure timing compatibility in that control signals, transmitted from one system to the other, are handled by interface circuitry which directly transmits the front-end transition and delays the back-end transition so it can be synchronized to the receiving systems clock.

Abstract: An interbus interface module enables storage and transfer of commands, messages and data between parallel a dual system bus operating on a first protocol and a subrequestor bus operating on a second protocol. The interface module serves a first group of requestors, such as multiple processors and main memory, for handling data transfers to and from the subrequestor bus via said dual system buses while also handling data transfers to and from a second group of requestors connected to the subrequestor bus.

Abstract: A buffer memory holding blocks of data received from a main host computer has dedicated portions for data destined for different sets of sender-receiver units. Each sender-receiver unit has a channel bus path to the buffer memory and each channel bus is monitored by an on-the-fly integrity checking circuit.A control processor and associated bus arbitration logic provide signals to a multiplexer so as to allocate equal access periods to each channel bus for connection to the buffer memory. A data feeder control on each transfer channel senses the availability of data block words in each dedicated segment of the buffer memory so that partial transfers of word blocks may occur on minor cycles with subsequent completion of the blocks of data words on a major transfer cycle.

Abstract: A network of digital modules having store-through and non-store-through cache memories, is provided with intercommunication capability by means of two sets of system busses each of which are replicates of each other. The system busses provide a higher throughput by both being available to each of the digital modules so that a requesting digital module can alternately use a second system bus if the first system bus happens to be busy. Failure of one system bus will allocate transmission service to the second operating system bus thus providing redundancy. Alternatively, each of the system busses can be isolated for partitioning the digital modules into two different operating systems which are independent of each other.

Abstract: A method and system for updating the logical address of pointers used by a processor in a paged memory organization. A logical address associative memory provides a cache holding data about a paged segment of data words eliminating the need to fetch the data from main memory. Update index logic and insertion logic operate to update the logical address of an original pointer to indicate the logical next address of new data sought from main memory. The system is specifically designed to expedite the situation where the page referenced by the next address is different from that referenced by the original pointer's address.

Abstract: A dual bus interface module, providing communication between a processor means and/or translation logic means and a set of dual system busses, provides a programmable transmit logic means which enables bus access for data transfer of commands and message transfer requests to destination modules on said system busses in a manner so as to use any available system bus to complete data transfer requests or to report the status of non-completed requests.

Abstract: In a time-shared bus computer system with processors having cache memories, an adjustable invalidation queue for use in the cache memories. The invalidation queue has adjustable upper and lower limit positions that define when the queue is logically full and logically empty, respectively. The queue is flushed down to the lower limit when the contents of the queue attain the upper limit. During the queue flushing operation, WRITE requests on the bus are RETRYed. The computer maintenance system sets the upper and lower limits at system initialization time to optimize system performance under maximum bus traffic conditions.

Abstract: An error logging system where errors are captured on dual system busses operating at a lower clock rate (16 MHz) than the processor which receives the error information. The system functions to substantially reduce the loads on the processor in addition to maximizing the use of the system bus drivers which are pin-constrained. The processor operates at a higher clock rate (32 MHz). Processor commands to read error data from an error log register are synchronized down to the 16 MHz rate, then enabled onto a processor bus after a second synchronization operation back to the higher (32 MHz) rate. Provision is made for identifying several different types of error categories.

Abstract: A programmable timing logic system for enabling access to a first or second bus, of dual system busses, by a central processor and/or a protocol-timing translation logic unit wherein messages may be received from one bus while command/control data is being transmitted to the other bus. Incomplete command cycles are retried a specific number "n" of times, each for a preset predetermined time period of "p" microseconds.

Abstract: A multiported buffer memory system provides access to four external sources which can access data words in any one of four memory modules. The functions of Reading and Writing and status information can occur simultaneously during the course of system cycles so that any one external source can access any one of the multiple memory modules for Reading and Writing operations. Likewise the concept can be expanded to M input/output ports working together with M memory modules without loss of speed and data communication transfer capabilities.