Abstract: IEEE 1394 bus interface circuit 15X comprises a physical layer LSI 37 connected to an IEEE 1394 bus 14, a data capture circuit 22X connected to the physical layer LSI 37 through signal lines to capture data on the signal lines for data analysis, and a coupler (a plug or a socket) 38 to be coupled to a coupler (a socket or a plug) 39 to which a physical layer LSI of an IEEE 1394 bus interface 10 is attached in actual use. With engaging the couplers 39 and 38 to each other, data transmitted between nodes 10 and 13 are captured by the data capture circuit 22X and analyzed in an IEEE 1394 bus analysis apparatus 16. In another IEEE 1394 bus interface circuit, a link power status signal provided to the physical layer circuit from the link layer circuit is fixedly set low, whereby the physical layer circuit is made to function as a repeater, and data received by the physical layer circuit are captured by the link layer circuit and analyzed in the IEEE 1394 bus analysis apparatus.
Abstract: A server computer searches for at least one printing-service proving store based on printing-condition information sent form an information terminal, and sends information representing the searched printing-service providing store to the information terminal. After a user selects one printer device based on the information representing the at least one printing-service providing store, the information terminal sends document data to be printed to the server computer. The server computer sends printing data to be printed to the user-selected printer device.
Abstract: A method and apparatus for determining position using a handheld personal computer. A cradle is disclosed that that is adapted to couple to a handheld personal computer. In one embodiment, the cradle includes projecting members that capture the handheld personal computer and hold it securely in place. The cradle includes a position determining system that is adapted to determine position. Upon coupling the cradle to a handheld personal computer, the cradle is operable to determine position. Once position is determined, the determined position is displayed on the display of the handheld personal computer. The display can include a display of a moving map and an icon indicating the current position relative to the map. All required hardware and software for storing the map database and for determining position are included within the cradle.
Abstract: A cooperative disk cache management and rotational positioning optimization (RPO) method for a data storage device, such as a disk drive, makes cache decisions that decrease the total access times for all data. The cache memory provides temporary storage for data either to be written to disk or that has been read from disk. Data access times from cache are significantly lower than data access times from the storage device, and it is advantageous to store in cache data that is likely to be referenced again. For each data block that is a candidate to store in cache, a cost function is calculated and compared with analogous cost functions for data already in cache. The data having the lowest cost function is removed from cache and replaced with data having a higher cost function.
Type:
Grant
Filed:
September 14, 2000
Date of Patent:
July 9, 2002
Assignee:
International Business Machines Corporation
Abstract: An electronic system and method that maintains time dependencies and ordering constraints in an electronic system. A timing controller utilizes a representative bit to track timing dependencies associated with information and ensures the information is communicated and processed in an order that preserves the timing dependencies as the information is converted from parallel to parallel or parallel to serial operations. The present invention tracks the order in which information is loaded in a electronic hardware component and ensures that the information loaded into the electronic hardware component at a particular time is processed without interruption by information loaded at a different time.
Abstract: One aspect of the present invention provides a packer-unpacker (PUP) for a digital serial interface which allows a plurality of processors to access time slot registers of a serial data stream relating to the digital serial interface. A configuration register is maintained either by one of the plurality of processors or by each of the processors to arbitrate access to the individual time slot registers. Another aspect of the invention allows one or more processors to efficiently access and/or write more bits to a resource such as a time slot register than the width of the processor's respective data bus allows. Extra bits registers are maintained for at least one of the read and write direction data busses. The extra bits correspond to the least significant bits conventionally ignored in changing from a data bus of one width to a data bus of a narrower width. The extra bits in the write direction are accessed, e.g.
Abstract: Disclosed is a system, method, and program for selecting an input/output (I/O) command in a queue of I/O commands. Each I/O command operates within a range of addressable locations on a storage medium. Each addressable location is defined according to a sector number and track number. The program makes use of a plurality of buckets, wherein each bucket represents a range of consecutive sector numbers. Each queued I/O command is associated with a bucket such that a sector number of an addressable location in which an I/O command operates is within the range of sectors comprising the associated bucket. A reference position is determined. A selection routine is then executed to select an I/O command. The selection routine selects a bucket including at least one I/O command and selects an I/O command within the selected bucket. The routine then determines whether the selected I/O command meets a selection criteria. The routine indicates the selected I/O command as the I/O command to process.
Type:
Grant
Filed:
March 31, 1999
Date of Patent:
August 7, 2001
Assignee:
International Business Machines Corporation
Abstract: A peripheral device connecting system with priority arbitration includes a connection matrix connected to a plurality of peripheral devices capable of transmitting a signal to be arbitrated, e.g., an interrupt enable signal. The connection matrix includes first and second connection matrices connected to each other through a plurality of logic gates having a progressive number of inputs for transmitting in parallel a plurality of signals to be arbitrated. A connection matrix for a microcontroller-emulating chip includes a peripheral device connecting system with priority arbitration.
Abstract: A method for selecting a next command to execute from a set of SCSI commands where the commands are gracefully aged and performance of a disk drive is improved. An execution threshold age, a pool threshold age, and an age threshold age are used to determine what command is executed next. A mechanical time delay is calculated for a command based on the time required to position the read/write head over the data location requested in each command. A command age is calculated based on a current time and the time the command was received from the host. The command age is checked against the execution threshold age and pool threshold age. Any commands that have aged beyond the execution threshold age are executed. If the oldest command has aged beyond the age threshold age, then any command that has both aged beyond the pool threshold age and has the smallest mechanical time delay is executed, otherwise the command with the smallest mechanical time delay is executed.
Abstract: A method for accessing a shared resource is provided. An assigned usage rate is received from a resource coordinator and a desired usage rate is determined. When it is determined that the desired usage rate is higher than the assigned usage rate, a shared resource may be accessed at an enhanced usage rate if a usage reserve has been accumulated. When a shared resource is accessed at an enhanced usage rate, the usage reserve is decremented by an amount based on a difference between the enhanced usage rate and the assigned rate. When there is no usage reserve accumulated, access to the shared resource is limited to the assigned usage rate. When the desired usage rate is not higher than the assigned usage rate, a shared resource is accessed at the desired usage rate. When the desired usage rate is less then the assigned usage rate, the usage reserve is accumulated up to a reserve maximum. The reserve maximum may be based on configuration data.
Abstract: A communications interface is provided for apparatus such as a desktop computer or printer. The communications interface provides both for connection to a network and connection to a local device that may be a portable computer, the two connections operating according to different protocol schemes. The communications interface permits the local device to communicate both with the main processing functionality of the apparatus and with the network. By providing standby power to the communications interface when the apparatus is switched off, the local device can continue to communicate with remote devices over the network even when the apparatus is off.
Abstract: A method, apparatus, and article of manufacture for generating signals using a Universal Serial Bus (USB) host controller and USB keyboard. Data generated by the keyboard is marked as being used with an operating system which responds to keyboard generated interrupts and which reads keyboard data stored in a register. The marked data is detected after it is received from the keyboard and is transferred to a register. An interrupt to a central processing unit (CPU) is then generated in response to the marked data being transferred to the register.