摘要:
There is provided, for use in a processing system containing a plurality of processors coupled to a main memory, a control circuit for perturbing a lock-step sequence of memory requests received from the processors. The control circuit comprises a memory request generator for generating at least one memory request operable to terminate the lock-step sequence of memory requests.
摘要:
A controller is provided, for use in a processing system containing a plurality of processors operable to communicate with a plurality of I/O devices, for directing a first I/O request issued by a first selected one of the plurality of processors to a targeted one of the I/O devices. The controller device comprises a counter for counting a number of retries associated with the first I/O request and comparison circuitry for comparing a count value in the counter with a first predetermined limit, wherein the controller, in response to a determination that the count value in the counter exceeds the first predetermined limit, blocks all other I/O requests issued by the plurality of processors from being directed to the targeted I/O device.
摘要:
There is disclosed a memory control circuit for use in a processing system containing a plurality of processors coupled to a main memory by a common bus. The memory control circuit is adapted for implementing directory-based coherency in the processing system according to a selected coherency algorithm and comprises: 1) monitoring circuitry for detecting coherency corruption in a coherency directory associated with the main memory; and 2) coherency control circuitry responsive to a detection of coherency corruption in the coherency directory for dynamically modifying the selected coherency algorithm, thereby enabling the processing system to shut down in a controlled manner. In some embodiments, the monitoring circuitry further detects possible system coherency failure conditions external to the coherency directory and the coherency control circuitry responds to the detection of a possible system coherency failure condition by dynamically modifying the selected coherency algorithm, thereby enabling the processing system to shut down in a controlled manner.
摘要:
Disclosed is a tubular prosthesis formed by rolling a perforated sheet around a longitudinal axis. Preferably, the prosthesis is self expandable under the radially outwardly directed spring bias of the rolled sheet. The perforations in the sheet are configured to provide throughholes in the wall of the multilayer prosthesis, when the prosthesis is in the implanted diameter within a vessel. The throughholes are configured to facilitate neointimal cell growth, and in a preferred embodiment, to minimize roll bias in the prosthesis as it is expanded from its reduced, insertion diameter to its expanded, implanted diameter. The prosthesis may be used as a graft or a stent.
摘要:
Multiple processor systems are configured to include at least two system or memory buses with at least two processors coupled to each of the system buses, and at least two I/O buses which are coupled to the system buses to provide multiple expansion slots hosting up to a corresponding number of I/O bus agents for the systems at the cost of a single system bus load for each I/O bus. Each of the system and I/O buses are independently arbitrated to define decoupled bus systems for the multiple processor systems of the present invention. Main memory for the systems is made up of at least two memory interleaves, each of which can be simultaneously accessed through the system buses. Each of the I/O buses are interfaced to the system buses by an I/O interface circuit which buffers data written to and read from the main memory or memory interleaves by I/O bus agents.
摘要:
A buffer management scheme for optimally configuring a data buffer within a computer system which includes a plurality of bus masters connected through a Micro Channel bus and the data buffer to a shared resource, such as memory. The scheme decodes unique four-bit Micro Channel arbitration values assigned to the bus masters to retrieve buffer configuration parameters stored within a register file containing different configuration parameters for each bus master. The data buffer is dynamically configured for optimal performance with each bus master having control of the Micro Channel bus in accordance with the parameter data retrieved from the register file.
摘要:
There is provided, for use in a processing system containing a plurality of processors coupled to a main memory, a control circuit for perturbing a lock-step sequence of memory requests received from the processors. The control circuit comprises a memory request generator for generating at least one memory request operable to terminate the lock-step sequence of memory requests.
摘要:
Disclosed is a tubular prosthesis formed by rolling a flexible sheet around a longitudinal axis. Preferably, the prosthesis is self expandable under the radially outwardly directed spring bias of the rolled sheet. Also disclosed are catheters for delivering two or more of the tubular prostheses at a site within a body lumen. Multiple prostheses may be deployed directly against a vessel wall in a single procedure, or may be deployed within a vascular graft to provide support throughout the length of the graft.
摘要:
A multiprocessor computing apparatus including a plurality of processors each having a cache memory and preferably arranged in nodes on a system bus. A first cache coherency providing mechanism coupled to the processors for achieving system level cache coherency. A second cache coherency providing mechanism is also provided. When an error is detected in the first cache coherency providing mechanism, this mechanism is disabled and cache coherency is achieved by the second cache coherency providing mechanism. In a preferred embodiment, the first mechanism includes coherency directories and the second mechanism includes bus snooping.
摘要:
Logic for determining the average latency of pending pipelined and split bus transactions within a computer system including a bus, such as an Intel Pentium Pro or P6 bus, which supports pipelined and split bus transactions. The logic includes a first counter connected to the bus, and containing a TOTAL QUALIFIED CYCLES count value which is incremented on the start of every qualified bus cycle placed on the bus; logic for determining a cycle COUNT-BY-VALUE representing the number of outstanding or pending qualified bus cycles during any bus cycle; and a second counter which is incremented at the start of every qualified bus cycle occurring during the sample period by the number of outstanding qualified bus cycles to provide a TOTAL LATENCY CLOCKS count value. Divider logic is connected to receive the TOTAL QUALIFIED CYCLES count value from the first counter and the TOTAL LATENCY CLOCKS value from the second counter and divide the TOTAL QUALIFIED CYCLES count value into the TOTAL LATENCY CLOCK value to determine the average number of clocks of latency, or average number of pending bus cycles, per qualified bus cycle.