Abstract: A flexible and efficient bulk micromachining method for fabricating a novel microstructure that is bounded by substantially planar surfaces meeting only at substantially right angle corner features. The novel microstructure of the present invention is useful as a spacer in assembly processes where high accuracy is required, such as precise positioning of optical fibers or conductors. In the preferred embodiment, the microstructure of the present invention includes a shelf feature disposed along a height dimension of the microstructure, which is required for some applications.The bulk micromachining method of the present invention includes providing a first substrate having a top planar surface and an opposing planar surface. The opposing surface of the substrate is anisotropically etched to provide a first thinned region. The top surface of the first substrate is anisotropically etched so that a first recessed feature having a vertical side is made integral with the first thinned region.

Abstract: A two stage non-imaging optical concentrator providing high concentration while providing a low aspect ratio and a wide field of view. The invention includes a non-imaging refractive member and a non-imaging reflective funnel member. The reflective funnel has a broad extremity and an opposing narrow extremity. The refractive member is disposed substantially within the funnel, proximate to the narrow extremity of the funnel, so as to provide a low aspect ratio of the two stage non-imaging concentrator of the invention. The low aspect ratio of the concentrator of the invention advantageously provides for compact and efficient packaging of the concentrator in conjunction with mobile optical communication link components.

Abstract: A simplified semaphore method and apparatus for simultaneous execution of multiple semaphore instructions and for enforcement of necessary ordering. A central processing unit having an instruction pipeline is coupled with a data cache arrangement including a semaphore buffer, a data cache, and the semaphore execution unit. An initial semaphore instruction having one or more operands and a semaphore address are transmitted from the instruction pipeline to the semaphore buffer, which in turn are transmitted from the semaphore buffer to the semaphore execution unit. The semaphore address of the initial semaphore instruction is transmitted from the instruction pipeline to the data cache to retrieve initial semaphore data stored within the data cache at a location in a data line of the data cache as identified by the semaphore address.

Abstract: An apparatus including a cache subsystem arrangement for efficient management of input/output operations and of memory shared by processors in a multiprocessor system. The apparatus includes a central processing unit, an input/output device such as a network device or a display device for example, and the cache arrangement, which includes a coalescing buffer coupled with the data processing unit for receiving non-cacheable data from the processing unit. The non-cacheable data is combined in the coalescing buffer into non-cacheable data blocks. A system bus is coupled with the buffer and the input/output device for storing the non-cacheable data blocks to the input/output device. By combining the non-cacheable data before storage to the input/output device, the coalescing buffer provides higher performance in the multiprocessor system, since fewer bus transactions are issued for serial store operations and more stores can complete in a given amount of time than if they were issued singly on the bus.

Abstract: A method and apparatus for snooping both cache memory and associated buffer queues in a cache subsystem arrangement. Since there are usually several requests for cache data being handled at any given time under high performance operation of multiple processors, a cache arrangement includes at least one buffer queue for storing the address of the cache data line and the status of the cache data line, which facilitate keeping track of the data requests and handling them efficiently. In response to a snoop request, a snoop address is compared to the address stored in the buffer queue so as to provide a positive comparison result if the snoop address matches the address stored in the buffer queue, thereby indicating a snoop hit condition. The buffer queue of the cache arrangement further has a snoop hit bit for storing a record of the positive comparison result that indicates the snoop hit condition.

Abstract: An apparatus for providing efficient transmission of a beam of acoustic wave between an ultrasonic transducer and a remotely located body under examination by the beam. The apparatus includes a housing having an interior arranged so that the ultrasonic transducer is disposed therein. A prism is acoustically coupled with the transducer and with an acoustic waveguide having a longitudinal dimension extending outwardly from the interior of the housing. The acoustic prism is fixedly coupled with a proximate portion of the waveguide so as to provide efficient transmission of the beam of acoustic waves between the prism and the waveguide. Accordingly, The beam of acoustic waves is transmitted from the transducer, through the prism, and along the longitudinal dimension of the waveguide, to a distal portion of the waveguide. The distal portion of the waveguide is inserted into a remotely located patient's body under examination.

Abstract: A method and apparatus for three dimensional ultrasonic scanning with reduced electronic switching and cabling requirements. The invention includes a body including a relaxor ferroelectric ceramic material and electrodes coupled to opposing surfaces of the body. Electronic switches select electrodes so as to select column regions of the body that are arranged adjacent to one another in a row extending radially outward from a central axis of the body. A bias voltage source is coupled with the electronic switches for substantially polarizing ceramic material within the selected column regions of the body. A sector controller dynamically configures the electronic switches to rotationally vary a position of the row arrangement of selected column regions. An oscillating voltage source excites the row of selected column regions to emit an acoustic beam, so that the beam rotationally scans the medium as the sector controller rotationally varies the position of the row arrangement.