摘要:
Techniques for matching the speed of a microprocessor to potentially slower external system components. A master clock signal is communicated to a clock generator on the processor chip. The clock generator provides at least one external clock signal, which is communicated to various portions of the system. The clock generator includes programmable clock division circuitry that allows the external clock signal to be generated at any selected one of a plurality of fractions of the master clock frequency. The data pattern (the particular cycles in a sequence during which the processor outputs a data word as part of a multiple-data-word sequence) is programmable independently of the external clock programming.
摘要:
Techniques for matching the speed of a microprocessor to potentially slower external system components. A master clock signal is communicated to a clock generator on the processor chip. The clock generator provides at least one external clock signal, which is communicated to various portions of the system. The clock generator includes programmable clock division circuitry that allows the external clock signal to be generated at any selected one of a plurality of fractions of the master clock frequency. The data pattern (the particular cycles in a sequence during which the processor outputs a data word as part of a multiple-data-word sequence) is programmable independently of the external clock programming.
摘要:
Techniques for providing a number of precisely synchronized clock signals at a number of different frequencies at each of a plurality of locations on a chip. A number of synchronized clock signals are generated at an initial location on the chip, and distributed to the various locations with relative delay times that are equal to within a precision, which may be less than the ultimate precision required. A single synchronization signal is also generated at the initial location, and is distributed to the remote locations with delay times that are equal to each other to a precision that corresponds to the precision required of all the clock signals. Separate synchronization circuitry at each remote location receives the clock signals and the synchronization signal, and resynchronizes the clock signals to the precision with which the synchronization signal was distributed. The set of lines is configured as a tree structure. The clock generation system has a cycle-down mode wherein all the clock frequencies are divided by a desired divisor. The frequency division occurs in response to a cycle-down signal, but the different clock frequencies are not switched until all have their rising edges aligned. The result is that the state of the machine is preserved when the clocks are cycled down.
摘要:
A processor controlled interface between a processor, instruction cache, and main memory provides for simultaneously refilling the cache with an instruction block from main memory and processing the instructions in the block while they are being written to the cache.
摘要:
An apparatus, method, and system are disclosed for providing AC line power to lighting devices such as light emitting diodes (“LEDs”). A representative apparatus comprises: a plurality of LEDs coupled in series to form a first plurality of segments of LEDs; a plurality of switches coupled to the plurality of segments of LEDs to switch a selected segment into or out of a series LED current path in response to a control signal; a current sensor; and a controller which, in response to a first parameter and during a first part of an AC voltage interval, generates a first control signal to switch a corresponding segment of LEDs into the series LED current path; and during a second part of the AC voltage interval, generates a second control signal to switch the corresponding segment of LEDs out of the first series LED current path.
摘要:
A method and apparatus for restarting an instruction processing pipeline after servicing one or more interlock processing faults. A pipeline architecture is defined in which processing interdependencies (such as instruction latencies, resource conflicts, cache accesses, virtual address translations and sign extend operations) are presumed not to be present so as to increase pipeline throughput. Interdependencies which actually occur appear as processing faults which then are serviced. At the completion of the servicing, pipeline restarting operations occur, during which the portions of the pipeline which are invalidated are preloaded. Preloading includes backing-up the invalidated stages and re-executing such stages with corrected information so as to fill the pipeline. The pipeline portions (e.g., stages) which are invalidated are determined by the type of processing fault which occurs. Upon completion of preloading, normal instruction pipeline processing resumes.
摘要:
A structure and a method are provided in a table lookaside buffer (TLB) for translating a virtual memory address to a physical memory address. The virtual memory address is computed by adding to a base address an offset value. In the TLB of the present invention, each entry of the TLB is stored a previous base address, a partial sum of the previous virtual memory address computation, the sign bit of the previous offset value, and the value of the carry bit at the position of the sign bit of the previous offset value in the previous virtual memory address computation. The present invention is especially applicable to a data TLB used in conjunction with a two-way set associative data cache memory.
摘要:
A CPU or other function unit is disclosed which follows one data ordering scheme internally, and in which incoming and/or outgoing data pass through a data order conversion unit for adapting it to a selectable external data ordering scheme. The means for specifying the external data ordering scheme is accessible from outside the physical package(s) in which the functional unit is housed. The data order conversion unit may comprise a load aligner and/or a store aligner, one or both of which may comprise means for shifting informational units of a smaller size within informational units of a larger size. The shift amount may derive from the low order address bits and may be altered depending on the external data ordering means selected.
摘要:
An apparatus, method, and system are disclosed for providing AC line power to lighting devices such as light emitting diodes (“LEDs”). A representative apparatus comprises: a plurality of LEDs coupled in series to form a first plurality of segments of LEDs coupled in series; a plurality of switches coupled to the plurality of segments of LEDs to switch a selected segment into or out of a series LED current path in response to a control signal; a memory; and a controller which, in response to a first parameter and during a first part of an AC voltage interval, determines and stores in the memory a value of a second parameter and generates a first control signal to switch a corresponding segment of LEDs into the series LED current path, and during a second part of the AC voltage interval, when a current value of the second parameter is substantially equal to the stored value, generates a second control signal to switch a corresponding segment of LEDs out of the first series LED current path.
摘要:
An apparatus, method and system are disclosed for providing AC line power to lighting devices such as light emitting diodes (“LEDs”). An exemplary apparatus comprises: a plurality of LEDs coupled in series to form a first plurality of segments of LEDs; a plurality of switches coupled to the plurality of segments of LEDs to switch a selected segment into or out of a series LED current path in response to a control signal; a current sensor; and a controller which, in response to a first parameter and during a first part of an AC voltage interval, generates a first control signal to switch a corresponding segment of LEDs into the series LED current path; and during a second part of the AC voltage interval, generates a second control signal to switch a corresponding segment of LEDs out of the first series LED current path.