Abstract:
A digital FM demodulator and method for determining phase changes in highly oversampled complex FM digital signals is described. In a first embodiment the FM signal is oversampled with respect to the frequency of its associated modulating signal. In this embodiment a first digital processing stage delays and conjugates the original FM signal. This delayed conjugated original FM signal is then multiplied with the original FM signal to generate a second signal that represents the changes in the phase between samples of the original FM signal. A second processing stage then delays and conjugates the second signal. The delayed conjugated second signal is then multiplied with the original second signal to generate a third signal that represents changes in the phase between samples of the second signal. The imaginary component of the third signal is passed through a digital integrator which outputs the phase changes of the original FM signal. In a second embodiment, the highly oversampled signal is oversampled with respect to the deviation frequency of its associated modulating signal. In this embodiment the center frequency of the original FM signal is frequency shifted to approximately zero frequency. This frequency shifted signal is then delayed and conjugated. The delayed conjugated shifted signal is then multiplied with the original frequency shifted signal; yielding an output signal where the imaginary portion of the output signal is equal to the phase changes of the original FM signal.
Abstract:
The present invention is an improvement of a digital topology including a logic block portion and a buffer portion. The improved buffer portion of the present invention is implemented with first and second parallel, same conductivity type transmission gates. The transmission gates couple either a first (V1) or second (V2) voltage onto the output of the buffer (55) in response to a logic signal originating from the logic block portion. The first (V1) and second (V2) voltages are selected to be relatively close in magnitude such that the peak-to-peak voltage of the digital output signal seen on the output of the buffer is relatively small. As a result, power consumption for charging the output of the buffer is minimized. In addition, the parallel transmission gates only consume power while charging the output of the buffer so that quiescent power consumption of the buffer is eliminated. Quiescent power dissipation is also eliminated in certain types of logic block designs that include logic gates having constant current sources. This is achieved by enabling the current sources with a pulse signal. The pulse width and magnitude of the pulse signal is selected to allow a latched sense amplifier to sense valid data from the output of the logic block portion during a specified interval. After valid data is sensed, the logic blocks's current sources are disabled, and the logic block portion no longer consumes any power. The sense amplifier is enabled for intervals long enough to capture the data from the logic block and drive the transmission gates with the data. In this configuration, none of the elements in the topology dissipate quiescent power since none of them are constantly operating.
Abstract:
An improvement for reducing proximity effects comprised of additional lines, referred to as intensity leveling bars, into the mask pattern. The leveling bars perform the function of adjusting the edge intensity gradients of isolated edges in the mask pattern, to match the edge intensity gradients of densely packed edges. Leveling bars are placed parallel to isolated edges such that intensity gradient leveling occurs on all isolated edges of the mask pattern. In addition, the leveling bars are designed to have a width significantly less than the resolution of the exposure tool. Therefore, leveling bars that are present in the mask pattern produce resist patterns that completely developed away when a nominal exposure energy is utilized during exposure of photoresist.
Abstract:
A programmable processor and method for improving the performance of processors by expanding at least two source operands, or a source and a result operand, to a width greater than the width of either the general purpose register or the data path width. The present invention provides operands which are substantially larger than the data path width of the processor by using the contents of a general purpose register to specify a memory address at which a plurality of data path widths of data can be read or written, as well as the size and shape of the operand. In addition, several instructions and apparatus for implementing these instructions are described which obtain performance advantages if the operands are not limited to the width and accessible number of general purpose registers.
Abstract:
A system for processing geometry which reduces the amount of memory spaces while improving the processing speed. The system delivers vertices in sequence to a vertex queue (70) so that data in the vertex queue is freed as it is delivered and only minimal intermediate results are stored. By this incremental evaluation, less memory space is needed. In another aspect of the invention the vertices are maintained in the proper sequence so that sorting operation can be eliminated. A sorted vertex queue (70) and an unsorted vertex list (72) are utilized so that resorting of the entire vertex list may be prevented. In addition, a compressed format (34) for storing geometry is utilized based on the fact that much information can be rederived from a sorted and reduced vertex queue.
Abstract:
A compact FIR filter uses one or both of a compact address sequencer and a compact multiplier/accumulator. The address sequencer exploits certain symmetry properties existing between different phases of a polyphase FIR filter in order to reduce coefficient storage and simplify address sequencing. The multiplier/accumulator is capable of performing two multiply/accumulate operations per clock cycle, avoiding in certain instances the need to add a second multiplier/accumulator. The area required to realize an FIR filter for performing real-time filter is therefore reduced.
Abstract:
A direct digital synthesizer (DDS) for generating a waveform generates a sequence of n-bit phase signals representing phase of the waveform, wherein n is an integer greater than zero. Each n-bit phase signal comprises a phase estimate signal and a phase error signal. The phase estimate signal comprises a most-significant m bits of the n-bit quantity (0
Abstract:
A two-stage flash analog-to-digital signal converter is described. The first stage has a voltage divider network and a set of amplifiers that perform an initial interpolation. The initial interpolation results are directly coupled, i.e., no resistive or capacitive elements, to a second stage comprising a set of comparators having multiple inputs. The multiple inputs of the second stage comparators are weightily coupled to the first stage amplifiers in a manner so as to cause the second stage comparators to generate a digital representation of the analog signal.
Abstract:
A method of printing a sub-resolution device feature (16) having first and second edges spaced in close proximity to one another on a semiconductor substrate (20) includes the steps of first depositing a radiation-sensitive material on the substrate, then providing a first mask image segment (11) which corresponds to the first edge. The first mask image segment is then exposed with radiation (10) using an imaging tool (12) to produce a first pattern edge gradient (14). The first pattern edge gradient defines the first edge of the feature in the material. A second mask image segment (13) is then provided corresponding to the second feature edge. This second mask image segment is exposed to radiation (10) to produce a second pattern edge gradient (17) which defines the second edge of the feature. Once the radiation-sensitive material has been developed, the two-dimensional feature is reproduced on the substrate.
Abstract:
A bipolar transistor having an emitter (25), a base (31), and a collector (30) includes an intrinsic base (33) region having narrow side areas (p-) and a wider central area (37). The side areas are located adjacent to the extrinsic base region (31), while the central area (37) is disposed underneath the emitter (25). The lateral doping profile of the base is tailored so that the doping concentrations in the extrinsic region (31) and the central area (37) are relatively high compared to the doping concentration of the narrow side areas (p-) of the intrinsic base (33). The combination of the narrow side areas (p-) and the lateral base doping profile constrains the depletion region within the base thereby lowering punch-through voltage of the transistor without loss of beta.