Abstract:
A method, algorithm, circuits, and/or systems for amplitude shift keying (ASK) modulation are disclosed. In one embodiment, a sampling demodulator includes a comparator configured to compare an ASK modulated input to a predetermined voltage level and provide a comparison result, a pulse stretcher with a sampler configured to sample the comparison result a plurality of times for each of a plurality of cycles of the ASK modulated input to generate a bit stream and digital logic configured to determine a value for each data bit in the ASK modulated input from the bit stream, and a digital filter configured to filter an output of the digital logic, thereby providing a demodulated signal.
Abstract:
Apparatuses and methods for receiving an amplitude modulated signal in one of two modes depending on the quality of the received signal. In a first mode, the amplitude modulated signal is converted directly to a baseband signal. In a second mode, the amplitude modulated signal is converted to an intermediate frequency signal. The present invention advantageously combines direct conversion and image-rejection heterodyne receiver topologies with a relatively large degree of component reuse and relatively few additional components.
Abstract:
Circuits and methods and for generating oscillator outputs using standard integrated circuit components. The basic circuit generally includes two inverters and a variable capacitor to configure a delay of the circuit input and/or output. The oscillator circuit generally includes a plurality of inverter circuits, at least one of which uses a variable capacitor to adjust a delay between stages, and thereby adjust a frequency of oscillation. Thus, the oscillator outputs may be tuned using a single control voltage. The method generally includes the steps of (1) applying an operating voltage to a ring oscillator comprising a plurality of stages; and (2) applying a control voltage to a variable capacitor coupled to a node between at least two of those stages. The circuits have particular advantage in quadrature oscillators, and may be easily implemented using widely available CMOS technology.
Abstract:
A method for maintaining signal integrity of a differential output signal generated from a differential driver is disclosed. The method includes receiving the differential output signal from the differential driver. Once received, the method includes tuning the differential output signal by exposing the differential output signal to an inductance. The inductance is configured to reduce signal mismatch between complementary signals of the differential output signal. The signal mismatch is a result of having each of the complementary signals exposed to different capacitive loading. A device and system is also provided, which include integrating an inductor between the output leads of a differential driver. The inductor is sized for the particular frequency of operation, and the inductor provides an inductance that assists in eliminating mismatch between the complementary signals of the differential output. A reduction and/or elimination of the mismatch will assist in improving the rise-time of the differential signals.
Abstract:
An improved integrated LC resonator and methods for making and using the same are disclosed. The resonator includes (i) a first capacitor plate; (ii) an inductor over and in electrical communication with the first capacitor plate; and (iii) a second capacitor plate over and in electrical communication with the inductor. The method of making includes sequentially forming a first capacitor plate, a first dielectric layer thereon, a first via and an inductor, a second dielectric layer on the inductor, and a second via and a second capacitor plate. Each of the capacitor plates and the inductor are generally formed in different integrated circuit layers (for example, different metallization layers). Embodiments of the present invention can advantageously provide an integrated LC resonator tank having: (i) relatively high Q by reducing or minimizing parasitic effects; and (ii) relatively high shielding from the semiconductor substrate.
Abstract:
A CML master-slave latch incorporates logic into its master latching circuitry to incorporate a multiplexing function into the flip-flop. The multiplexing logic makes use of the pull-up loads and current source of the master latching circuitry. In this manner the pull-up loads and current source typically required for a stand-alone multiplexor are eliminated. Subsequently, the size of the present hybrid master-slave latch is smaller and consumes less power than a traditional combination of an independent multiplexor and master-slave latch. Since the master latching circuitry feeds only into the slave latching circuitry, the pull-up loads and the current sources of the master latching circuitry and slave latching circuitry may be optimized separately for achieving faster performance or less power consumption.
Abstract:
A structure and method for implementing a fully digital frequency difference detector uses an n-bit counter to count cycles of a reference clock signal and an m-bit counter to count cycles of a synthesized clock signal, where m is greater than n. The two counters operate concurrently, and both are halted when the n-bit counter overflows into its nth bit position. Two latches respectively record if bits n and (n+1) in the m-bit become set prior to the n-bit counter overflowing. By observing the state of the two latches and the state of a predefined bit range within the m-counter, the frequency difference detector can determined if the frequency of the synthesized clock is greater than, less than, or locked to the frequency of the reference clock signal.
Abstract:
A fully differential phase and frequency detector utilizes a multi-function differential logic gate to implement a differential AND gate operation and provides a fully differential D-flip-flop. The multi-function differential logic gate has four inputs, which can be grouped into two pairs of true and complement signals. By selectively re-assigning the inputs to different signal pairs, the differential logic gate can be made to provide one of either simultaneous AND/NAND logic operations or simultaneous OR/NOR logic operations. The differential D-flip-flop is implemented following a master/slave configuration and is response to the true and complement forms of an input clock signal, an input reset input, and input data signal, and also provides true and complement forms of an output signal. All components within the phase and frequency detector are exemplified in CML circuit configuration.
Abstract:
An instruction fetching system (and/or architecture) which may be utilized by a high-frequency short-pipeline microprocessor, for efficient fetching of both in-line and target instructions. The system contains an instruction fetching unit (IFU), having a control logic and associated components for controlling a specially designed instruction cache (I-cache). The I-cache is a sum-address cache, i.e., it receives two address inputs, which compiled by a decoder to provide the address of the line of instructions desired fetch. The I-cache is designed with an array of cache lines that can contain 32 instructions, and three buffers that each have a capacity of 32 instructions. The three buffers include a Predicted (PRED) buffer that holds the instructions which are currently being executed, a NEXT buffer that holds the instructions which are to be executed after the instructions in the PRED buffer, and an ALT buffer that holds the alternate set of instructions when a branch is predicted taken/not taken and is utilized along with the PRED buffer to permit branch target retrieval within I-cache prior to a prediction.
Abstract:
The present invention relates to multiprocessors which has several microprocessors on a single chip. Efficiency is improved by stripping certain functions that are used less freely from the microprocessor and sharing these functions between several symmetric microprocessors. This method allows each CPU to occupy a smaller area while preserving complete symmetry of capability for software simplification. For example, the shared execution units can include the floating point unit and multimedia execution units.