Abstract: The present invention provides for a circuit for transitioning clocking speeds. A counter is coupled to the clocking means. A comparator is coupled to an output of the counter. A first divider is coupled to the output of the counter. A processor means is coupled to the output of the first divider, thereby lessening current surges.

Abstract: A voltage calibration system includes three main units, which are a voltage level trimming unit, a trim detection unit, and a trim control unit. The three units work in conjunction with each other during a trimming operation in order to identify a tap voltage that is closest to a target voltage. In one embodiment, the voltage calibration system may be used to calibrate a voltage regulator. Upon commencement of calibration, the voltage regulator's feedback loop is open, and the target voltage is selected as the input for the feedback port of the amplifier. The voltage regulator serves as a voltage comparator that compares each tap voltage to the target voltage. When the calibration is complete, regulator's feedback loop is closed and the closest tap voltage to the target voltage is used as the regulator's input.

Abstract: In one embodiment, the disclosed methodology and apparatus measure relative duty cycle information of a clock signal with respect to an input node as the clock signal travels to selected nodes of a clock distribution network on an electronic circuit. The apparatus operates in a benchmark mode to determine benchmark duty cycle information and then subsequently operates an a relative mode to determine relative duty cycle information of the clock signal at a selected node in comparison to the clock signal at an external input node.

Abstract: A system and system for automatic voltage calibration is presented. A voltage calibration system includes three main units, which are a voltage level trimming unit, a trim detection unit, and a trim control unit. The three units work in conjunction with each other during a trimming operation in order to identify a tap voltage that is closest to a target voltage. In one embodiment, the voltage calibration system may be used to calibrate a voltage regulator. Upon commencement of calibration, the voltage regulator's feedback loop is open, and the target voltage is selected as the input for the feedback port of the amplifier. The voltage regulator serves as a voltage comparator that compares each tap voltage to the target voltage. When the calibration is complete, regulator's feedback loop is closed and the closest tap voltage to the target voltage is used as the regulator's input.

Abstract: A method, an apparatus, and a computer program are provided to measure and/or correct duty cycles. Duty cycles of various signals, specifically clocking signals, are important. However, measurement of very high frequency signals, off-chip, and in a laboratory environment can be very difficult and present numerous problems. To combat problems associated with making off-chip measurements and adjustments of signal duty cycles, comparisons are made between input signals and divided input signals that allow for easy measurement and adjustment of on-chip signals, including clocking signals.

Abstract: The present invention provides for a circuit for transitioning clocking speeds. A counter is coupled to the clocking means. A comparator is coupled to an output of the counter. A first divider is coupled to the output of the counter. A processor means is coupled to the output of the first divider, thereby lessening current surges.

Abstract: The disclosed methodology and apparatus measures the duty cycle of a clock signal. A variable duty cycle circuit receives a clock signal from a clock signal generator. The variable duty cycle circuit adjusts the duty cycle of the clock signal by an amount dependent on a duty cycle index value that it receives. The variable duty cycle circuit supplies a duty-cycle adjusted clock signal to a divider circuit. The apparatus sweeps the frequency of the clock signal from a starting value up to a maximum frequency above which the divider circuit fails. The apparatus then determines the duty cycle of the duty-cycle adjusted clock signal from the maximum frequency.

Abstract: The disclosed methodology and apparatus measure and correct the duty cycle of a reference clock signal that a clock circuit supplies to a duty cycle measurement (DCM) circuit. In one embodiment, the DCM circuit includes a capacitor driven by a charge pump. The reference clock signal drives the charge pump. The clock circuit varies the duty cycle of the reference clock signal among a number of known duty cycle values. The DCM circuit stores resultant capacitor voltage values corresponding to each of the known duty cycle values in a data store. The DCM circuit applies a test clock signal having an unknown duty cycle to the capacitor via the charge pump, thus charging the capacitor to a new voltage value that corresponds to the duty cycle of the test clock signal. Control software accesses the data store to determine the duty cycle to which the test clock signal corresponds, thus providing a measured duty cycle.

Abstract: A method and an apparatus are provided for limiting a pulse width in a chip clock design of a circuit. The circuit receives a clock signal having a clock pulse width. The clock pulse width of the clock signal is detected. It is determined whether the clock pulse width is larger than a maximum clock pulse width. Upon a determination that the clock pulse width is larger than a maximum clock pulse width, the clock pulse width of the clock signal is limited.

Abstract: A technology for supplying a power supply voltage to a microprocessor. Before normal arithmetic processing of the microprocessor, duty cycle correction process for adjusting the duty cycle of a clock signal inside the microprocessor is performed. In the duty cycle correction process for adjusting the duty cycle, the duty cycle of the clock signal is adjusted so as to minimize the power voltage at which the microprocessor is still operable.

Abstract: In one embodiment, the disclosed methodology and apparatus measure relative duty cycle information of a clock signal with respect to an input node as the clock signal travels to selected nodes of a clock distribution network on an electronic circuit.

Abstract: A method and apparatus is provided for testing the logic functionality and electrical continuity of a ring oscillator comprising an odd number of inverters connected to form a closed loop. In the method and apparatus, a known value is forced through the ring oscillator, to test the complete circuit path thereof. Thus, a low overhead deterministic test of the functionality of the ring oscillator is provided. In a useful embodiment of the invention, a method is provided for testing functionality and electrical continuity in a ring oscillator, wherein a first test device is inserted between the input of a first inverter and the output of an adjacent second inverter. The first test device is then operated to apply first and second test bits as input test signals to the first inverter input.

Abstract: The present invention provides for correcting excessive pulse widths using incremental delays. The pulse width is evaluated through a correction block and leak detector. An acceptable pulse passes through an interconnect directly to the clock output. Unacceptable pulses are sent through a block delay module that incorporates a series of delay sub-blocks that disconnect and reset in accordance with a pre-programmed total delay time. The conditioned clock pulse is resent through a node to the correction block and leak detector where it is reevaluated. If the pulse is acceptable, it is sent to the clock output. If the pulse is found unacceptable, it is recycled again. A high low clock pulse shuttle determines and alters the high or low state of the clock pulse to ensure a correct output to downstream dependent devices.

Abstract: A circuit topology which can be used to create an array of individually tuned oscillators operating at different frequencies determined by common control inputs and an easily managed variation in design dimensions of several components is provided. An array of oscillators are provided arranged in columns and rows. Each oscillator in a column is unique from the other oscillators in the column based on number of stages in the oscillator and fanout so that each oscillator will operate at a unique frequency. Oscillators of different columns within the array may differ by a common setting of the selects to these oscillators and the physical ordering of the oscillators in the column to further reduce the possibility of injection locking. A base delay cell provides selects to each column of oscillators such that each column may be programmed to operate at a different frequency from its neighbors.

Abstract: The present invention provides an integrated circuit. The integrated circuit has a plurality of chip areas. The integrated circuit also has a plurality of temperature sensors, at least one per chip area. The temperature sensors generate a voltage proportional to the measured temperature. A voltage comparator compares the voltage output of the plurality of temperature sensors. The voltage comparator is further employable to generate a signal if the difference between the voltages generated by the plurality of temperature sensors exceeds a threshold.

Abstract: The present invention provides for compensation of leakage charge in a PLL. A first plurality and second plurality of charge pumps has a source charge pump and a sink charge pump, and each charge pump has its own switch. A first node is coupled between at least one source charge pump and at least one sink charge pump. A second node coupled between at least one source charge pump and at least one sink charge pump. A PLL filter is coupled to the first node. A dummy filter is coupled to the second node. A first input of a differential mode sensor is coupled to the PLL filter. A second input of a differential mode sensor is coupled to the dummy filter. A first input of a common mode sensor is coupled to the dummy filter. A second input of a common mode sensor coupled to the PLL filter.

Abstract: The present invention provides a method, apparatus, and computer program for measuring the current leakage in a Low Pass Filter (LPF) capacitor of a Phased Locked Loop (PLL). As a result of thinner and thinner film capacitors in Complementary Metal-Oxide Semiconductor (CMOS) technology, leakage current, which causes a PLL to drift out of phase lock, has become an increasingly difficult problem. To overcome the leakage current problems, knowing the leakage current of an LPF capacitor is important to implement the correction circuitry. In the present invention, an external interface and a time interface analyzer are used to charge the LPF capacitor and measure the output frequency of the PLL's Voltage Controlled Oscillator. Because of the change in the output frequency, the leakage current can be determined.

Abstract: An improved charge pump used in a phase-locked loop includes transient current correction capability by adding a canceling capacitance for each parasitic capacitance associated with a switching device in a charge pump. For each transient current component flowing through the parasitic capacitance, a canceling capacitance is implemented to create a canceling transient current component in the opposite direction such that it cancels out the transient current component. Preferably, an additional switching device is added to implement such a canceling capacitance for each parasitic capacitance.

Abstract: A method, an apparatus, and a computer program are provided to minimize filter capacitor leakage in a Phased Locked Loop (PLL). In high frequency processors and devices, filter leakage currents can cause substantial problems by causing PLLs to drift out of phase lock. To combat the leakage currents, a dummy filter and other components are employed to provide additional charge or voltage to a low pass filter during lock. The provision of the charge or voltage exponentially decreases the rate of decay of voltage across the low pass filter caused by leakage currents.

Abstract: The present invention provides for state correction. A first value in a state circuit is received from a flip flop. The received value is transmitted to a second flip flop. The received value within the second flip flop is altered if an error condition arises. The received value is transmitted to a third flip flop. In one aspect, the received value transmitted to the third flip flop comprises an unaltered received value. In another aspect, the received value transmitted to the third flip flop comprises transmitting an altered received value. This allows for an incorrect state within the state machine to change to a correct state after a few clock pulses.