Class / Patent application number | Description | Number of patent applications / Date published |
327150000 | With digital element | 6 |
20090256600 | INPUT CLOCK DETECTION CIRCUIT FOR POWERING DOWN A PLL-BASED SYSTEM - An apparatus is provided for detecting the loss of an input clock signal for a phase-locked loop (PLL). The apparatus includes a time delay circuit, a first frequency divider and a digital logic circuit. The time delay circuit receives the input clock signal and outputs a first time-delayed clock signal. The first frequency divider receives an input signal from an internal clock of the PLL and outputs a clock signal having the same frequency or a lower frequency than that of the time-delayed clock signal. The digital logic circuit that receives the first frequency divider output signal and the first time-delayed clock signal and outputs a signal indicating the loss of the input clock signal if there is no first time-delayed clock signal for a cycle of the first frequency divider output signal. | 10-15-2009 |
20130043917 | HARDWARE CONTROLLED PLL SWITCHING - A system and method for efficiently managing multiple PLLs on a system on a chip (SOC). A SOC includes a hardware phase lock loop (PLL) switching control block coupled to a software interface. The hardware PLL switching (HPS) control block receives PLL switch requests from software. The request identifies a given core clock received by a given processing core of multiple processor cores on the SOC and indicates the identified core clock is not to be provided anymore by a current PLL. The request indicates a given search method including search conditions. The HPS control block searches for a target PLL that satisfies these search conditions. In response to finding the target PLL, the HPS control block changes clock network connections and parameters across the die of the SOC. These changes across the die disconnect the identified core clock from the current PLL and connects the identified core clock to the target PLL. | 02-21-2013 |
20130181754 | HIGH JITTER AND FREQUENCY DRIFT TOLERANT CLOCK DATA RECOVERY - In a method for recovery of a dock from a received digital data stream and an apparatus for recovering a clock from a received digital data stream, phase-shifted dock signals are generated from a receiver's dock. After selecting one of the phase-shifted clock signals, two other phase-shifted clock signals are determined. Depending on sample values taken at rising/falling edges of the three selected phase-shifted clock signals, counter values are increased and compared. The selection of phase-shifted clock signals and the steps of sampling the input digital data stream, comparing the values and increasing counter values, if required, are repeatedly performed until the comparison result of the counter values indicates that one of the latter determined phase-shifted clock signals strobes the received digital data stream in the centre of a bit period. | 07-18-2013 |
20130200931 | CIRCUIT DEVICE, FREQUENCY CHANGING CIRCUIT, METHOD OF TESTING CIRCUIT DEVICE, AND METHOD OF CONTROLLING FREQUENCY CHANGING CIRCUIT - A circuit device includes a clock generator outputting a clock signal having a first frequency; plural phase controllers inputting the clock signal having the first frequency, and outputting clock signals having the first frequency and having phases advanced or delayed with respect to a phase of the clock signal; a selector inputting the plural clock signals having the first frequency output from the plural phase controllers, sequentially selecting pulses of the plural clock signals, and outputting a clock signal having a second frequency; a pattern generator generating a test pattern based on the clock signal having the second frequency; and a circuit inputting the clock signal having the second frequency and the test pattern generated by the pattern generator, operate based on the clock signal having the second frequency, and outputting operation results. | 08-08-2013 |
20140210525 | Hitless Switching Phase-Locked Loop - A PLL includes an oscillator, multiple time-to-digital converters (TDCs) and a system for the remaining functionality. The TDCs measure the oscillator's phase against respective multiple reference clocks. The system compares the respective measured phases with respective desired phases to obtain phase error signals. One is selected to close the loop. The others are monitored and adjusted when not equal to zero. When a new reference clock must be used, the loop is changed from including the old phase error signal to the new. The old phase error was zero because the loop was in lock, the new phase error is zero because it was monitored and adjusted. Therefore, upon switching the loop from the old to the new phase error signal, the loop remains locked and switching is hitless. | 07-31-2014 |
20140266337 | NOISE MANAGEMENT METHOD AND CIRCUIT FOR ASYNCHRONOUS SIGNALS - Noise may be reduced by delaying signal propagation outside of a time window when a change in another signal is expected. A time window may be defined between the change of the first clock signal and the change of the second clock signal during which a third signal, such as a data signal, does not propagate through the circuit. When a change occurs in a third signal after the first clock signal change while the first clock signal is at a different level than a second clock signal, propagation of the third signal change may be delayed until a change in the second clock signal is received. Delayed propagation may be achieved through a latch and hold circuit with no metastability. | 09-18-2014 |