Abstract: An apparatus and a method for improving production yield of phase locked loops (PLLs) have been disclosed. One embodiment of the apparatus includes a PLL comprising a charge pump and an offset compensation circuit coupled to the charge pump to provide an offset current to the charge pump to reduce a static phase error of the PLL caused by a mismatch in at least one of a process variation, a voltage, and a temperature. Other embodiments are described and claimed.

Abstract: A method and an apparatus to bias a charge pump in a phase locked loop (PLL) to compensate a voltage controlled oscillator (VCO) gain have been disclosed. One embodiment of the apparatus includes a PLL comprising a charge pump, the charge pump comprising an input and an output, and a bias circuit coupled to the input of the charge pump, the bias circuit comprising a sensor circuit to sense a temperature and at least one of a voltage and a process variation and a current reference circuit coupled to the sensor circuit.

Abstract: An apparatus comprising a first circuit and a second circuit. The first circuit may be configured to present a parallel output data signal in response to (i) a first clock signal and (ii) one or more serial data signals. The second circuit may be configured to present the one or more serial data signals and the first clock signal in response to (i) a second clock signal and (ii) a parallel input data signal.

Abstract: An apparatus comprising a first circuit and a second circuit. The first circuit may be configured to generate a first select signal, a second select signal and a first data stream in response to an input data stream and a redundancy signal. The second circuit may be configured to generate an output data stream in response to the first data stream, the first select signal and the second select signal. The second circuit may be configured to replace one or more characters of the first data stream.

Abstract: An apparatus comprising an oscillator circuit and a logic circuit. The oscillator circuit may be configured to present an output signal having a frequency in response to (i) a reference signal, (ii) a control signal and (iii) the output signal. The logic circuit may be configured to present the control signal in response to (i) the output signal and (ii) the reference signal. In one example, the logic circuit may disable the oscillator when the output signal oscillates outside a predetermined range.

Abstract: An apparatus including a clock circuit and a control circuit. The clock circuit may be configured to generate a first output clock, a second output clock and a first control signal in response to (i) a first input clock, (ii) a second input clock, (iii) a second control signal and (iv) a third control signal. The control circuit may be configured to generate the second control signal and the third control signal in response to the first input clock and the first control signal. The first and second output clocks may have a skew less than a predetermined threshold.

Abstract: A circuit including a counter, a state machine and an update circuit. The counter may be configured to present a first control signal and a second control signal in response to a reset signal and a third control signal. The state machine may be configured to generate a select signal in response to (i) the reset signal, (ii) the first control signal and (iii) the second control signal. The update circuit may be configured to generate a fourth control signal in response to the select signal.

Abstract: An apparatus comprising an oscillator circuit and a logic circuit. The oscillator circuit may be configured to present an output signal having a frequency in response to (i) a reference signal, (ii) a control signal and (iii) the output signal. The logic circuit may be configured to present the control signal in response to (i) the output signal and (ii) the reference signal. In one example, the logic circuit may disable the oscillator when the output signal oscillates outside a predetermined range.

Abstract: An apparatus comprising a phase-locked loop, a select circuit and a control circuit. The phase-locked loop may be configured to generate a feedback signal (along with a buffered output signal) in response to a reference clock and a control signal. A select circuit may be configured to present a reference clock signal in response to a plurality of input clock signals and a select signal. The slew control circuit may be configured to generate the control signal in response to the select signal, and the feedback signal. The control circuit may be used to reduce noise presented to the phase-locked loop and may allow for a rapid initial frequency acquisition of the PLL to the reference frequency.

Abstract: An Asynchronous Transfer Mode ATM receiver is disclosed. The ATM receiver comprises an input that receives an ATM cell. A first-in first-out (FIFO) is coupled to the input. The FIFO stores the ATM cell received from the input. A header error correction (HEC) checking circuit is coupled to the input. The HEC checking circuit starts to check a header in the ATM cell for an error at substantially the same time when the ATM cell is being stored in the FIFO.

Abstract: A circuit comprising a plurality of phase locked loop circuits, a control circuit and a plurality of storage elements. Each of the plurality of phase locked loop circuits may present a recovered data signal and a recovered clock signal in response to one of a plurality of serial data streams, a clock signal and one of a plurality of indication signals. The control circuit may present a counter signal in response to the recovered clock signals. The plurality of storage elements may each be configured to present one of the indication signals in response to the clock signal, a select signal and the counter signal.

Abstract: A clock recovery phase locked loop system is described. One embodiment has a voltage controlled oscillator divider (the signal of which is compared with a REFCLK divider signal), a voltage stimulus input where a test voltage is applied, a time stimulus input where a digital input with appropriate pulse width is applied and a monitor (output) where the results of the measurement can be observed. A test system is included which applies a series of analog voltages to the voltage stimulus input. For each analog voltage, the test system apply a series of pulses to the time stimulus input. By monitoring (a) the level on the monitor output and (b) the time at which it switches, the VCO gain can be calculated. This allows a direct measurement of VCO gain (K.sub.v) using conventional automatic test equipment used to test digital logic or memory devices.

Abstract: A phase-lock loop circuit including a voltage-controlled oscillator for generating a clock signal. The voltage-controlled oscillator includes a plurality of multiplexers coupled in series. The signal generated by the last multiplexer in the series is used as a clock signal. Each of the multiplexers in the series has a select input. Either a first signal or a second signal propagates through the series of multiplexers, depending on a select signal applied to the select inputs of the multiplexers. The second signal is the first signal with a predetermined delay. A 3-input multiplexer is connected to the first and last multiplexers in the series to the form a ring oscillator. The first or second signals output by the last multiplexer in the series is sent to an input of the 3-input multiplexer, and a test signal is sent to a third input of the 3-input multiplexer. The 3-input multiplexer also receives the select signal and a test mode signal.

Abstract: An ECL circuit with power control is disclosed. The ECL circuit comprises a pair of emitter-coupled transistors with a current source transistor having its collector coupled to the coupled-emitters of the pair. Coupled in series with the base of the current source transistor is a first MOS transistor with its gate receiving an enable signal to control the first MOS transistor. As such, an activated first MOS transistor switches on the ECL circuit, and a de-activated first MOS transistor switches off the ECL circuit with no current through the current source transistor to provide a true power down of the ECL circuit. An ECL circuit for translating from CMOS to ECL levels is also disclosed. The ECL circuit comprises a pair of emitter-coupled transistors and first MOS transistor coupled in series with a first base of the pair at one end of the source/drain current path of the first MOS transistor.

Abstract: A system is disclosed which includes methods and apparatus for transmitting asynchronous nonhomogeneous variable width parallel data pattern inputs in a format suitable for use with a synchronous high speed serial link. The system further includes means for receiving the serially transmitted data which is capable of reversing the process performed by the transmitter, i.e. the receiver is capable of outputting the nonhomogeneous variable width parallel data as originally input to the system. The receiver is further operative to identify output data by type. The disclosed means for transmitting and means for receiving are each cascadable. As a result the disclosed system permits a wide variety of parallel data patterns to be manipulated, transmitted and received sharing a single serial interface.

Abstract: Apparatus and associated methods are disclosed for converting asynchronous nonhomogeneous variable width parallel data pattern signals to serial data pattern signals representative of said input signals and suitable for transmission over a synchronous high speed serial transmission media. The disclosed devices are modular, may each be packaged as a single semiconductor integrated circuit device, and may be cascaded. When cascaded, the devices permit parallel data pattern input signals generated by a plurality of data sources to be simultaneously converted to a single serial output bit stream suitable for high speed synchronous serial transmission.

Abstract: A system is disclosed which includes methods and apparatus for transmitting asynchronous nonhomogeneous variable width parallel data pattern inputs in a format suitable for use with a synchronous high speed serial link. The system further includes means for receiving the serially transmitted data which is capable of reversing the process performed by the transmitter, i.e. the receiver is capable of outputting the nonhomogeneous variable width parallel data as originally input to the system. The receiver is further operative to identify output data by type. The disclosed means for transmitting and means for receiving are each cascadable. As a result the disclosed system permits a wide variety of parallel data patterns to be manipulated, transmitted and received sharing a single serial interface.

Abstract: Apparatus is disclosed for introducing a precompensation delay in the path of a data signal to be written onto a magnetic medium, such as a floppy or hard disk. The apparatus includes a current controlled oscillator made up of delay elements having current control nodes, and means for controlling the current level being drawn from the current control nodes. The latter means includes three matched voltage controlled current sources having their outputs connected through a current splitter to the current control nodes, and bypass transistors for decoupling two of the voltage controlled current sources in response to a delay selection signal indicating whether the subject data pulse should be precompensated early, nominal or late.

Abstract: Methods are disclosed for operating receiver devices which take serial data patterns off a high speed synchronous serial transmission media and covert the data to parallel pattern outputs. According to the invention, each device operates under a "permission to capture" data protocol which allows a given receiver to operate at the byte rate of the transmitted data. Devices using the disclosed methods may be operated individually or in a cascaded fashion, In either mode, by enabling the receivers to transfer high speed data at the transmitted pattern byte rate, as opposed to the bit rate, the reliability and capacity of the receivers to field high speed data is enhanced. In addition, the disclosed methods obviate the need for receivers operating in a cascade mode to "know" their position in a cascade chain. As a result the operating simplicity and reliability of devices that employ the disclosed methods is further enhanced.

Abstract: Apparatus and associated methods are disclosed for converting serial data pattern signals, transmitted or suitable for transmission over a high speed synchronous serial transmission media, to parallel data pattern output signals. The disclosed devices are modular, may each be packaged as a single semiconductor integrated circuit device and are cascadable. When cascaded, the devices are capable of generating parallel data pattern output signals to one or more data sinks from a single serial bit stream.