A clock divider includes, in part, a pair of counters and a programmable delay line. A first one of the counters operates at a first frequency and is configured to count using a first integer portion of the divisor. The second counter operates at a second frequency smaller than the first frequency and is configured to count using a second integer portion of the divisor. The programmable delay line includes, in part, a chain of delay elements configured to generate a multitude of delays of the output of the second counter. A multiplexer selects one of the generated delays in accordance with the fractional portion of the divisor. The second counter increases its count only when the first counter reaches a terminal count. The first and second integer portions are loaded respectively into the first and second counters when the second counter reaches its terminal count.

The invention relates to a frequency multiplying device for determination of a fundamental frequency f of an analogue target signal. The device comprises a generating device for generating a reference signal having a frequency f.sub.osc, wherein f.sub.osc is greater than f, and a first counter being coupled to a terminal, the terminal to be fed with the analogue target signal, and being coupled to the generating device such that the first counter counts a number of signal edges generated from the reference signal in a time interval corresponding substantially to 1/f and outputs a first counter signal, wherein a frequency divider is coupled between the generating device and the first counter and a second counter is coupled to the generating device for counting signal edges of a signal generated from the reference signal the second counter outputting a second counter signal and a comparator is coupled to the first counter to receive the first counter signal and coupled to the second counter to receive the second counter signal, wherein the comparator generates a signal in the event the first counter signal is equal to the second counter signal, and the output of the comparator is coupled to reset the second counter.

The invention relates to a frequency multiplying device for determination of a fundamental frequency f of an analogue target signal. The device comprises a generating device for generating a reference signal having a frequency f.sub.osc, wherein f.sub.osc is greater than f, and a first counter being coupled to a terminal, the terminal to be fed with the analogue target signal, and being coupled to the generating device such that the first counter counts a number of signal edges generated from the reference signal in a time interval corresponding substantially to 1/f and outputs a first counter signal, wherein a frequency divider is coupled between the generating device and the first counter and a second counter is coupled to the generating device for counting signal edges of a signal generated from the reference signal the second counter outputting a second counter signal and a comparator is coupled to the first counter to receive the first counter signal and coupled to the second counter to receive the second counter signal, wherein the comparator generates a signal in the event the first counter signal is equal to the second counter signal, and the output of the comparator is coupled to reset the second counter.

A memory device includes a clock generating circuit suitable for generating a plurality of internal clock signals based on an external clock signal during an output period of read data, in response to a read command, and a data strobe output circuit suitable for outputting a first data strobe signal to a data strobe pad in response to the internal clock signals, wherein the internal clock signals toggle regardless of the output period of the read data, in response to a test mode signal.

A memory device includes a clock generating circuit suitable for generating a plurality of internal clock signals based on an external clock signal during an output period of read data, in response to a read command, and a data strobe output circuit suitable for outputting a first data strobe signal to a data strobe pad in response to the internal clock signals, wherein the internal clock signals toggle regardless of the output period of the read data, in response to a test mode signal.

A circuit for transferring a n-bit phase value between circuits includes a system clock input, a n-bit phase value generator coupled to the system clock input generating a phase value output, and an edge output indicating the phase output value is valid, a latching clock delay circuit having an input coupled to the system clock input, an input coupled to the edge output, a variable phase delay circuit coupled to the phase value output, a delay adder having a first input coupled to the phase value output, a second input coupled to a delay offset signal, and an output coupled to the control input of the variable phase delay circuit, and a phase flip-flop having a data input coupled to the output of the variable phase delay circuit, a clock input coupled to a latching clock output of the variable output clock delay circuit and a Phase Out output.

A memory device includes a clock generating circuit suitable for generating a plurality of internal clock signals based on an external clock signal during an output period of read data, in response to a read command, and a data strobe output circuit suitable for outputting a first data strobe signal to a data strobe pad in response to the internal clock signals, wherein the internal clock signals toggle regardless of the output period of the read data, in response to a test mode signal.

A memory device includes a clock generating circuit suitable for generating a plurality of internal clock signals based on an external clock signal during an output period of read data, in response to a read command, and a data strobe output circuit suitable for outputting a first data strobe signal to a data strobe pad in response to the internal clock signals, wherein the internal clock signals toggle regardless of the output period of the read data, in response to a test mode signal.

An illustrative PLL circuit and method for generating a clock signal over a wide frequency range without gaps. In one illustrative embodiment, an extended-range PLL includes: a phase comparator that determines a phase error between a reference clock and a feedback clock; a loop filter that converts the phase error into a control signal; a voltage controlled oscillator (VCO) that provides a generated clock signal having a generated clock frequency determined by the control signal; a divide-by-1.5 block that produces a reduced-frequency clock signal in response to the generated clock signal; and a multiplexer that selects one of the generated clock signal and the reduced-frequency clock signal as a selected clock signal.

A multi-modulus frequency divider circuit includes first and second frequency division stages. The first frequency division stage receives a first input clock signal having a first oscillating frequency, a first modulus input signal, and a first division bit. The first frequency division stage divides the first oscillating frequency by a first division ratio, and generates a second input clock signal having a second oscillating frequency. The second frequency division stage receives the second input clock signal, a second modulus input signal, and a second division bit. The second frequency division stage generates an output clock signal having an output oscillating frequency by dividing the second oscillating frequency by a second division ratio.