122results about "Computations using pulse rate multipliers/dividers" patented technology

A frequency synthesis / multiplication circuit and method for multiplying the frequency of a reference signal. In one embodiment, multiple versions of the reference signal are generated having different phases relative to one another, and these multiple versions are combined to form an output signal having a frequency that is a multiple of the frequency of the reference signal.

A novel clock control circuit and method in which phase synchronization with respect to an external clock can be realized without recourse to the external clocks. A clock controlling circuit includes a delay circuit sequence comprised of N stages of units each made up of a first delay circuit 10 and a first interior division circuit 11 for delaying the output signal of the first delay circuit, and a phase difference detection circuit 14 for detecting the clock period and the delay time difference of the delay circuit sequence from the input clock IN and a clock END output by the delay circuit sequence as a phase difference of the two signals. A plural number of second interior division circuits 12, fed with an output signal of the first delay circuit, delays a transition edge of an output signal of the first delay circuit by t2-nxT / N to output the delayed signal. The second interior division circuit outputs a signal which makes transition at a timing delayed nxtCK / N as from the start time point of the clock cycle. A synthesis circuit 13 generates a frequency multiplied clock signal which is obtained on equal division of the clock period tCK of the input clock from the input clock IN and the number 1 to number N-1 third delays circuit.

The present invention provides a method and apparatus for synchronizing signal transfers between two clock domains, where the clock domains have a gear ratio relationship. A gear ratio means that the clocks are related by a ratio, such that each clock has a different integer number of clock cycles in a common period. Also, in addition to a gear ratio relationship, the clocks may have a synchronized edge at the end of the common period. For each clock, the cycles in the common period are “colored”, i.e., identified by a number (1st, 2nd, etc.). By using the coloring technique, the appropriate clock edge to perform a data or control signal transfer can be identified. The edges are preferably chosen to minimize the latency of the transfer.

The semiconductor device is provided with a clock signal generation circuit that includes a reference clock signal generation circuit which generates a first reference clock signal, a first counter circuit which counts the number of rising edges of the first reference clock signal by using the first reference clock signal and a synchronizing signal, a second counter circuit which counts the number of rising edges of the first reference clock signal by using an enumerated value of the first counter circuit, a first divider circuit which divides a frequency of the first reference clock signal by using the enumerated value of the first counter circuit and generates a second reference clock signal, and a second divider circuit which divides a frequency of the second reference clock signal and generates a clock signal.

A serializer receives parallel data and a control signal. The serializer splits the parallel data into multiple subportions of data and, based on the control signal, sequentially outputs each of said subportions as serial output data in one or more serial output channels. The number of serial output channels is dictated by the control signal.

A DLL of a memory device having a normal mode and a power down mode includes a clock buffer for buffering an external clock signal to output an internal clock signal. A power down mode controller generates a power down mode control signal to define the normal mode or the power down mode in response to a clock enable signal. A source clock generation unit receives the internal clock signal to generate a DLL source clock signal under the control of the power down mode control signal. A phase update unit performs a phase update operation based on the DLL source clock signal to output a DLL clock signal.