Abstract: A frequency divider is provided that includes a plurality of latches for dividing an input clock according to an integer frequency divisor N of three or greater. Each latch is coupled to a corresponding pair of logic gates. For each latch, one of the logic gates in the corresponding pair controls a setting of the latch whereas a remaining one of the logic gates in the corresponding pair controls a resetting of the latch. Each latch outputs a pair of overlapping clock signals that are divided in frequency with respect to the input clock and have a 50% duty cycle. Each logic gate processes a pair of the overlapping clock signal and the input clock signal to provide a non-overlapping clock signal of the same frequency of the overlapping clock signals but have a (50/N) % duty cycle.

Abstract: A counting circuit includes first to fifth flip-flops (FFs) and a logic operation unit. Each of the first to fourth FFs has an initial value based on a preset control signal input through a 4-bit set terminal and outputs a signal according to a clock signal. The fifth FF is coupled to the output terminal of the fourth FF and is configured to output the output signal of the fourth FF synchronously with the clock signal. The logic operation unit logically combines the output signals of the second to fourth FFs and outputs first and second counting signals.

Abstract: A latency counter of a semiconductor device comprises a single cyclic signal generator and a command delay circuit. The single cyclic signal generator cyclically produces 0-th to n-th base signals based on an internal clock signal. The command delay circuit comprises 0-th to n-th latch elements and latches an internal command by means of a p-th latch element (p is an integer; 0?p?n) in response to a q-th base signal (q is an integer; 0?q?n) and to output the latched internal command corresponding to the latency timeout signal therefrom in response to a r-th base signal (r is an integer; 0?r?n), where r=q+s if q+s?n, while r=q+s?(n+1) if q+s>n, s being a natural number equal to or less than n.

Abstract: Described are fast synchronous counters with reduced combinatorial logic. In one embodiment, a four-bit shift register is configured in a ring and preset with a data pattern (e.g., 1000). The register is then rapidly shifted into any of four unique states. Combinatorial logic connected to the shift register converts the four unique states into a two-bit binary signal representative of the four states. In the general case, counters in accordance with this embodiment represent N-bit binary numbers using 2N synchronous storage elements. Two or more counters can be combined to produce larger synchronous counters. An up/down counter in accordance with yet another embodiment is connected to a multi-path delay line to create a variable delay circuit. The switching speed of the delay circuit is independent of the number of delay settings. Also advantageous, the delay circuit scales linearly, in terms of power consumption and area, with changes in delay granularity.

Abstract: Described are fast synchronous counters with reduced combinatorial logic. In one embodiment, a four-bit shift register is configured in a ring and preset with a data pattern (e.g., 1000). The register is then rapidly shifted into any of four unique states. Combinatorial logic connected to the shift register converts the four unique states into a two-bit binary signal representative of the four states. In the general case, counters in accordance with this embodiment represent N-bit binary numbers using 2N synchronous storage elements. Two or more counters can be combined to produce larger synchronous counters. An up/down counter in accordance with yet another embodiment is connected to a multi-path delay line to create a variable delay circuit. The switching speed of the delay circuit is independent of the number of delay settings. Also advantageous, the delay circuit scales linearly, in terms of power consumption and area, with changes in delay granularity.

Abstract: A fault state detector for a ring counter is formed from unit current sources each switched under the control of a different one of the outputs of the ring counter. The currents switched in that manner are passed through a unit resistance to generate a voltage signal proportional to the number of asserted outputs from the ring counter. The voltage signal is compared to boundary reference values for valid states of the ring counter outputs and, if the voltage signal is not between the boundary reference values, a fault state is indicated.

Abstract: A non-integer frequency divider is disclosed. The non-integer frequency divider circuit includes several base stages connected to each other. The non-integer frequency divider circuit also includes a clocking circuit for passing an enable bit from one of the base stages to another such that only one of the base stages is enabled at any give time. The enable bit has a pulse width of one clock cycle. The outputs from the base stages are grouped together by an OR gate to generate a single output that is a fraction of an input clock signal.

Abstract: Described are fast synchronous counters with reduced combinatorial logic. In one embodiment, a four-bit shift register is configured in a ring and preset with a data pattern (e.g., 1000). The register is then rapidly shifted into any of four unique states. Combinatorial logic connected to the shift register converts the four unique states into a two-bit binary signal representative of the four states. In the general case, counters in accordance with this embodiment represent N-bit binary numbers using 2N synchronous storage elements. Two or more counters can be combined to produce larger synchronous counters. An up/down counter in accordance with yet another embodiment is connected to a multi-path delay line to create a variable delay circuit. The switching speed of the delay circuit is independent of the number of delay settings. Also advantageous, the delay circuit scales linearly, in terms of power consumption and area, with changes in delay granularity.

Abstract: A synchronous counter includes at least three or more flip-flops having a chain structure, and at least two or more 2-input EXOR gates interposed in the chain structure. The number of stages of gates interposed between the output of one among the flip-flops and the input of another is one stage of a 2-input EXOR gate even in a critical path thereby shortening the critical path.

Abstract: A non-integer frequency divider that is capable of dividing an original clock frequency by a non-integer number into a desired target clock frequency. By this non-integer frequency divider, a phase-shifting circuit is first used to convert the original clock frequency into a predetermined number of phase-shifted versions of the original clock frequency with a predetermined phase difference. Then, a plurality of edge-triggered clock signal generators are used to generate a plurality of edge-triggered signals whose rising and falling edges are synchronized with the original clock frequency and its phase-shifted versions. Finally, a synthesis circuit is used to synthesize the edge-triggered signals into an output signal serving as the intended target clock frequency.

Abstract: There is provided a synchronous counter comprising: at least three or more flip-flops having a chain structure; and at least two or more 2-input EXOR gates interposed in the chain structure, wherein the number of stages of gates interposed between the output of one among the flip-flops and the input of another is one stage of a 2-input EXOR gate even in the most path, thereby shortening the critical path.

Abstract: An initial value generation circuit generates an initial value taking into consideration the a time delay when a signal is transmitted through the signal wires between a pilot device and other devices, and a processing delay caused in respective devices. When a device receives a system synchronizing signal form another device, the device sets an initial value in a counter. Thereby, the counter value of a counter in a pilot device and counter values of counters in the other devices are made to coincide with each other.

Abstract: A digital delay generator device is based on a series arrangement of cells, wherein each cell has a first input for receiving a single-phase clock signal, a second input for receiving a delayable signal for thereto imparting a cell delay, and an output for a so-delayed signal. Each cell comprising a series stack of transistors, and various cells comprise further transistor means for receiving a bypass control signal. Such further transistor means are arranged for under control of a bypass control signal effectively bypassing one or more cells to thereby effect a quantized overall delay shortening. In particular, such various cells form a contiguous pair in said string, and the transistor means effectively form respective transistor bypasses over clock-signal-controlled transistors in the associated series stack at mutually opposite sides of their respective stack.

Abstract: A sequential logic circuit includes N state hold circuit where N is an integer. Each of the state hold circuits has a first input terminal, a second input terminal and an output terminal. The state hold circuits are cascaded via the respective first input terminals. The second input terminals of the state hold circuits receive a first clock signal. The first input terminal of one of the state hold circuits in a first stage receives a data signal. The output signal is obtained via the output terminal of one of the state hold circuits in a final stage.

Abstract: A logic and memory family using CMOS technology operates at high speeds using a Ring Segment Buffer to couple logic gates to one another in an integrated circuit chip, and to couple memory cells to other circuits to provide shift registers, triggers, clock pulse generators and other memory related circuits. The Ring Segment Buffer comprises one or more serially connected complementary field effect transistor (FET) inverter stages, with the output of a preceding stage being connected to the input of a succeeding stage. The N-channel FET in each inverter stage has a channel width which is less than a predetermined factor (K) times the width of the N-channel of the immediately preceding stage. By maintaining the K channel width relationship, the Ring Segment Buffer can drive large capacitive loads at high speed. The Ring Segment Buffer may also provide a predetermined delay which is a function of channel length and the number of stages.

Abstract: A logic and memory family using CMOS technology operates at high speeds using a Ring Segment Buffer to couple logic gates to one another in an integrated circuit chip, and to couple memory cells to other circuits to provide shift registers, triggers, clock pulse generators and other memory related circuits. The Ring Segment Buffer comprises one or more serially connected complementary field effect transistor (FET) inverter stages, with the output of a preceding stage being connected to the input of a succeeding stage. The N-channel FET in each inverter stage has a channel width which is less than a predetermined factor (K) times the width of the N-channel of the immediately preceding stage. By maintaining the K channel width relationship, the Ring Segment Buffer can drive large capacitive loads at high speed. The Ring Segment Buffer may also provide a predetermined delay which is a function of channel length and the number of stages.

Abstract: A high speed CMOS divide by 4/5 prescaler circuit comprises first, second, third, fourth, and fifth inverter stages. When a modulas control signal is low, the prescaler operates as five clocked inverters in series having an output which is fed back to the input of the initial stage. That is, the circuit operates as a five stage clocked ring oscillator wherein only one output changes on each clock edge. When a modulas control signal is high indicating that a divide by four is desired, the counter operates as a five stage ring oscillator for seven clock edges. On the eighth edge, feed forward circuitry forces the last three stages to change states simultaneously.

Abstract: A clock generating circuit having at least one loop of at least two stages. Each stage consists of a pass transistor serially connected to an inverter. An inverter couples the end of the loop to its beginning. The gate electrodes of the transistors in the serially connected stages are controlled alternatively by a true and a complemented clock signal. Preferably, there are two such loops operating in parallel but which include initialization circuitry that initializes the two loops to complementary values.

Abstract: The ring counter of this invention is self-initializing and is operable at a clock frequency corresponding to four gate delays and comprises a plurality of master of slave flip-flops, in which this high speed capability is attained by using non-inverting feedback between the first and last flip-flops and by operating the master and slave of each in complementary fashion without requiring the use of a complementary clock signal. The non-inverting feedback takes advantage of the inherent delay between the response of the complementary outputs of each flip-flop.