Abstract: A frequency divider and a control method thereof are provided. The frequency divider includes a phase selector and a control circuit. The phase selector receives N input signals, and selects a first input signal from the N input signals as an output signal according to N selection signals. The frequency of the N input signals are the same, and the phase of the N input signals are different, and every adjacent two of the N input signals have a phase difference of 360°/N, wherein N is a positive integer larger than 2. The control circuit updates the N selection signals according to the output signal, such that the phase selector switches the output signal from the first input signal to a second input signal of the N input signals, wherein the phase of the second input signal leads the phase of the first input signal by 360°/N.

Abstract: One or more gray code counters, counter arrangements, and phase-locked loop (PLL) circuits are provided. A gray code counter comprises a set of cells, such as standard cells, that output a gray code signal. The gray code counter comprises a pre-ready cell that provides an early signal, generated based upon an early clock, to one or more cells to reduce delay. A counter arrangement comprises one or more counter groups configured to provide pixel count levels for pixels, such as pixels of an image sensor array. A counter group comprises a gray code counter configured to provide a gray code signal to latch counter arrangements of the counter group. A PLL circuit comprises a gray code counter configured to generate a gray code signal used by a digital filter to adjust an oscillator. The gray code signal provides n-bit early/late information to the digital filter for adjustment of the oscillator.

Abstract: An electric circuit includes: a reference signal generation circuit that generates a reference signal based on a first oscillation signal that is an oscillation signal of a first oscillation circuit that vibrates a first vibrator; and a counter circuit that counts a second oscillation signal that is an oscillation signal of a second oscillation circuit that vibrates a second vibrator based on the reference signal, and outputs a count signal, wherein the count signal is a change of the count value in the second oscillation signal.

Abstract: Digital logic processing devices capable of reduced power consumption may be provided. A digital logic processing device may include one or more processing elements, an input FIFO for storing data, a processing unit, and a clock controller circuit. The processing unit may process data from the input FIFO and the clock controller circuit may control a clock signal supplied to the input FIFO and the processing unit. The clock controller circuit may monitor whether there is data to be transferred to the input FIFO and states of the input FIFO and the processing unit and may control the clock signal.

Abstract: The invention relates to an apparatus comprising a pipelined converter, such as a pipelined ADC. The pipelined converter has a first set of stages and a second set of stages. A clocking circuit is configured to generate a plurality of clocking signals for the pipelined converter. The plurality of clocking signals comprise a first clocking signal at a first voltage level that is provided to the first set of stages and a second clocking signal at a second voltage level that is provided to the second set of stages.

Abstract: In one embodiment, a method for balancing clock signals in a clock tree includes, at a register, receiving a divided input clock signal and a non-divided input clock signal and generating a first output clock signal based on the received divided input clock signal and the received non-divided input clock signal, the first output signal being associated with a first delay. The method further includes, at a delay line, receiving the non-divided input signal, delaying the non-divided input signal for a time substantially equivalent to the first delay, and generating a second output clock signal associated with a second delay substantially equal to the first delay.

Abstract: An integrated circuit, such as a programmable logic device, implements a single bit transition counter in logic. The counter preferably comprises a first stage receiving a clock signal having a first clock rate and generating a least significant bit in a count. A plurality of intermediate stages are coupled to the first stage, where each intermediate stage receives an output from the immediate previous stage and an inverted output of each other previous intermediate stage, and generates a next most significant bit in a count. Finally, a last stage of the counter receives an inverted output of each previous intermediate stage except the immediate intermediate previous stage and generating a most significant bit in a count.

Abstract: A high speed binary counter includes a counting first flip-flop for each binary bit, a single AND gate for each lower order binary bit beyond B0 and B1, and at least two AND gates for each higher order binary bit. The counter also includes an input factor delay second flip-flop. The counter is further provided with a mechanism for redundant least significant terms for lesser order bits.

Abstract: A counter having enhanced counting speed is provided. The counter includes first through N-th output signal generators. The first output signal generator responds to a clock signal and outputs a first output signal in which a low level and a high level are output once per cycle of the clock signal. The second output signal generator responds to the clock signal and the first output signal and outputs a second output signal in which a low level and a high level are output every two cycles of the clock signal. The third output signal generator responds to the clock signal and the second output signal and outputs a third output signal in which a low level and a high level are output every four cycles of the clock signal. The N-th output signal generator responds to the clock signal and the N?1th output signal and outputs an N-th output signal in which a low level and a high level are output every 2N?1 (where N is a natural number greater than 1) cycles of the 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: 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 real time clock counter includes a serially connected plurality of register units, each register unit having a bit register for storing clock data, a half adder for incrementing the clock data stored in the bit register, and an activation circuit for activating the bit register. Each activation circuit includes a first input for receiving an oscillating timing signal and a second input for receiving a binary carry term from the previous bit register unit's half adder. Each activation circuit also includes an output for outputting a first activation signal or a second activation signal according to the first value and the oscillating timing signal such that when the activation circuit outputs the first activation signal, the bit register is activated, and when the activation circuit outputs the second activation signal, the bit register is not activated, saving power.

Abstract: A reset circuit outputting a reset signal /RESET when detecting an abnormal state in a ring counter is provided. The reset circuit divides the outputs of flip-flops constituting the ring counter into two groups, and check if either of the groups has “H” data. When “H” data exists in both of the two groups or when “H” data does not exist in either of the two groups, the reset circuit activates the reset signal /RESET to L level. Therefore, a semiconductor device can detect an erroneous state and recover to a normal state quickly.

Abstract: A synchronous counter circuit having a plurality of bit counting stages, each corresponding to a bit position for representing counts, from a least significant bit to a most significant bit. Each bit counting stage includes a flip-flip circuit and a synchronization circuit and each includes circuitry for receiving a pulse train clock signal, synchronously counting said clock signal and outputting an output bit signal corresponding to said counters' stage bit position. The bit counting stages are arranged in two groups, a reset group and a counting group, such that the output bit signal of said flip-flop circuit of the reset group synchronizes data propagation between each bit counting stage of the counting group.

Abstract: A synchronous counter comprises one D flip-flop circuit for performing divide-by-2 frequency division of a clock signal CK, JK flip-flop circuits for, when input signals have HIGH levels (logical value 1), inverting the levels of the output signals in synchronization with the clock signal CK, logic circuits for inputting control signals to the JK flip-flop circuits, lower-stage signal assembling circuits for grouping the output signals from the JK flip-flop circuits into two-signal-unit groups to produce logical product signals of the signals in these two,signal-unit groups, and upper-stage signal assembling circuits for further handling the output signals from the lower-stage signal assembling circuits, thereby firstly simultaneously satisfying an increase in speed of the counting operation as well as simplification of the wiring pattern and reduction in the circuit area and secondly realizing further increase in the counting operation.

Abstract: A frequency divider includes a transmission gate having input and output terminals and a gate terminal to which a single-phase clock signal is applied to turn off and off the transmission gate; an element having an input terminal connected to the output terminal of the transmission gate for inversion, delay and amplification of a signal input to the input terminal of the element to produce an output signal and outputting the output signal to the input terminal of the transmission gate; and a frequency divider output terminal connected to the output terminal of the element and to the input terminal of the transmission gate for outputting a signal having a frequency equal to 1/n (n=integer) of the frequency of the clock signal. Since the frequency divider includes one transmission gate and one element, the delay time of the critical path required for inverting the produced frequency-divided signal is reduced so that accurate frequency division is performed with a high-speed clock.

Abstract: A counter circuit converts a full count to a zero count and a zero count to a full count. An incrementing counter circuit according to the present invention has a plurality of threshold circuits with stepwise thresholds. An output of the highest threshold circuit is used as a cut off signal for other threshold circuits. A decrementing counter circuit according to the present invention has a plurality of threshold circuits from the lowest threshold to the highest thresholds. An output of the lowest threshold circuit is used as a closing signal for other threshold circuits.

Abstract: An integrated circuit is provided for reducing scale of flip-flops which can be connected in the form of a shift register by the switching operation, in order to facilitate the test during the manufacture of an integrated circuit (gate array). One selector for switching a clock signal for the flip-flops to either of a system clock signal and a scan clock signal is provided not for each of the sequential circuits, but for each of the clock systems for these sequential circuits. In a case of a gate array, for example, this allows a reduction of three gates for each flip-flop to be realized.

Abstract: Conventional microprocessors await the data on the bus for acceptance for a given number of processor clock signals after accessing an external device, notably after a read instruction for an external data memory. When a comparatively slow memory is used in conjunction with a fast microprocessor, it may occur that the data is not yet present at the anticipated instant. In microprocessors in which no hold state is provided it is known to reduce the clock frequency during the reading of the external memory until the data is actually available. However, this results in a fluctuating mean clock frequency of the microprocessor so that internal timing members, controlled by the clock, cannot determine defined periods of time. In accordance with the invention, the clock frequency is reduced during the part of the operating cycle of the microprocessor during which an external device can be accessed, the microprocessor operating at the maximum clock frequency during the remainder of the cycle.

Abstract: A digital pulse processing device is capable of selecting desired precision. The digital pulse processing device includes a counter group for counting pulses output from a pulse output device, the counter group having a plurality of counters A and B that can be separated from and coupled with each other, a mode control circuit for instructing separation and coupling of the counters A and B, and a control circuit for separating and coupling the counters A and B in accordance with the instruction of the mode control circuit. An overflow condition of the free-run counter B is detected using an overflow flag. Detection of an overflow is conducted by setting the flag when an overflow condition has occurred twice or more. The flag is reset by rewriting the state of the flag by a software. An overflow condition which has occurred for the first time is detected in the conventional manner and is treated as carry or borrow.

Abstract: A logic circuit for outputting signals corresponding to an input signal depending on a clock signal sent from an external source includes at least one synchronous flip-flop being synchronized with the clock signal, so that the flip-flop latches the input signal, and a unit for controlling an input of the clock signal to the flip-flop based on a difference between logic levels of an output signal of the flip-flop and an input signal newly latched by the flip-flop.

Abstract: A digital frequency detection circuit, or frequency discriminator, is implemented for use as a synchronization field detector for the synchronization field frequency in the data stream read from a computer floppy disk. No analog components are utilized; and the detector produces an output indicative of the presence of a valid synchronization field frequency whenever the incoming data pulses fall within a predetermined range of frequencies having a lowest frequency limit and an upper frequency limit. This is accomplished by employing a multi-stage binary counter for counting the reference clock pulses from a computer. The counter is reset each time an incoming data pulse is received; and the outputs of the counter are coupled to coincidence gates, which establish the lowest and highest frequency limits of the predetermined range of frequencies to be detected.

Abstract: A Gray Code counter is provided having synchronous, modular circuits for each of the three types of bit positions, i.e., least significant bit ("LSB"), most significant bit ("MSB") and middle bit ("MB"). One LSB and MSB circuit each are used with as many MB circuits in between as are necessary to provide a counter having the desired number of bits. The LSB, MSB and MB circuits' designs are truly modular in that duplicate MB circuits can be freely coupled together between an LSB circuit and an MSB circuit to provide the desired number of counter bits without modifying any input or output interfaces between the circuits. The counter can count either up or down in accordance with a normal Gray Code sequence.

Abstract: High speed synchronous counters are constrained to operate within certain speeds due to delays inherent in the counter configurations. By utilizing look-ahead carries, that is, producing carry signals in anticipation of when they might be required, much of the delay can be eliminated. Speed performance can be further improved by fashioning the look-ahead carry system from programmable gate arrays, where non-standard logic structures can be created.

Abstract: A high speed counter circuit for counting electrical pulses includes a master/slave flip-flop at the input stage of the counter. An AND gate logically ANDs the pulses being counted with the master output to produce a first gating signal. A plurality of cascade coupled flip-flops each having a slave and an inverse slave output are provided. The clock input to each cascade coupled flip-flop is produced by the logical OR of the electrical pulses being counted, the first gating signal and the slave output of all preceding flip-flops of the counter. The counter output is provided by the inverse slave output of each flip-flop.

Abstract: A look ahead terminal counter and a method for generating a terminal count output signal are disclosed. The counter comprises a plurality of counter registers connected to counter enable circuitry for sequencing the registers at a predetermined counter rate. Terminal count enable circuitry is connected to the counter circuitry, e.g. at the input ports of the counter registers, and is operative to generate a terminal count enable signal when those input ports are at a predetermined state. The terminal count enable signal and clock signal are communicated to an output register operative to generate a terminal count output signal when a clock signal is received during the simultaneous presence of the terminal count enable signal.

Abstract: Integrated circuits having a large number of transmission gate logic stages have been found to draw a large current surge on power-up. This is due to the floating input node of complementary inverters causing current to flow briefly before clock pulses arrive. The present invention provides a DC voltage on the gates of the pass transistors until the system clock pulses arrive, thereby eliminating the floating node. An optional periodic window may be generated to examine the system clock after power-up, to detect a loss of clock condition.

Abstract: A synchronous binary circuit comprising a counter including J-K flip-flops constituting lower l bit stages and higher m bit stages, first logic means for feeding, to J and K input terminals on each of flip-flops among the lower l bit stage flip-flops higher than the second bit stage, an AND of non-inverted outputs of all the lower stage flip-flops than the pertinent stage, second logic means for feeding, to the J and K input terminals of the first stage flip-flops among the higher m bit stage flip-flops, a first logical product of the non-inverted output of a one bit lower stage flip-flop and non-inverted outputs of the first to (l-1)-th bit stage flip-flops among the lower bit stage flip-flops, and third logic means for feeding, to the J and K input terminals of flip-flops among the higher m bit stage flip-flops higher than the second stage, a second logical product of non-inverted outputs of the lower first to (l-1)-th bit stage flip-flops and a third logical product, the third logical product being a logic

Abstract: A binary synchronous bit-sliced counter comprising a plurality of cascaded identical stages (slices). Each stage only requires for its operation a source of potential V.sub.dd, a carry-in signal input line, a clock signal input line, a reset signal input line and a carry-out signal output line. Cascading of the slices is implemented by connecting the carry-out signal output line of one slice to the carry-in signal input line of another slice and connecting the clock signal and reset signal input lines to all cascaded stages in parallel.

Abstract: A counter/divider apparatus employing an array of counters arranged in parallel. Each counter repeatedly counts through a sequence of a number of clock pulses. The number is different for each counter and the numbers are relatively prime numbers. The outputs of the counters are applied to a detector that recognizes a preset combination of output signals which is present after a predetermined number of clock pulses have been received. The detector then produces an output pulse which clears all the counters to their initial states, and the cycle is repeated. The apparatus thus divides the input clock pulses by the aforementioned predetermined number.

Abstract: A first 5-stage ring counter generates a signal having a frequency of (4/5)f.sub.SC by dividing a frequency 8f.sub.SC of a signal. A second 5-stage ring counter generates a signal having a frequency of (4/5)f.sub.SC by dividing a frequency of a signal obtained by inverting the signal of frequency 8f.sub.SC by an inverter. A first sampling pulse output circuit generates a first sampling pulse from an output signal from the first 5-stage ring counter. A second sampling pulse output circuit generates a second sampling pulse from an output signal from the second 5-stage ring counter. A phase correction circuit causes synchronization of the count operation of the first 5-stage ring counter with a clock run-in signal. This phase correction is performed by shifting the phase of the output from the first 5-stage ring counter in units of the period of the signal of frequency 8f.sub.SC.

Abstract: A binary counter consists of a plurality of unit stages each having a bistable circuit, a buffer circuit for generating an output corresponding to an output state of the bistable circuit, a switching circuit for supplying an output of the buffer circuit to the bistable circuit, and a coincidence gate for supplying a clock signal to the next unit stage in accordance with the predetermined output state of the bistable circuit.

Abstract: A ripple counter circuit is provided that reduces propagation delay inherent in flip-flops, and therefore, reduces the current required. A first flip-flop has a clock input responsive to a clock signal and a D input connected to a Q output. A second flip-flop has a clock input ANDed to a Q output of the first flip-flop and the clock signal. A propagation delay normally associated with the first flip-flop is eliminated from the Q output of the second flip-flop.

Abstract: A parallel-serial converter comprises a plurality of selection-delay unit circuits. The unit circuit selectively receives an output signal from the immediately preceding unit circuit and one of a plurality of input parallel signals and shifts the selectively received signal to the immediately succeeding unit circuit. The selection-delay unit circuit is only formed of three transfer gates and two inverters in order to reduce a chip size and save power consumption.