A frequency divider circuit includes: a first frequency dividing circuit configured to divide a first clock signal to generate a first frequency-divided clock signal; a second frequency dividing circuit configured to divide a second clock signal having the same frequency as the first clock signal and having a first phase difference with respect to the first clock signal to generate a second frequency-divided clock signal; a detection circuit configured to detect a phase relationship between the first frequency-divided clock signal and the second frequency-divided clock signal; and a selection circuit configured to select and output one of the second frequency-divided clock signal and an inverted signal of the second frequency-divided clock signal which are generated by the second frequency dividing circuit, based on the phase relationship between the first frequency-divided clock signal and the second frequency-divided clock signal detected by the detection circuit.

Apparatuses, systems and methods associated with bidirectional Gray code counter design are disclosed herein. In embodiments, a bidirectional Gray code counter may include a sequential logic element to store a Gray code value and logic circuitry. The logic circuitry may be to determine, based on a bidirectional indicator signal, whether to increment or decrement the Gray code value update, through performance of an increment or a decrement of the Gray code value based on the determination of whether to increment or decrement the Gray code value, the Gray code value to be a sequential Gray code value and replace the Gray code value stored in the sequential logic element with the updated Gray code value. Other embodiments may be described and/or claimed.

An electronic circuit comprises: an input terminal; an output terminal; first and second supply rails; first, second, third, and fourth field effect transistors, FETs, each of a first type and each having respective gate, source and drain terminals; and first and second loads. The source of the first FET is connected to the first supply rail, the drain of the first FET and the source of the second FET are connected to the output terminal, the drain of the second FET is connected to the second supply rail, the gate of the third FET and the gate of the fourth FET are connected to the input terminal, the drain of the third FET is connected to the second supply rail, the first load is connected between the first supply rail and the source of the third FET, and the second load is connected between the drain of the fourth FET and the second supply rail. In one aspect of the invention, the gate of the first FET is connected to a node between the source of the third FET and the first load such that a voltage at the source of the third FET is applied to the gate of the first FET, and the gate of the second FET is connected to a node between the drain of the fourth FET and the second load such that a voltage at the drain of the fourth FET is applied to the gate of the second FET.

A first counter is incremented when a first rotational speed sensing device detects a falling edge of one of the teeth of a single multi-tooth target wheel, a second counter is incremented when a second rotational speed sensing device detects a falling edge of one of the teeth, and a third counter is incremented when either of the first and second rotational speed sensing devices detects either of a rising edge and a falling edge of one of the teeth. A direction of rotation is determined based upon the third counter and a rotational speed of the rotatable member is determined based upon one of the first and second counters. The rotatable member is indicated to be at zero speed when the rotational speed is less than a threshold speed and the direction of rotation changes between a positive direction and a negative direction.

This invention comprises a new way to connect a control, CK, and data, D, signal into a basic cross-coupled INV pair, and into certain other basic sequential logic circuits, to control the writing in of a new data value, D, into the sequential logic circuit cell. The invention concerns logic circuit in complementary metal-oxide-semiconductor (CMOS) technology. It connects additional p-type and n-type MOSFET devices in a novel manner to accomplish the desired control functions.

In described examples, a counter system includes a counter, a parity detector, a toggle flop, and a comparator. The counter iterates a count through a set of binary states in response to a clock signal, so that a binary value of a single bit of the count changes at each iteration. The parity detector detects the parity of the count. The toggle flop output is coupled to the toggle flop input. The toggle flop outputs a binary flop value. The binary flop value toggles between zero and one in response to the toggle flop input and the clock signal. The comparator compares the parity of the count and the toggle flop output, and outputs a first comparator value if the parity of the count and the toggle flop output are the same, and a second comparator value if the parity of the count and the toggle flop output are different.

The present disclosure provides a low-jitter frequency division clock circuit, including: a clock control signal generation circuit, to generate clock signals having different phases; a low-level narrow pulse width clock control signal generation circuit, to generate a low-level narrow pulse width clock control signal; a high-level narrow pulse width clock control signal generation circuit, to generate a high-level narrow pulse width clock control signal; and a frequency division clock generation circuit, to generate a frequency division clock signal according to low-level narrow pulse width clock control signal and high-level narrow pulse width clock control signal. The delay from a clock input end to an output end of low-jitter frequency division clock circuit is up to three logic gates. Compared with traditional divide-by-2 frequency division clock circuits based on D-flip-flop, the low-jitter frequency division clock circuit of the present disclosure has fewer logic gates, a shorter delay, and lower jitter.

In an embodiment, a method includes: providing a gray-coded time reference to a time-to-digital converter (TDC); receiving an event from an event signal; latching the gray-coded time reference into a memory upon reception of the event signal; and updating a time-of-flight (ToF) histogram based on the latched gray-coded time reference.

A hybrid true single-phase clock (H-TSPC) circuit includes a first logic circuit comprising non-ratio (NR) logic, a first mode switching device coupled to an output of the first logic circuit, a second logic circuit comprising ratio (R) logic, the second logic circuit configured to receive an output of the first logic circuit, a second mode switching device coupled to an output of the second logic circuit, a third logic circuit comprising non-ratio (NR) logic, the third logic circuit configured to receive an output of the second logic circuit, and a third mode switching device coupled to an output of the third logic circuit, wherein the first logic circuit, second logic circuit, and third logic circuit are configured in a ring.

A multi-bit gray code generation circuit includes: a zeroth bit gray code generation circuit configured to generate a gray code corresponding to a bit 0 of a multi-bit gray code; and a plurality of gray code generation circuits each configured to generate a gray code corresponding to each bit higher than the bit 0 of the multi-bit gray code. Each of the plurality of gray code generation circuits is constituted by a plurality of flip-flop circuits. An output of a flip-flop circuit in the previous stage is input to a flip-flop circuit of the next stage. An output of a flip-flop circuit of the final stage is inverted and held by a flip-flop circuit of the first stage. An output of one of the plurality of flip-flop circuits is output as a gray code corresponding to each bit.