Intel Corporation

Micron Technology Incorporated

Fangxing Wei

Michael J Allen

Dan Shi

Khushal Chandan

Setul M Shah

Subratakumar Mandal

Arif Mahmud

Ashish Gupta

Yongping Fan

Edward R Helder

Chengting Zhao

Digital delay locked loop circuits, devices systems, and associated methods are provided and described. Such devices, systems, and methods utilize an open loop measurement for establishing a coarse delay lock.

Coarse delay lock estimation for digital DLL circuits

Methods, systems, and devices for jitter cancellation with automatic performance adjustment are described. Within a clock distribution system in an electronic device (e.g., a memory device), a jitter cancellation system may be configured to introduce delay between an input clock signal and output clock signal that is directly proportional to the supply voltage for the clock distribution system. In response to supply noise, the delay introduced by the jitter cancellation system may vary directly with respect to the supply voltage fluctuations and thus may offset fluctuations in the delay introduced by other components of the clock distribution system, which may vary inversely with respect to the supply voltage fluctuations. A control component within the jitter cancellation system may execute an algorithm to adjust or regulate the delay introduced by the jitter cancellation system, including its responsiveness to fluctuations in the supply voltage.

Jitter cancellation with automatic performance adjustment

Phase compensation in an I/O (input/output) circuit includes variable, programmable slope. A phase compensation circuit can apply phase compensation of one slope and dynamically change the slope of the phase compensation to allow for better tracking of environmental conditions. The phase compensation circuit can generate a linear code to apply phase compensation to lock phase of an I/O signal to a phase of a timing signal. The circuit selectively adjusts the linear code with a variable, programmable slope, where the slope defines how much phase compensation is applied per unit change in the linear code. The circuit applies the adjusted linear code to a lock loop to lock the phase of the I/O signal to the phase of the timing signal.

Digital phase control with programmable tracking slope having a programmable linear decoder using a coarse code and a fine code to generate delay adjustments to the phase of an input signal

Technology for a phase detector is described. The phase detector can include a reference clock. The phase detector can include a feedback clock. The phase detector can include a first latch operable to set a first latch output depending on a lead-lag status between the reference clock and the feedback clock. The phase detector can include a second latch that loads the lead-lag status when the reference clock and the feedback clock produce clock signals in a high state. The phase detector can include a third latch that loads the lead-lag status from the second latch when the reference clock and the feedback clock produce clock signals in a low state.

Phase detector in a delay locked loop

Examples may include techniques for dual-range clock duty cycle tuning of a clock signal used for an input/output data bus. A clock duty cycle of the clock signal is monitored to determine whether the clock duty cycle falls within a threshold of a 50 percent duty cycle. A dual-range tuning is then implemented until the clock duty cycle of the clock signal falls within the threshold.

Dual-range clock duty cycle corrector

Digital phase control with programmable tracking slope

A glitch-free digitally controlled oscillator (DCO) code update may be achieved by synchronizing the transfer of the DCO code update to a logic state transition of a pulse in the DCO clock output signal such that the code update may be achieved while the DCO delay chain remains in the same logic state. A state machine may provide the DCO code update and a pulsed update signal to a timing circuit. The DCO code update may be aligned with a pulse in the pulsed update signal. The timing circuit may generate a DCO code update enabled signal upon alignment of the pulse in the pulsed update signal with a state transition of a pulse in the pulsed DCO clock output. The DCO code update enabled signal may be aligned with a state transition in the pulsed DCO clock output to permit a glitch-free DCO code update.

Glitch-free digitally controlled oscillator code update

Phase compensation in an I/O (input/output) circuit includes a triangular control contour with a simplified generation circuit. A linear control circuit can generate a digital N-bit linear count, and route the least significant M bits [(M&#x2212;1):0] for linear control for fine delay mixing of a phase compensation loop and the most significant (N&#x2212;M) bits [(N&#x2212;1):M] for linear control for coarse control of a delay chain for the phase compensation loop. Prior to decoding the least significant M bits for fine delay mixing, the control circuit performs a bitwise XOR (exclusive OR) of bit M with each of bits [(M&#x2212;1):0] to generate M linear control bits as the linear control for fine delay mixing. The M linear control bits generate a linear control count having a triangular contour, where the linear control count continuously, repeatedly counts from 0 to (2&#x2212;1) to 0.

XOR (exclusive or) based triangular mixing for digital phase control

A DLL may include a DLL training circuit that provides a feedback signal to the DLL and receives a first delay code value from the DLL that corresponds to the delay added to the feedback signal to align a leading edge transition in the feedback signal with a leading edge transition in the reference clock signal. The DLL training circuit further provides an inverted feedback signal to the DLL and receives a second delay code value from the DLL that corresponds to the delay added to the inverted feedback signal to align a leading edge transition in the inverted feedback signal with a leading edge transition in the reference clock signal. The DLL selectively adds the delay code corresponding to the temporally smaller of the first delay code value or the second delay code value to the feedback signal to align the feedback signal with the reference clock signal.

Digital delay-locked loop (DLL) training

A temperature compensation apparatus may include a sense circuit configured to produce a sense voltage that is dependent on temperature and a temperature compensation circuit configured to receive the sense voltage and produce a temperature compensation control signal to control a compensation capacitor array of an oscillator. The temperature compensation circuit may be configured to calibrate the control signal to have a first value at a first temperature. The temperature compensation circuit may also be configured to calibrate a trimming level (e.g., slope) of the control signal.

Temperature compensation for oscillator

Methods and apparatus for improving system timing margin of high speed I/O (input/output) interconnect links by using fine training of a phase interpolator are described. In some embodiments, I/O links use forward clock architecture to send data from transmit driver to receiver logic. Moreover, at the receiver side, Phase Interpolator (PI) logic may be used to place the sampling clock at the center of the valid data window or eye. In an embodiment, a Digital Eye Width Monitor (DEWM) logic may be used to measure data eye width in real time. Other embodiments are also disclosed.

System timing margin improvement of high speed I/O interconnect links by using fine training of phase interpolator

A novel digital eye width monitor (DEWM) system and method are disclosed. The DEWM system provides on-die capability to directly measure the left and right eye-width in picoseconds. The DEWM system measures the time from the phase interpolator (PI) clock position (data eye center, left edge, right edge) to a reference clock, and calculates the left and right eye width within a single-digit pico-second level of accuracy.

Growing community of inventors

Folsom, CA, United States of America

Fangxing Wei