Sandisk Technologies Inc.

Western Digital Technologies, Inc.

Srinivas Rajendra

Venkatesh Ramachandra

Anil Pai

Tianyu Tang

Jang Woo Lee

John Thomas Contreras

Rehan Ahmed Zakai

Sayed Mobin

Primit Modi

Systems and methods are provided for correcting errors in unmatched memory devices. Various embodiments herein train a memory interface to determine a duty cycle timing for a clock signal in a data window formed by a data signal in a memory cell. The duty cycle timing identifies an initial trained timing in the data window at which a setup portion and a hold portion of the data window are approximately equal in length when the trigger signal is received at the initial trained timing. The embodiments herein also identify an event that shifts the duty cycle timing away from the initial trained timing, and triggers a retraining of the memory interface based on a determination that at least one of two points defined about the initial trained timing fails a two-point sampling.

Systems and methods of correcting errors in unmatched memory devices

Systems and methods are provided that combine a write duty cycle adjuster with write training to reduce detection and duty cycle errors in memory devices. Various embodiments herein perform write duty cycle adjuster operations to adjust a duty cycle of a clock signal that coordinates a data signal with a data operation on the memory device based on an error in the duty cycle, and performs write training operations to detect a skew between the data signal and the clock signal and adjust a sampling transition of the duty cycle of the clock signal to align with a valid data window of the data signal.

Systems and methods of reducing detection error and duty error in memory devices

Technology is disclosed herein for semi receiver side write training in a non-volatile memory system. The transmitting device has delay taps that control the delay between a data strobe signal and data signals sent on the communication bus. The delay taps on the transmitting device are more precise that can typically be fabricated on the receiving device (e.g., NAND memory die). However, the receiving device performs the comparisons between test data and expected data, which alleviates the need to read back the test data. After the different delays have been tested, the receiving device informs the transmitting device of the shortest and longest delays for which data was validly received. The transmitting device then sets the delay taps based on this information. Moreover, the write training can be performed in parallel on many receiving devices, which is very efficient.

Semi receiver side write training for non-volatile memory system

Technology is disclosed herein for per pin internal reference voltage generation for data receivers in non-volatile memory systems. A receiving circuit may have an on-die voltage generator that has inputs to receive a separate voltage magnitude select signal for each data receiver on the receiving circuit. The on-die voltage generator provides a separate reference voltage for each data receiver. This allows the reference voltage for each data receiver to be calibrated separately. A separate reference voltage for each data receiver compensates for variations between data paths, and provides for a wider data valid window than if the same reference voltage were used for all data receivers. Generating the different reference voltages on-die can potentially require a large area, as well as consume considerable power and/or current. A voltage divider and multiplexers may provide the different reference voltages, which saves space and is power and current efficient.

Per pin Vref for data receivers in non-volatile memory system

The present disclosure generally relates to apparatuses and methods for transmission line termination. In one embodiment an apparatus includes a stack of uniform memory dies and a storage controller. Each uniform memory die in the stack of uniform memory dies couples to a transmission line in series through wire bonds to form a transmission path. Each memory die includes an on-die termination resistance circuit connected to the transmission line. The on-die termination resistance circuit provides a minimum termination resistance. The storage controller addresses a target uniform memory die of the stack of uniform memory dies for an operation. The storage controller enables the on-die termination resistance circuits of a plurality of uniform memory dies along the transmission path. The storage controller transmits a data signal for the operation to the target uniform memory die with the on-die termination resistance circuit enabled for the plurality of uniform memory dies.

Distributed grouped terminations for multiple memory integrated circuit systems

An active termination circuit comprising an input node connected to a transmission line, a first transistor, and a second transistor. The transmission line supplies a signal to the input node. The first transistor is diode connected between a high voltage supply and the input node. The first transistor terminates the signal when the signal is at a low logic level. The second transistor is diode connected between the input node and a low voltage supply. The second transistor terminates the signal when the signal is at a high logic level.

Active low-power termination

A correction system is configured to correct for duty cycle distortion and/or cross-point distortion in a pair of sample signals. A slope adjustment circuit is configured to generate a plurality of pairs of intermediate signals according to a plurality of drive strengths. A measurement circuit is configured to measure for duty cycle distortion and/or cross-point distortion, and the slope adjustment circuit is configured to set the plurality of drive strengths based on the measurement. The setting of the drive strengths may reduce certain rising and falling slopes of certain transitions of the plurality of intermediate signals, which in turn may reduce duty cycle distortion and/or cross-point distortion in the sample signals.

Duty cycle and vox correction for complementary signals

A complementary signal path may include an amplifier circuit configured to receive a pair of complementary input signals and a data alignment circuit configured to output a pair of complementary output signals in response to the pair of complementary input signals. A control circuit may detect duty cycle distortion in the pair of complementary output signals and perform a duty cycle correction process to remove the distortion. To do so, the control circuit may search for target current amounts in response to the duty cycle distortion and inject a control current into the amplifier circuit at the target current amounts.

Duty cycle correction scheme for complementary signals

Systems and methods for generating periodic signals with reduced duty cycle variation are described. In some cases, a calibration procedure may be performed prior to a memory operation (e.g., prior to a read operation or a programming operation) in which a duty cycle correction circuit receives an input signal (e.g., an input clock signal), steps through various delay settings to determine a first delay setting corresponding with a signal high time for the input signal and a second delay setting corresponding with a signal low time for the input signal, generates a delayed version of the input signal corresponding with a mid-point delay setting between the first delay setting and the second delay setting, and generates a corrected signal using the delayed version of the input signal and the input signal.

Digital pulse width detection based duty cycle correction

A circuit is presented to reduce power while transmitting high speed signals across a long length of wire on an integrated circuit. A PMOS is used as a low swing driver, where the PMOS is connected between the driver's output and ground. The gate of the PMOS is also set to ground, while the input signal is connected to the bulk. The output is then transmitted over the signal path to an analog receiver, where both single ended and differential embodiments are presented. For a single ended version, a reference voltage for the receiver can be provided by a second, similarly connected PMOS whose bulk has an input signal at an intermediate level of input swing at the transmitter PMOS.

Growing community of inventors

Milpitas, CA, United States of America

Srinivas Rajendra