Sandisk Technologies Inc.

Western Digital Technologies, Inc.

Juniper Networks, Inc.

Venkatesh Ramachandra

Tianyu Tang

Srinivas Rajendra

Masaaki Higashitani

Mohan Dunga

Anil Pai

Luisa Lin

Peter Rabkin

Vinayak Ashok Ghatawade

Hem P Takiar

Farookh Moogat

Gokul Kumar

Michael Mostovoy

Siddhesh Darne

Jang Woo Lee

James K Kai

Chih-Chin Liao

Ning Ye

Gopi Krishna

Rohini Kasturi

Piyush Dak

Primit Modi

Nikhil G Shetty

Chitrak K Ojha

Vijay S Rajaram

Nitin Kumar Gupta

John Thomas Contreras

Gautam Ashok Dusija

Rehan Ahmed Zakai

Mrinal Kochar

Shiv Harit Mathur

Elkana Richter

Ramakrishnan Subramanian

Sajal Mittal

Sneha Bhatia

Jayanth Mysore Thimmaiah

Gazal Sahai

Rampraveen Somasundaram

Ashish Savadia

Hoon Choi

George Kakuru

Siddesh Darne

In a non-volatile memory device, the amount of delay along an I/O path for transferring received data to a sense amplifier and the amount of delay along a clock path to the sense amplifier can differ. To compensate for this differential delay, a replica of each of the I/O path and the clock path can be included on the memory device. The replica circuits can be used to determine this differential delay between the two paths. To compensate for this difference, an additional delay can be introduced into one or both of the paths, such as in the I/O path, so that any difference in propagations times can be reduced.

Data path oscillator mismatch error reduction for non-volatile memory

The disclosure provides circuits and methods for increasing NAND input/output (I/O) bandwidth during read/write operations. The method includes transmitting a clock signal between a controller I/O circuit and a memory I/O circuit along a read enable bus, transmitting 8 bits of data along an I/O bus, and transmitting 2 bits of data along a data strobe signal (DQS) bus. Transmitting 2 bits of data along the DQS bus includes transmitting a first DQS data signal along the DQS bus and transmitting a first inverse DQS data signal along the DQS bus.

NAND IO bandwidth increase

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

Techniques for mitigating/eliminating the impact of duty distortion caused by delays in clock paths within a built-in high-frequency test circuit for NAND flash are disclosed. By mitigating or eliminating the impact of duty distortion, accuracy of the valid data window measurement is ensured. Rising edges of a strobe clock signal and an inverted strobe clock signal are used to respectively locate even and odd data (or vice versa) within an input buffer of the NAND flash during respective sweeps of the strobe and inverted strobe clock signals. In this manner, even if the strobe clock signal's duty ratio is distorted, there is no impact on the valid data window measurement. Further, read latency is used to introduce delay to a read enable (RE) clock signal, thereby obviating the need for a replica controlled delay in the RE clock path and eliminating the duty distortion that would otherwise occur.

Built-in high-frequency test circuitry without duty distortion

A command/address sequence associated with a read/write operation for a memory device utilizes various existing command/address clock signals in a novel way that obviates the need to utilize the I/O bus. As such, the command/address sequence can be performed in parallel with the DIN/DOUT operations, thereby removing the performance bottleneck that would otherwise be caused by the command and address sequencing. The command/address sequence encodes bit information on first and second enable signals and utilizes rising or falling edges of a clock signal to latch the encoded bit information, which can then be decoded to determine corresponding command and address codes. A chip select sequence is also disclosed that enables a memory chip configuration to be employed in which each chip in a package shares a common connection to a controller but does not require hard-coded pins for performing chip select.

Chip select, command, and address encoding

Systems and methods disclosed herein provide for selectively activating or deactivating one or more memory of a memory array, such that related data path logic of deactivated memory dies neither detects nor processes control signals or data signals for data operations. Examples of the systems and methods provided herein operate to detect a first enable signal at a memory die and detect a first data signal on input/output (I/O) receivers of the memory die. Responsive to detecting at least the first enable signal, a bit value encoded in the first data signal is latched to obtain a first bit pattern. A second bit pattern is obtained, and, based on a comparison of the first bit pattern to the second bit pattern, the I/O receivers of the memory die are activated.

Methods and systems for selectively enabling/disabling memory dies

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

A non-volatile storage apparatus comprises a non-volatile memory structure and a plurality of I/O pads in communication with the non-volatile memory structure. The I/O pads include a power I/O pad, a ground I/O pad and data/control I/O pads. The non-volatile storage apparatus further comprises one or more capacitors connected to the power I/O pad and the ground I/O pad. The one or more capacitors are positioned in one or more metal interconnect layers below the signal lines and/or above device capacitors on the top surface of the substrate.

Non-volatile memory with capacitors using metal under signal line or above a device capacitor

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

Technology is disclosed herein for a semiconductor die, and controlling operation of the semiconductor die. In some aspects, a semiconductor die is configured to test an I/O circuit on the semiconductor die. The semiconductor die has an input circuit that compares a voltage signal at one of a first input or a second input with a reference voltage at the other of the first input or the second input to generate an input voltage signal. The first input may be connected to an I/O contact. During a normal mode a control circuit on the die provides a reference voltage to second input. During a test mode, the control circuit internally loops back a test signal from an output circuit to the second input of the input circuit. Thus, the test signal avoids the I/O contact.

Input/output circuit internal loopback

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 data storage system includes a storage medium including plurality of memory cells, a storage controller in communication with the storage medium, an electrical interface circuitry configured to pass data via a channel disposed between the storage medium and the storage controller; and voltage training circuitry configured to train a high-level output voltage (VOH) for each of a plurality of data lines of the channel. Training the VOH includes, for each of the plurality of data lines of the channel, calibrating a pull-up driver of the storage controller against an on-die termination circuit of the storage medium, calibrating a pull-down driver of the storage controller against the pull-up driver of the storage controller, and calibrating an on-die termination circuit of the storage controller against a pull-up driver of the storage medium.

High-level output voltage training for non-volatile memory

Circuits and systems for generating counter signals are provided herein. A circuit may comprise a shift register having a series of flip-flops. Each of the flip-flops of the series may be coupled to a clock. The shift register may generate a borrowing clock signal using an output of a flip-flop of the shift register, and a transition of the borrowing clock signal may be advanced by a number of clock cycles based on a position of the flip-flop of the shift register. The circuit may further comprise a clock divider circuit having a number of divide-by-N counters and a number of flip-flops. A divide-by-N counter may be coupled to a flip-flop of the shift register, and a flip-flop of the clock divider circuit may be coupled to one of the divide-by-N counters and to the clock.

Cycle borrowing counter

Growing community of inventors

San Jose, CA, United States of America

Venkatesh Ramachandra