Nvidia Corporation

Ati Technologies Ulc

Robert Bloemer

Gautam Bhatia

Stephen L Morein

Sunil Rao Sudhakaran

Ish Chadha

Various embodiments include a memory device that is capable of performing write training operations. Prior approaches for write training involve storing a long data pattern into the memory followed by reading the long data pattern to determine whether the data was written to memory correctly. Instead, the disclosed memory device stores a first data pattern (e.g., in a FIFO memory within the memory device) or generates the first data pattern (e.g., using PRBS) that is compared with a second data pattern being transmitted to the memory device by an external memory controller. If data patterns match, then the memory device stores a pass status in a register, otherwise a fail status is stored in the register. The memory controller reads the register to determine whether the write training passed or failed.

Techniques for performing write training on a dynamic random-access memory

Various embodiments include a memory device that is capable of transferring both commands and data via a single clock signal input. In order to initialize the memory device to receive commands, a memory controller transmits a synchronization command to the memory device. The synchronization command establishes command start points that identify the beginning clock cycle of a command that is transferred to the memory device over multiple clock cycles. Thereafter, the memory controller transmits subsequent commands to the memory device according to a predetermined command length. The predetermined command length is based on the number of clock cycles needed to transfer each command to the memory device. Adjacent command start points are separated from one another by the predetermined command length. In this manner, the memory device avoids the need for a second lower speed clock signal for transferring commands to the memory device.

Techniques for transferring commands to a dynamic random-access memory

First symbols are generated on a plurality of data channels by applying PAM-N encoding on a first subset of bits of a data burst, the first symbols generated without maximum transitions; second symbols are generated on at least one optionally-activated additional data channel, the second symbols generated by applying the PAM-N encoding on a second subset of bits of the data burst, the second symbols generated without maximum transitions; and third symbols are generated on a channel for communicating error correction bits for the first bits and second bits, the third symbols generated by applying hybrid PAM-N encoding on the error correction bits and a third subset of bits of the data burst, the hybrid PAM-N encoding comprising an interleaving of symbols with N voltage levels and symbols with less than N voltage levels.

Error detection pin encoding scheme to avoid maximum transitions and further improve signal integrity on high speed graphic memory interfaces

Various embodiments include a memory device that is capable of performing command address interface training operations, to determine that certain timing conditions are met, with fewer I/O pins relative to prior approaches. Prior approaches for command address interface training involve loading data via a set of input pins, a clock signal, and a clock enable signal that identifies when the input pins should be sampled. Instead, the disclosed memory device generates a data pattern within the memory device that matches the data pattern continuously being transmitted to the memory device by an external memory controller. The memory device compares the generated data pattern with the received data pattern and transmits the result of the comparison on one or more data output pins. The memory controller receives and analyzes the result of the comparison to determine whether the command address interface training passed or failed.

Techniques for performing command address in interface training on a dynamic random-access memory

Various embodiments include a memory device that is capable of performing write training operations, to determine that certain timing conditions are met, without storing data patterns in memory. Prior approaches for write training involve storing a long data pattern into the memory followed by reading the long data pattern to determine whether the data was written to memory correctly. Instead, the disclosed memory device generates a data pattern within the memory device that matches the data pattern being transmitted to the memory device by an external memory controller. If the data pattern generated by the memory device matches the data pattern received from the memory controller, then the memory device stores a pass status in a register. If the data patterns do not match, then the memory device stores a pass status in a register. The memory controller reads the register to determine whether the write training passed or failed.

Various embodiments include a memory device that recovers from write errors and read errors more quickly relative to prior memory devices. Certain patterns of write data and read data may result on poor signal quality on the memory interface between memory controllers and memory devices. The disclosed memory device, synchronously with the memory controller, scrambles read data before transmitting the data to the memory controller and descrambles received from the memory controller. The scrambling and descrambling results in a different pattern on the memory interface even for the same read data or write data. Therefore, when a write operation or a read operation fails, and the operation is replayed, the pattern transmitted on the memory interface is different when the operation is replayed. As a result, the memory device more easily recovers from data patterns that cause poor signal quality on the memory interface.

Techniques for data scrambling on a memory interface

A microelectronic package has an IC chip that includes logical circuitry for routing certain I/O signals to debug ports disposed on an outer surface of the microelectronic package. The I/O signals include data and command signals that are transmitted between semiconductor chips in the microelectronic package via conductive traces that are not physically accessible via with conventional debugging techniques. The logical circuitry may be configured to programmably select I/O signals based on a software input, and may be connected to the various I/O signals transmitted between the IC chip and another IC chip in the microelectronic package when a debugging of the I/O signals is enabled. Circuitry employed in conventional operation of the IC chip may also be employed to connect the logical circuitry to the various I/O signals.

Multi-chip package with selection logic and debug ports for testing inter-chip communications

A method and apparatus for data transfer includes receiving a first data packet across a first bi-directional bus and receiving a second data packet across a second bi-directional bus. Next, the first data packet is written to a first register operably coupled to the first bi-directional bus and the second bi-directional bus. The second data packet is written to a second register operably coupled to the first bi-directional bus and the second bi-directional bus. The second data packet is then transferred across the first bi-directional bus and the first data packet is transferred across the second bi-directional bus, thereby providing data transfer across a plurality of bi-directional buses and providing for data to be transferred across those buses to be stored at an intermediate register so that the data may be transferred in the next clock cycle, overcoming any latency requirements.

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Sterling, MA, United States of America

Robert Bloemer