Abstract: In a memory system an interface circuit includes an interface to a memory array, and to a data signal. The circuit includes loopback circuitry to enable loopback of received data signals without having to access the data from the memory array. The circuit can be part of a memory device, a register device, or a data buffer. The circuit interfaces to a memory array of a memory device, and performs loopback functions for a host controller that can test the operation of the interface.

Abstract: Methods and apparatus for duty cycle adjuster optimization training algorithms to minimize jitter associated with DDR5 DRAM transmitters. Basic and Advanced Duty Cycle Adjuster (DCA) training algorithms are implemented to reduce duty cycle error and hence reduce phase mismatch translated jitter in the transmitter DQS signals. In accordance with aspects of the Basic DCA training algorithm, duty cycles for QCLK, IBQCLK, and QBCLK are adjusted by a memory controller that utilizes a DCA function implemented on a memory module (e.g., DDR5 SDRAM DIMM) to obtain a first set of optimized DCA code settings. The first set of optimized DCA code settings are then used as initial settings for the Advance DCA training algorithm to further optimize the DCA code settings for QCLK, IBQCLK, and QBCLK. A similar technical may be employed to reduce duty cycle error and jitter for DQ signals.

Abstract: In a memory system, reference voltage training per path provides the capability to train receiver and transmitter reference voltages to optimal values based on selected feedback per path from the memory device. Training receiver reference voltages to an optimal receiver reference voltage per path includes programming dedicated mode registers that enable a local receiver voltage reference adjuster circuit to adjust the receiver reference voltage per path to the optimal receiver reference voltage per path. Transmitter reference voltage training includes the capability to also train an optimal input timing delay for an optimal transmitter reference voltage. Reference voltage training can be performed by a host component and/or a test system having access to the selected feedback per path of the memory device undergoing training.

Abstract: In a memory system, receiver reference voltage adjustment per path provides the capability to adjust receiver reference voltages on a per path basis. Adjustment of receiver reference voltages for the memory device to an optimal receiver reference voltage per path is accomplished with dedicated mode registers and a local receiver voltage reference adjuster circuit in the memory device for each data path. The optimal receiver reference voltage is determined during training based on selected feedback per path from the memory device. The dedicated mode registers contain adjustment values that were previously programmed during training, and include adjustments steps to add to or subtract from a global receiver reference voltage for all paths until reaching the optimal receiver reference voltage for a current path.

Abstract: A method, apparatus and system. The method includes: performing one or more training iterations to tune a target clock signal frequency to be applied at a memory device, each of the one or more training iterations including: causing a modified clock signal frequency to be applied at the memory device; and decoding a quality feedback message from the memory device including an indication of a performance of the clock signal frequency at the memory device; and in response to a determination that the performance of the clock signal frequency falls within a target performance range of the memory device and that the clock signal frequency is below the target clock signal frequency, performing a subsequent training iteration of the one or more training iterations, and otherwise causing application at the memory device, during a memory operation, of a highest clock signal frequency corresponding to a training iteration for which performance of the clock signal was within the target performance range.

Abstract: In a memory system an interface circuit includes an interface to a memory array, and to a data signal. The circuit includes loopback circuitry to enable loopback of received data signals without having to access the data from the memory array. The circuit can be part of a memory device, a register device, or a data buffer. The circuit interfaces to a memory array of a memory device, and performs loopback functions for a host controller that can test the operation of the interface.

Abstract: In a memory system an interface circuit includes an interface to a memory array, and to a data signal. The circuit includes loopback circuitry to enable loopback of received data signals without having to access the data from the memory array. The circuit can be part of a memory device, a register device, or a data buffer. The circuit interfaces to a memory array of a memory device, and performs loopback functions for a host controller that can test the operation of the interface.

Abstract: An N-bit bus includes (N?1) bidirectional interfaces to couple to (N?1) bidirectional signal lines to exchange (transmit and receive) signals between companion devices. The bus includes two unidirectional signal line interfaces. The first is a unidirectional receive interface to couple to a unidirectional signal line to receive signals from the companion device. The second is a unidirectional transmit interface to couple to a unidirectional signal line to transmit signals to the companion device. The bus provides N signal lines for the N-bit bus in each direction, with an additional “backwards facing” signal line. The backwards facing signal line can allow the devices to prepare for a switch in the direction of the N-bit bus.

Abstract: In a memory system an interface circuit includes an interface to a memory array, and to a data signal. The circuit includes loopback circuitry to enable loopback of received data signals without having to access the data from the memory array. The circuit can be part of a memory device, a register device, or a data buffer. The circuit interfaces to a memory array of a memory device, and performs loopback functions for a host controller that can test the operation of the interface.

Abstract: In a memory system an interface circuit includes an interface to a memory array, and to a data signal. The circuit includes loopback circuitry to enable loopback of received data signals without having to access the data from the memory array. The circuit can be part of a memory device, a register device, or a data buffer. The circuit interfaces to a memory array of a memory device, and performs loopback functions for a host controller that can test the operation of the interface.

Abstract: In a memory system an interface circuit includes an interface to a memory array, and to a data signal. The circuit includes loopback circuitry to enable loopback of received data signals without having to access the data from the memory array. The circuit can be part of a memory device, a register device, or a data buffer. The circuit interfaces to a memory array of a memory device, and performs loopback functions for a host controller that can test the operation of the interface.