Circuits and methods are described for a DDR memory controller where two different DQS gating modes are utilized. These gating modes together ensure that the DQS signal, driven by a DDR memory to the memory controller, is only available when read data is valid. Two types of gating logic are used: Initial DQS gating logic, and Functional DQS gating logic. The Initial gating logic has additional timing margin in the Initial DQS gating value to allow for the unknown round trip timing during initial bit levelling calibration. DQS functional gating is then optimized during further calibration to gate DQS precisely as latency and phase calibration are performed, resulting in a precise gating value for Functional DQS gating. Providing dual gating modes is especially useful when data capture is performed at half the DQS frequency in view of rising clock rates for DDR memories.

A method of communicating with a memory device through a plurality of sub-channels and a control sub-channel includes; setting a first mode or a second mode. In the first mode, writing or reading first data corresponding to a command synchronized to the control sub-channel through the plurality of sub-channels, and in the second mode, independently writing or reading second data and third data respectively corresponding to different commands synchronized to the control sub-channel through the plurality of sub-channels.

A frequency adjustment method, a System-On-a-Chip, and a terminal are provided. In the embodiments of this application, when an access bandwidth requirement on a DDR memory changes, a first frequency adjustment request for a DDR interface is generated using a CPU, and a working frequency of the DDR interface is adjusted. Because during adjustment of the working frequency of the DDR interface, the working frequency of the DDR interface is gradually adjusted according to a predetermined adjustment amount by which a frequency adjustment coefficient of a spread spectrum clocking generator is adjusted each time and a predetermined interval between two adjacent adjustments, it is ensured that a DLL in the DDR interface and a phase-locked loop in the spread spectrum clocking generator are in locking-in states, so that the DDR memory can still be accessed during frequency adjustment of the DDR interface and system performance is ensured.

A memory controller and buffers on memory modules each operate in two modes, depending on the type of motherboard through which the controller and modules are connected. In a first mode, the controller transmits decoded chip-select signals independently to each module, and the motherboard data channel uses multi-drop connections to each module. In a second mode, the motherboard has point-to-point data channel and command address connections to each of the memory modules, and the controller transmits a fully encoded chip-select signal group to each module. The buffers operate modally to correctly select ranks or partial ranks of memory devices on one or more modules for each transaction, depending on the mode.

An interface is provided comprising: a receptacle arranged to receive a memory device; and a detection signal line arranged to transmit an electrical signal identifying a type of the memory device.

Memory devices, systems, and methods that maximize command and address (CA) signal group rate with minimized margin degradation across a channel and associated operating modes are disclosed and described. In one example, the operating mode can be 1 bit per 1.5 clock cycles.

The timing of the synchronous interface is controlled by a clock signal driven by a controller. The clock is toggled in order to send a command to a memory device via the interface. If there are no additional commands to be sent via the interface, the controller suspends the clock signal. When the memory device is ready, the memory device drives a signal back to the controller. The timing of this signal is not dependent upon the clock signal. Receipt of this signal by the controller indicates that the memory device is ready and the clock signal should be resumed so that a status of the command can be returned via the interface, or another command issued via the interface.

A memory access mode detection circuit and method for detecting and initiating memory access modes for a memory device The memory access mode detection circuit receives the memory address signals, the control signals, and the clock signal and generates a first mode detection signal in response to receipt of the memory address signals or a first combination of control signals. An first mode initiation signal is generated a time delay subsequent to the detection signal to initiate the first mode memory access operation. In response to receipt of a second combination of control signals and an active clock signal, the memory access mode detection circuit further generates a second mode detection signal to initiate a second mode memory access operation and to suppress generation of the first mode detection signal, thereby canceling the first mode memory access operation.

A buffer manager is generated by executing a script with respect to a buffer architecture template and a configuration file specifying parameters for the buffer such as, for example, number of memory banks, width of memory banks, depth of memory banks, and client bridge FIFO depth. The script converts the buffer architecture template into a hardware description language (HDL) description of a buffer manager having the parameters. Client bridges accumulate requests for memory banks in FIFO that is provided to a buffer manager upon the client bridge being granted arbitration. Accesses of memory banks may be performed one at a time in consecutive clock cycles in a pipelined manner. Client bridges and the buffer manager may operate in different clock domains. The clock frequency of the buffer manager may be increased or decreased according to requests from client devices.

A portable lighting device that provides different user interfaces that may be selected by the user. Each user interface may provide one or more operational modes, such as on mode, power save mode, strobe mode or momentary mode. After a user interface is selected, the user may select on of the operational modes. The portable lighting device may be a flashlight.