Memory devices and a memory controller that controls such memory devices. Multiple memory devices receive commands and addresses on a command/address (C/A) bus that is relayed point-to-point by each memory device. Data is received and sent from these devices to/from a memory controller in a point-to-point configuration by adjusting the width of each individual data bus coupled between the individual memory devices and the memory controller. Along with the C/A bus are clock signals that are regenerated by each memory device and relayed. The memory controller and memory devices may be packaged on a single substrate using package-on-package technology. Using package-on-package technology allows the relayed C/A signals to connect from memory device to memory device using wire bonding. Wirebond connections provide a short, high-performance signaling environment for the chip-to-chip relaying of the C/A signals and clocks from one memory device to the next in the daisy-chain.

A node in a daisy chain includes a serial data input port configured to receive input from an electronic device, a serial data output port configured to send output to another electronic device, a chip select input port configured to receive input from a master control unit, a timer, and an interface circuit. The interface circuit may be configured to, in a daisy chain mode, copy data received at the serial data input port to the serial data output port, and upon receipt of a changed edge of a chip select signal on the chip select input port, initiate the timer. The interface circuit may be configured to, upon the completion of a time to be determined by the timer, enter the daisy chain mode.

A computing system includes a host, a first electronic device connected to the host, and a second electronic device that communicates with the host through the first electronic device. The first electronic device requests a command written in a submission queue of the host based on a doorbell transmitted from the host, stores the command transmitted from the host, requests write data stored in a data buffer of the host, and stores the write data of the data buffer transmitted from the host.

A memory system of a high-speed operation can be realized by reducing an influence of reflection signals etc. caused by branching and impedance mismatching in various wirings between a memory controller and a memory module, and an influence due to transmission delays of data, command/address, and clocks in the memory module. To this end, a memory system comprises a memory controller and a memory module mounted with DRAMs. A buffer is mounted on the memory module. The buffer and the memory controller are connected to each other via data wiring, command/address wiring, and clock wiring. The DRAMs and the buffer on the memory module are connected to each other via internal data wiring, internal command/address wiring, and internal cock wiring. The data wiring, the command/address wiring, and the clock wiring may be connected to buffers of other memory modules in cascade. Between the DRAMs and the buffer on the memory module, high-speed data transmission is implemented using data phase signals synchronous with clocks.

A device for controlling a transfer of information from a plurality of electronic components through a communication bus to a host device, comprising a chain of processing blocks connected to the electronic components, each of the processing blocks associated with one, or a set, of the electronic components, which processing blocks are arranged such that during the transfer of information an authorization signal propagates through the chain of processing blocks and, when the authorization signal encounters a processing block associated with one of the electronic components or one of the sets of electronic components which contains an information value to be transferred, effecting the transfer of the information value through the communication bus to the host device. The processing blocks are arranged to coordinate their processing in accordance with a clock signal generated independent of a propagation status of the authorization signal within the chain of processing blocks.

A computing system includes a host, a first electronic device connected to the host, and a second electronic device that communicates with the host through the first electronic device. The first electronic device requests a command written in a submission queue of the host based on a doorbell transmitted from the host, stores the command transmitted from the host, requests write data stored in a data buffer of the host, and stores the write data of the data buffer transmitted from the host.

A memory system of a high-speed operation can be realized by reducing an influence of reflection signals etc. caused by branching and impedance mismatching in various wirings between a memory controller and a memory module, and an influence due to transmission delays of data, command/address, and clocks in the memory module. To this end, a memory system comprises a memory controller and a memory module mounted with DRAMs. A buffer is mounted on the memory module. The buffer and the memory controller are connected to each other via data wiring, command/address wiring, and clock wiring. The DRAMs and the buffer on the memory module are connected to each other via internal data wiring, internal command/address wiring, and internal cock wiring. The data wiring, the command/address wiring, and the clock wiring may be connected to buffers of other memory modules in cascade. Between the DRAMs and the buffer on the memory module, high-speed data transmission is implemented using data phase signals synchronous with clocks.

A method for operating a data interface circuit whereby calibration adjustments for data bit capture are made without disturbing normal system operation includes initially establishing, using a first calibration method where a data bit pattern received by the data interface circuit is predictable, an optimal sampling point for sampling data bits received by the data interface circuit, and during a normal system operation and without disturbing the normal system operation, performing a second calibration method where the data bit pattern received by the data interface circuit is unpredictable. The second calibration method determines an amount of a timing drift for received data bit edge transitions and adjusts the optimal timing point determined by the first calibration method to create a revised optimal timing point. The second calibration method samples fringe timing points associated with the transition edges of a data bit.

An apparatus may include a serial data output port configured to send output data to a electronic device. The apparatus may include a serial data input port configured to receive input data from another electronic device. The apparatus may include a chip select output port configured to send output to the electronic devices connected in a daisy chain. The apparatus may include a interface circuit, configured to determine that a given electronic device is to selectively execute a first command. The interface circuit may be further configured to issue a complex command to the electronic devices connected. The complex command may indicate to the f electronic devices that additional commands are to be selectively executed.

Devices in an array of devices, coupled to a common SPI bus, are automatically assigned identifiers by an enumeration process. In some embodiments, the devices are coupled together in an enumeration daisy chain. The enumeration function is initiated, e.g., by a controller, with a single SPI transaction.