Abstract: A semiconductor memory module includes a memory printed circuit board (PCB) that includes first connectors, a second connector, and a third connector configured to be connectable with an external device, memory devices that are mounted on the memory PCB and are connected with the first connectors, and a power management integrated circuit that is mounted on the memory PCB, receives a first voltage through the second connector, generates a second voltage from the first voltage, and supplies the second voltage to the memory devices. The power management integrated circuit adjusts the second voltage depending on a difference between a signal received through the third connector and the second voltage.

Abstract: A memory module includes semiconductor memory devices mounted on a circuit board and a control device mounted on the circuit board. The control device receives a command, an address, and a clock signal from an external device, and provides the command, the address, and the clock signal to the semiconductor memory devices. The control device, in a hidden training mode during a normal operation, performs a command/address training on at least one semiconductor memory device of the semiconductor memory devices by transmitting a first command/address and a first clock signal to the at least one semiconductor memory device and receiving a second command/address and a second clock signal in response to the first command/address and the first clock signal, from the at least one semiconductor memory device.

Abstract: A semiconductor memory module includes a memory printed circuit board (PCB) that includes first connectors, a second connector, and a third connector configured to be connectable with an external device, memory devices that are mounted on the memory PCB and are connected with the first connectors, and a power management integrated circuit that is mounted on the memory PCB, receives a first voltage through the second connector, generates a second voltage from the first voltage, and supplies the second voltage to the memory devices. The power management integrated circuit adjusts the second voltage depending on a difference between a signal received through the third connector and the second voltage.

Abstract: A memory module includes semiconductor memory devices mounted on a circuit board and a control device mounted on the circuit board. The control device receives a command, an address, and a clock signal from an external device, and provides the command, the address, and the clock signal to the semiconductor memory devices. The control device, in a hidden training mode during a normal operation, performs a command/address training on at least one semiconductor memory device of the semiconductor memory devices by transmitting a first command/address and a first clock signal to the at least one semiconductor memory device and receiving a second command/address and a second clock signal in response to the first command/address and the first clock signal, from the at least one semiconductor memory device.