Abstract: The present invention provides for high speed signal buses in printed circuit boards. For high speed operation, each signal line of a bus has substantially the same electrical length as the other signal lines and forms a loop in two halves, each half electrically shielded from the other half. Each signal line has a first and a second terminal, with each terminal connected to a reference bias voltage through a first resistance which matches a loaded characteristic impedance of the signal line. The reference bias voltage is set at a midpoint of signal voltage swings on the signal line. Such high speed buses have particular applications to high speed memory systems with DRAMs.

Abstract: The present invention provides for a method of operation for a memory system having a memory controller integrated circuit, a plurality of memory integrated circuits, particularly DRAMs, and a plurality of signal lines connected to memory controller and the memory integrated circuits. To avoid the problem of the problem of skew between the signals to and from the DRAMs, the method of operation determines a delay between an issued read command and receipt of signals from a selected DRAM by the controller integrated circuit in response to the read command, and sets a read delay in the selected DRAM.