Abstract: A memory controller for controlling a daisy chain of self timed memory chips. The memory controller has information as to how long each self timed memory chip in the daisy chain of memory chips takes to make a read access and a write access to an array on the self timed memory chip. The memory controller determines current access time information on a memory chip by sending a command to the memory chip. The memory chip returns a data word containing the current access time information. Alternatively, the memory controller transmits an address/command word to the memory chip and, after completing an access, transmits a responsive data word to the memory controller. The memory controller determines the access time information using the interval from transmission of the address/command word to reception of the responsive data word.

Abstract: A method and structure are provided for implementing component placement suspended within electrical pin grid array packages for enhanced electrical performance. A solder column grid array is coupled between a printed circuit board and a first level package. A component is connected between a predefined pair of adjacent columns in the solder column grid array suspended between the printed circuit board and the first level package.

Abstract: A self timed memory chip having an apportionable data bus. Access timing to an array on the memory chip is dynamically determined by circuitry on the memory chip. A ring oscillator on the memory chip has a frequency that is indicative of how fast an array on the memory chip can be accessed. The ring oscillator includes a bit line that is periodically charged and a memory element that subsequently discharges the bit line. The memory chip has a data bus interface having a number of bits. The data bus interface has a first number of bits apportioned to write data and a second number of bits apportioned to read data. The first number of bits and the second number of bits is programmable.

Abstract: A memory system having a memory controller and a memory. The memory comprises one or more daisy chains of self timed memory chips. An address/command word is chained through a daisy chain of memory chips and is handled by one of the memory chips in the daisy chain of memory chips. Data to be written to a memory chip is sent as part of the address/command word, or is transferred on an outgoing data bus chain. Data read from a memory chip is transferred on an incoming data bus chain. Access timing on a memory chip is determined by a self time block on the memory chip.

Abstract: Structures and a computer program product are provided for implementing enhanced wiring capability for electronic laminate packages. Electronic package physical design data are received. Instances of line width and space limit violations in the electronic package physical design data are identified. The identified instances of line width and space limit violations are evaluated using predefined qualified options and tolerance limitations and the electronic package physical design data are modified to optimize shapes to replace the instances of line width and space limit violations.

Abstract: A memory controller provides page copy logic that assures data coherency when a DMA operation to a page occurs during the copying of the page by the memory controller. The page copy logic compares the page index of the DMA operation to a copy address pointer that indicates the location currently being copied. If the page index of the DMA operation is less than the copy address pointer, the portion of the page that would be written to by the DMA operation has already been copied, so the DMA operation is performed to the physical address of the new page. If the page index of the DMA operation is greater than the copy address pointer, the portion of the page that would be written to by the DMA operation has not yet been copied, so the DMA operation is performed to the physical address of the old page.

Abstract: Multiple interfaces dedicated to individual logic circuits such as memory arrays are capable of being dynamically reconfigured from operating separately and in parallel to operating in a more collective manner to ensure that data associated with all of the logic circuits will be communicated irrespective of a failure in any of the interfaces. Specifically, a plurality of interfaces, each of which being ordinarily configured to communicate data associated with an associated logic circuit in parallel with the other interfaces, may be dynamically reconfigured, e.g., in response to a detected failure in one or more of the interfaces, to communicate data associated with each of the interfaces over each of at least a subset of the interfaces in a time multiplexed and replicated manner.

Abstract: A memory system having a memory controller and a daisy chain of memory chips. The memory controller is coupled to memory chips in the daisy chain of memory chips by an address/command bus chain. The memory controller is coupled to memory chips in the daisy chain of memory chips by a data bus chain having a number of data bus bits. The data bus chain has a first portion of data bus bits dedicated to transmitting write data from the memory controller to a memory chip. The data bus chain has a second portion of data bus bits dedicated to transmitting read data from a memory chip to the memory controller. Apportionment of data bus bits between the first portion and the second portion is programmable. Programming is done by pin connection, scanning of a value, or by request from a processor coupled to the memory controller.

Abstract: A memory chip suitable for use in a daisy chain of memory chips. The memory chip receives an address/command word on a first input, determines if the address command word is directed to the memory chip; if so, the memory chip accesses an array on the memory chip. If not, the memory chip re-drives the address/command word on a first output. Write data is received as part of the address/command word or from a first data bus port. A bus clock is received and is used to receive and transmit information on the first input, the first output, the first data bus port and the second data bus port. The memory chip is incorporated into a design structure that is embodied in a computer readable medium used for designing, manufacturing, or testing the memory chip.

Abstract: A memory module contains a first interface for receiving data access commands and a second interface for re-transmitting data access commands to other memory modules, the second interface propagating multiple copies of received data access commands to multiple other memory modules. The memory module is preferably used in a high-capacity memory subsystem organized in a tree configuration in which data accesses are interleaved.

Abstract: A dual-mode memory chip supports a first operation mode in which received data access commands contain chip select data to identify the chip addressed by the command, and control logic in the memory chip determines whether the command is addressed to the chip, and a second operation mode in which the received data access command addresses a set of multiple chips. Preferably, the first mode supports a daisy-chained configuration of memory chips. Preferably the second mode supports a hierarchical interleaved memory subsystem, in which each addressable set of chips is configured as a tree, command and write data being propagated down the tree, the number of chips increasing at each succeeding level of the tree.

Abstract: A high-capacity memory subsystem architecture utilizes multiple memory modules arranged in a hierarchical tree configuration, in which at least some communications from an external source traverse successive levels of the tree to reach memory modules at the lowest level.

Abstract: A memory module contains an interface for receiving memory access commands from an external source, in which a first portion of the interface receives memory access data at a first bus frequency and a second portion of the interface receives memory access data at a second different bus frequency. Preferably, the memory module contains a second interface for re-transmitting memory access data, also operating at dual frequency. The memory module is preferably used in a high-capacity memory subsystem organized in a tree configuration in which data accesses are interleaved. Preferably, the memory module has multiple-mode operation, one of which supports dual-speed buses for receiving and re-transmitting different parts of data access commands, and another of which supports conventional daisy-chaining.

Abstract: A high-capacity memory subsystem architecture utilizes multiple memory modules arranged in one or more clusters, each attached to a respective hub which in turn is attached to a memory controller. Within a cluster, data is interleaved so that each data access command accesses all modules of the cluster. The hub communicates with the memory modules at a lower bus frequency, but the distributing of data among multiple modules enables the cluster to maintain the composite data rate of the memory-controller-to-hub bus.

Abstract: A high-capacity memory subsystem architecture utilizes multiple memory modules coupled to one or more access modules by a communications medium, in which at least some data is transferred between an access module and memory modules at a first bus frequency, and at least some data is transferred between the access module and memory modules at a second bus frequency different from the first. Preferably, data is interleaved to reduce the required bus speed for read/write data, and the higher bus frequency is used to transfer command/address data. Preferably, the memory system employs memory chips having dual-mode operation, one of which supports a dual-speed bus.

Abstract: A high-capacity memory subsystem architecture utilizes multiple memory modules arranged in one or more clusters, each attached to a respective hub which in turn is attached to a memory controller. Within a cluster, data is interleaved so that each data access command accesses all modules of the cluster. The hub communicates with the memory modules at a lower bus frequency, but the distributing of data among multiple modules enables the cluster to maintain the composite data rate of the memory-controller-to-hub bus.

Abstract: A method is provided for implementing vertically coupled noise control through a mesh plane in an electronic package design. Electronic package physical design data are received. Instances of vertically coupled noise in the electronic package physical design data are identified. The identified instances of vertically coupled noise are quantified. Then the electronic package physical design data are modified to limit the vertically coupled noise.

Abstract: A method is provided for implementing enhanced wiring capability for electronic laminate packages. Electronic package physical design data are received. Instances of line width and space limit violations in the electronic package physical design data are identified. The identified instances of line width and space limit violations are evaluated using predefined qualified options and tolerance limitations and the electronic package physical design data are modified to optimize shapes to replace the instances of line width and space limit violations.

Abstract: Multiple interfaces dedicated to individual logic circuits such as memory arrays are capable of being dynamically reconfigured from operating separately and in parallel to operating in a more collective manner to ensure that data associated with all of the logic circuits will be communicated irrespective of a failure in any of the interfaces. Specifically, a plurality of interfaces, each of which being ordinarily configured to communicate data associated with an associated logic circuit in parallel with the other interfaces, may be dynamically reconfigured, e.g., in response to a detected failure in one or more of the interfaces, to communicate data associated with each of the interfaces over each of at least a subset of the interfaces in a time multiplexed and replicated manner.

Abstract: A method and apparatus implement redundant memory access using multiple controllers on the same bank of memory. A first memory controller uses the memory as its primary address space, for storage and fetches. A second redundant controller is also connected to the same memory. System control logic is used to notify the redundant controller of the need to take over the memory interface. The redundant controller initializes if required and takes control of the memory. The memory only needs to be initialized if the system has to be brought down and restarted in the redundant mode. This invention allows the system to continue to stay up and continue running during a memory controller or link failure.