Abstract: A method and an associated system and computer program product for determining sequences suitable for testing an electronic system that is comprised of a set of nets. Each net of the system provides an interconnect between a set of nodes. The method includes a step in which nodes that are enabled by a common enable latch within the system are identified. Each commonly enabled node is associated with a node group. Each node group includes the set of nodes that share a common enable latch. Contending node group pairs within the system are then identified. A contending node group pair is any pair of node groups in which at least one commonly enabled node of the first node group and at least one node of the second node group reside on a common net. Sequence numbers, preferably for use in defining a boundary scan test sequence, are then assigned to each commonly enabled node in the system.

Abstract: A floating point to fixed point converter suitable for determining values for an n-bit frame buffer of a graphics adapter is disclosed. The converter includes a floating point unit that receives a floating point input value and calculates a floating point adjusted input value from the received value. Comparator circuitry is configured to compare a fixed point portion of the adjusted input value to a fixed point comparison value and to generate a fixed point output value responsive to the result of the comparison. The floating point unit may add a floating point constant to the received input to calculate the adjusted input value. The floating point constant may include a rounding component and a range component. The range component adjusts received values into a range defined by a single floating point exponent value such as the range from 1.0 to 2.0.

Abstract: A method, system and program for controlling access to memory areas within a computer are provided. The invention comprises placing a first Bind Work Queue Element (WQE) at the head of a work queue, wherein the first Bind WQE defines parameters associated with a first Memory Window. A set of Work Requests is then placed on the work queue, behind the first Bind WQE wherein the work requests invoke operations that access the first Memory Window. A second Bind WQE is then placed on the work queue, behind the first set of Work Requests. This second Bind WQE defines parameters associated with a second Memory Window. A second set of Work Requests is placed on the work queue behind the second Bind WQE and invoke operations that access the second memory window. The Memory Windows can be associated with a common Memory Region and have different addresses and lengths or different access rights. In another embodiment, the first and second Memory Windows can be associated with different Memory Regions.

Abstract: A system for controllable run-time verification of operations in a logic structure of a digital system. The system comprises a controllable bit stream generator which produces a controlled bit stream output. The controlled bit stream output corresponds to a bit sequence which instantiates a verification of operations within the logic structure. The system also comprises means for coupling the controlled bit stream output to the logic structure to verify the operations of the logic structure.

Abstract: A distributed system structure for a large-way, symmetric multiprocessor system using a bus-based cache-coherence protocol is provided. The distributed system structure contains an address switch, multiple memory subsystems, and multiple master devices, either processors, I/O agents, or coherent memory adapters, organized into a set of nodes supported by a node controller. The node controller receives commands from a master device, communicates with a master device as another master device or as a slave device, and queues commands received from a master device. The node controller has a deterministic delay between latching a snooped command broadcast by the address switch and presenting the command to the master devices on the node controller's master device buses.

Abstract: A method in a data processing system for identifying a circuit. In a preferred embodiment, a set of bits, with a defined chain length, are shifted into the circuit one bit at a time. The bits shifted out from the circuit are compared to the bits, from the set of bits, shifted into the circuit to determine if the circuit corresponds to a first type circuit. The comparing step is accomplished before all bits in the set of bits have been shifted into the circuit. If the circuit is not a first type circuit corresponding to the set of bits shifted into the circuit, then the shifting of bits into the circuit is discontinued and the process is repeated with a second set of bits corresponding to a second circuit type until the circuit type has been identified.

Abstract: A PCI host bridge and an associated method of use are disclosed. The PCI host bridge includes a host bus interface, an I/O bus interface, and a PCI operation detection circuit. The host bus interface is suitable for communicating with a host bus of a data processing system and the I/O bus interface is suitable for communicating with a primary PCI bus operating in PCI-X mode. The PCI operation detection circuit is adapted to detect a PCI-X operation from the primary PCI bus that may have issued from a PCI mode adapter coupled to a secondary PCI bus. The detection circuit is further adapted to generate a modified operation for forwarding to the host bus in response to determining that the PCI-X operation may have originated from a PCI. mode adapter.

Abstract: A system and method for optimally processing split request transactions across a PCI-X bridge with a PCI-X bridge buffer. The split transaction mode of the PCI-X bridge buffer is toggled between a No Over-commit mode and an over-commit mode. Over-commitment of the buffer is inhibited when the split transaction mode is toggled to the No Over-commit mode and when the buffer is over committed by the bridge. At least some over-commitment of the buffer is allowed by the bridge when the split transaction mode is toggled to the over-commit mode and when the buffer is not over committed by the bridge. The over-commit mode may be an Over-commitment mode or a Flood mode. The Over-commitment mode allows some degree of over commitment of the buffer by the bridge while the Flood mode allows the bridge to forward all split request transactions regardless of size of the transactions or amount of available space in the buffer when the Over-commit mode is in a Flood mode.

Abstract: A method, system and program for controlling access to computer memory are provided. The present invention comprises receiving a work request from a user, wherein the work request comprises an index portion and a protection portion. The index portion of the work request is used to locate an element in an address translation and protection table. The protection portion of the work request is then compared with a protection key in the table element, and access to memory is granted only if the protection portion and protection key match.

Abstract: A system, device, and method for dynamically testing integrated circuits is disclosed. The system includes a first integrated circuit including input pins, output pins, normal operating logic, and control logic. The control logic is connectable to the input pins and configured to initiate a test interval based on a state of the input pins and to record the state of the input pins during the test interval. A second integrated circuit of the system includes input pins, output pins, normal operating logic, and test control logic. The control logic connectable to the output pins and configured to generate a user programmable set of test output signals. At least some of the output pins of the second integrated circuit are connected to at least some of the input pins of the first integrated circuit. The test control logic of the first integrated may be configured to initiate the test interval when the state of the input pins matches a predefined state.

Abstract: An apparatus and method for providing a transient connection port are provided. Further, an apparatus and method for switching between a permanent connection port and a transient connection port are provided. The apparatus and method include a permanent connection port and a transient connection port located at the rear of a rack mounted server system and the front of the rack mounted server system, respectively. The permanent connection port operates when there is an absence of a connected device at the transient connection port. When a device is connected to the transient connection port, a signal is sent to a logic switch which causes the active input to be switched from the permanent connection port to the transient connection port. When the device is no longer connected to the transient connection port, the absence of the signal from the transient connection port causes the logic switch to switch the active input back to the permanent connection port.

Abstract: A method and apparatus for selecting an instruction to be monitored within a pipelined processor in a data processing system is presented. A plurality of instructions are fetched, and the plurality of instructions are matched against at least one match condition to generate instructions that are eligible for sampling. The match conditions may include matching the opcode of an instruction, the pre-decode bits of an instruction, a type of instruction, or other conditions. The matched instructions may be marked using a match bit that accompanies the instruction through the selection process. The instructions eligible for sampling are then sampled to generate a sampled instruction. A sampled instruction may be marked with a sample bit that accompanies the instruction through the instruction execution process in order to monitor the sampled instruction while it is executing within the pipelined processor.

Abstract: A method, system and computer program are described for isolating bus errors detected during system start-up by utilizing a technique in which a shared mailbox associated with a service processor is provided for holding the address of an adapter in an I/O drawer. If an error is detected the server processor is notified. The server processor then retrieves the address from the mailbox, uses it to derive a location code which is then passed along with the error code to an appropriate error analysis routine. The start-up procedure is then shut down.

Abstract: One embodiment of an electrical contact has a copper alloy substrate and a hard underlayer plating such as nickel. The underlayer is coated with a thin, liquid barrier film coating. The substance that forms the coating is one of the proprietary materials that are described in military specifications MIL-C-81309E, and MIL-L-87177A, Amendment 1. The military specifications generally describe classes of ultra-thin film, water-displacing, corrosion preventive compounds that may be applied by dipping, brushing, or from gas-pressurized containers. The mating surfaces of both mating contacts (i.e., male and female) are provided with the coating. The coatings provide excellent corrosion protection for both contacts despite physical contact therebetween.

Abstract: A method and apparatus in a data processing system for updating a buffer containing display information used to display pixels from a first layer and a second layer on a display in the data processing system. Display information is identified for pixels in the first layer in a region corresponding to a removal of pixels being displayed in the second layer. This identification is performed using a data structure containing display information for displaying pixels in the first layer and pixels in the second layer to form identified display information. Display information in the buffer is updated using identified display information.

Abstract: A method and apparatus are disclosed for communicating between a master and slave device. A sequence of data sets and a clock signal (“Bus clock”) are sent from the master to the slave, wherein the successive sets are asserted by the master at a certain frequency, each set being asserted for a certain time interval. The data and Bus clock are received by the slave, including capturing the data by the slave, responsive to the received Bus clock. The slave generates, from the received Bus clock, a clock (“Local clock”) for clocking operations on the slave. The sequence of the received data sets is held in a sequence of latches in the slave, each set being held for a time interval that is longer than the certain time interval for which the set was asserted by the master.

Abstract: A method, system, and computer program product for enforcing logical partitioning of a shared device to which multiple partitions within a data processing system have access is provided. In one embodiment, a firmware portion of the data processing system receives a request from a requesting device, such as a processor assigned to one of a plurality of partitions within the data processing system, to access (i.e., read from or write to) a portion of the shared device, such as an NVRAM. The request includes a virtual address corresponding to the portion of the shared device for which access is desired. If the virtual address is within a range of addresses for which the requesting device is authorized to access, the firmware provides access to the requested portion of the shared device to the requesting device. If the virtual address is not within a range of addresses for which the requesting device is authorized to access, the firmware denies the request.

Abstract: An apparatus performs a process for partitioning a netlist. The process picks a unique color for each clock and traverses the clock tree coloring the latches in support of that clock tree with that color. The process then colors the fanout logic cones for each latch and notes any coloring collisions. In the case of a multicolored gate, the process retimes the network by moving the terminating latch backwards, towards the collision, to enable single coloring of the gate. The process then performs a depth-first search on the fanout logic of each primary input to the first latch encountered or a primary output. If a primary output is encountered, the path is colored with a color representing the free-run domain. Otherwise, the process colors the path with the color of the terminating latch. Next, the process duplicates the fanin cones for remaining multicolored gates so that a copy of the logic can be incorporated with each independent domain.

Abstract: A method and apparatus in a data processing system for anti-aliasing an image. The image is rendered to an off screen memory using a size that is larger than a desired size for the image. In the depicted examples, the size is at least two times the desired size. The image is resized within a hardware graphics engine in the data processing system, to the desired size. The image is displayed in the desired size.

Abstract: A coverage analysis process and apparatus assigns a unique label for every unique cycle of data produced by simulation or testing. The labels are substituted for the signal evaluations producing a graph of labels over time. The coverage analysis then generates a function, which represents the graph and the function is stored. The functions are analyzed and compared to determine coverage information. The coverage analysis process and apparatus provides significant data compression and represents the coverage in a form, which can easily be analyzed and compared.