Abstract:
A computer system has a central processing unit and a bus. A first bus device and a second bus device are connected to the bus. A circuit is connected to configure the second bus device to be addressable by the central processing unit via the bus only by interaction with the first bus device. The first bus device may be an I 2 O processor, and the second bus device may be an I 2 O subordinate bus device.
Abstract:
A computer system includes a first device on the first data bus, a second device on the second data bus, and a bridge device that delivers requests for data from the first device to the second device and returns the requested data to the first device. The bridge device includes a first data storage buffer that stores data requested by the first device during the first request, and a second data buffer that simultaneously stores data requested by the first device during a second request.
Abstract:
A memory controller (62) provides a stretch signal to a bus controller (48) which develops the synchronizing signal (BGLK) used on a synchronized bus (46), alleviating the need to insert a full wait state during memory read operations. The memory (58) is located off a second bus (44) which is tightly coupled to the processor (20), but devices operating according to the protocol of the synchronized bus can access the memory. The memory controller (62) controls the buffers and address multiplexing between the second bus and the memory devices, while the bus controller (48) controls the buffering and latching between the first and second buses. The memory controller also develops the row and column address strobes used by the memory devices.
Abstract:
Control is switched from a first server to a second server in a fault tolerant system. The first and second servers are coupled with an expansion bus in an expansion box for communication with the expansion bus. An indication is provided to the second server to indicate the activity state of the first server. Communication between the first server and the expansion box is disabled if the indication indicates the first server is inactive. Communication between the second server and the expansion bus is disabled if the indication indicates that the first server is active. Communication between the second server is enabled if the indication indicates that the first server is inactive. The indication includes a heartbeat message transmitted periodically to the second server. The expansion bus includes a PCI bus.
Abstract:
A method and apparatus for enabling a computer user to implement intelligent input/output processing involves a connector adapted to receive interrupt request signals from input/output devices in a plurality of slots contained on an input/output bus. When an intelligent input/output card is inserted into the connector, the card can process certain of the interrupt requests from devices contained in slots connected to the input/output bus. This augments the processing of input/output device interrupt requests without burdening the host processor. Thus, a computer system arranged in a peer architecture may be subsequently enhanced with a intelligent input/output card, without burdening all purchasers with the cost of expensive hardware to enable the subsequent upgrade.
Abstract:
A method and apparatus for enabling a computer user to implement intelligent input/output processing involves a connector adapted to receive interrupt request signals from input/output devices in a plurality of slots contained on an input/output bus. When an intelligent input/output card is inserted into the connector, the card can process certain of the interrupt requests from devices contained in slots connected to the input/output bus. This augments the processing of input/output device interrupt requests without burdening the host processor. Thus, a computer system arranged in a peer architecture may be subsequently enhanced with a intelligent input/output card, without burdening all purchasers with the cost of expensive hardware to enable the subsequent upgrade.
Abstract:
Control is switched from a first server to a second server in a fault tolerant system. The first and second servers are coupled with an expansion bus in an expansion box for communication with the expansion bus. An indication is provided to the second server to indicate the activity state of the first server. Communication between the first server and the expansion box is disabled if the indication indicates the first server is inactive. Communication between the second server and the expansion bus is disabled if the indication indicates that the first server is active. Communication between the second server is enabled if the indication indicates that the first server is inactive. The indication includes a heartbeat message transmitted periodically to the second server. The expansion bus includes a PCI bus.
Abstract:
A computer system includes a data storage device on a first data bus, a requesting device that initiates a delayed request on a second data bus, and a bridge device that delivers the delayed request to the first data bus and, after the requesting device regains control of the second data bus, begins providing data to the requesting device while the data storage device is providing the requested data to the bridge device.
Abstract:
A computer system includes a data storage device on a first data bus, a requesting device that initiates a request for data on a second data bus, and a bridge device that delivers the request to the first data bus and receives the requested data from the data storage device. The bridge device includes a data storage buffer that temporarily stores the requested data, and a buffer management element that flushes the data from the buffer when the requesting device initiates a new request for data other than the data stored in the buffer.