摘要:
A peripheral interconnect for a computer system comprising a bridge, a peripheral bus, and a peripheral device, wherein at least one of these components is adapted to selectively operate in either a high performance mode or a low performance mode, the high performance mode using a first operating speed and a first protocol, and the low performance mode using a second operating speed which is lower than said first operating speed, and a second protocol which is different from the first protocol. The disclosed embodiment provides a high performance mode with a 100 MHz speed and a protocol that disallows pacing, and a low performance mode that uses a 66 MHz or 33 MHz speed and a standard PCI protocol that allows pacing. The high performance operating speed can be twice the low performance operating speed, by doubling the clock frequency and clocking data on only one clock edge, or by clocking data on both a rising edge and a falling edge of a clock signal while operating at the lower clock frequency. High performance adapters can provide split transaction capability, with a high performance bridge having the ability to support split transactions or alias split transactions to delayed transactions. Backward compatibility may also be provided for optional features such as hot-pluggability.
摘要:
A method and apparatus is provided in which Pipelined Packet Transfers (PPT) are implemented. The PPT methodology includes a request phase and a response phase. The PPT request phase involves a PPT request master delivering to a PPT request target a source address, a destination address and an information packet for the interrupt being requested. The PPT response phase involves the PPT request target becoming a PPT response master with the PPT response master delivering to a PPT request master a destination address and a data packet which includes the interrupt processing information. Pipelined Packet transfers (PPT) are ordered in accordance with a predetermined processing priority to improve performance and avoid deadlock.
摘要:
A method and apparatus is provided in which Pipelined Packet Transfers (PPT) are implemented. The PPT methodology includes a request phase and a response phase. The PPT request phase involves a PPT request master delivering to a PPT request target a source address, a destination address and an information packet for the interrupt being requested. The PPT response phase involves the PPT request target becoming a PPT response master with the PPT response master delivering to a PPT request master a destination address and a data packet which includes the interrupt processing information. Pipelined Packet transfers (PPT) are ordered in accordance with a predetermined processing priority to improve performance and avoid deadlock.
摘要:
A method and system for supporting multiple Peripheral Component Interconnect (PCI) local buses through a single PCI host bridge having multiple PCI interfaces within a data-processing system are disclosed. In accordance with the method and system of the present invention, a processor and a system memory are connected to a system bus. First and second PCI local buses are connected to the system bus through a PCI host bridge. The first and second PCI local buses have sets of in-line electronic switches, dividing the PCI local buses into PCI local bus segments supporting a plurality of PCI peripheral component slots for connecting PCI devices. The sets of in-line electronic switches are open and closed in accordance with bus control logic within the PCI host bridge allowing up to fourteen or more PCI peripheral component slots for connecting up to fourteen PCI devices to have access through a single PCI host bridge to the system bus. An internal PCI-to-PCI bridge is provided to allow a PCI device to share data with another PCI device as peer-to-peer devices across the first and second PCI local bus segments.
摘要:
A methodology and implementing system are provided in which pipelined read transfers or PRTs are implemented. The PRTs include a request phase and a response phase. The PRT request phase involves a PRT request master delivering to a PRT request target, a source address, a destination address and the transfer size for the data being requested. In the PRT response phase, the PRT request target becomes a PRT response master, i.e. a PCI bus master, and initiates a completion of the transaction that was requested in the originating PRT request.
摘要:
A data processing system includes a processor, system memory and a number of peripheral devices, and one or more bridges which may connect between the processor, memory and peripheral devices and other hosts or peripheral devices such as in a network. A bridge, such as a PCI host bridge, connects between a primary bus (e.g system bus) and a secondary bus. The host bridge provides a dual host bridge function which creates two secondary bus interfaces. This allows increased loading capability under one dual host bridge compared to a lesser number of slots allowed under one normal host bridge. Also included is additional control logic for providing arbitration control and for steering transactions to the appropriate bus interface. Additionally, peer to peer support across the two secondary bus interfaces in provided.
摘要:
A method and apparatus are provided in which a control scheme is implemented to enable a PCI bus to operate more than two PCI slots into which PCI devices may be installed. The PCI slots are checked to determine if a PCI device is installed in the slots and the speed at which the installed PCI devices are capable of running. If any of the slots has a 33 MHz device installed in any of the slots, the system is enabled to run more than two slots, and all of the PCI devices will run at 33 MHz. When no 33 MHz cards or devices are installed in the PCI slots, and PCI devices are only installed in the first two slots, then the system is enabled to run only the first two slots at the speed of 66 MHz. In one alternative embodiment, a default configuration routine sets the PCI bus speed at one of the operating frequencies and modifies that default if it is determined during a system configuration cycle that another speed is more appropriate.
摘要:
A method of registering a newly added peripheral device with a computer system by responding with a status message from the device to a bus of the computer system, in response to an access attempt, and within a predetermined time period from the deasserting of the reset signal applied to device, so as to avoid stalling and thereby avoid the need to reboot the system in order to initialize the new peripheral device with the operating system. The device may be allowed to initially send a retry response, provided the response occurs during an initial latency period which is less than the predetermined time period. The invention also enables the peripheral device to respond to non-configuration cycles immediately following configuration completion. Internal logic of the peripheral device can be initialized after responding with the status message. Non-configuration access to the peripheral device can be prevented until it is ready to respond, by setting a bit (in the configuration space of the peripheral device to indicate that the peripheral device is ready.
摘要:
A methodology and implementing system are provided in which pipelined read transfers or PRTs are implemented. The PRTs include a request phase and a response phase. The PRT request phase involves a PRT request master delivering to a PRT request target, a source address, a destination address and the transfer size for the data being requested. In the PRT response phase, the PRT request target becomes a PRT response master, i.e. a PCI bus master, and initiates a completion of the transaction that was requested in the originating PRT request. Pipelined read transfers are ordered in accordance with a predetermined processing priority to improve performance and avoid deadlocks.
摘要:
A method and system for supporting multiple Peripheral Component Interconnect (PCI) local buses through a single PCI host bridge having multiple PCI interfaces within a data-processing system are disclosed. In accordance with the method and system of the present invention, a processor and a system memory are connected to a system bus. First and second PCI local buses are connected to the system bus through a PCI host bridge. The first and second PCI local buses have sets of in-line electronic switches, dividing the PCI local buses into PCI local bus segments supporting a plurality of PCI peripheral component slots. The sets of in-line electronic switches are open and closed in accordance with bus control logic within the PCI host bridge allowing up to fourteen PCI peripheral component slots to have access through a single PCI host bridge to the system bus.