Abstract: A data flow control mechanism for a bus supporting two- and three-agent transactions includes a control logic to place an indication of a request onto a computer system bus. The agent placing the indication on the bus then waits to place data corresponding to the request onto the bus until it has received an indication from another agent coupled to the bus that the other agent is ready to receive the data.

Abstract: In one embodiment of the invention, an apparatus includes address and data ports to receive an interrupt request signal in the form of address signals and data signals. The apparatus also includes decode logic to receive at least some of the address signals and data signals and provide a decoded signal at one of several decode output lines of the decode logic. A redirection table includes a send pending bit that is set responsive to the decode signal. In another embodiment, an apparatus includes dedicated interrupt ports to receive an interrupt request signal. The apparatus also includes address and data ports capable of receiving an interrupt request signal in the form of address signals and data signals, and decode logic to provide a decode signal at one of several decode output lines in response to reception of the interrupt request signal in the form of address signals and data signals.

Abstract: In one embodiment of the invention, an apparatus includes address and data ports to receive an interrupt request signal in the form of address signals and data signals. The apparatus also includes decode logic to receive at least some of the address signals and data signals and provide a decoded signal at one of several decode output lines of the decode logic. A redirection table includes a send pending bit that is set responsive to the decode signal. In another embodiment, an apparatus includes dedicated interrupt ports to receive an interrupt request signal. The apparatus also includes address and data ports capable of receiving an interrupt request signal in the form of address signals and data signals, and decode logic to provide a decode signal at one of several decode output lines in response to reception of the interrupt request signal in the form of address signals and data signals.

Abstract: In some embodiments, the invention includes an apparatus including a host bridge coupled to a processor bus. The apparatus also includes an I/O bridge coupled to the host bridge, the I/O bridge including ports to receive an interrupt request signal in the form of address signals and data signals. Decode logic receives at least some of the address signals and data signals and to provide a decoded signal responsive thereto. A redirection table includes a send pending bit that is set responsive to the decoded signal.

Abstract: A bidirectional multidrop processor bus is connected to a plurality of bus agents. Bus throughput can be increased by operating the bus in a multi pumped signaling mode in which multiple information elements are driven onto a bus by a driving agent at a rate that is a multiple of the frequency of the bus clock. The driving agent also activates a strobe to identify sampling points for the information elements. Information elements for a request can be driven, for example, using a double pumped signaling mode in which two information elements are driven during one bus clock cycle. Data elements for a data line transfer can be driven, for example, using a quad pumped signaling mode in which four data elements are driven during one bus clock cycle. Multiple strobe signals can be temporarily activated in an offset or staggered arrangement to reduce the frequency of the strobe signals. Sampling symmetry can be improved by using only one type of edge (e.g.

Abstract: Access to a memory is arbitrated by a memory arbiter. A plurality of first counters in the memory arbiter decrements service periods associated with isochronous memory requests, and a second counter decrements a service period associated with asynchronous memory requests, with the service periods for the first and second memory requests together comprising a schedule period. A scheduler logic circuit receives isochronous and asynchronous memory requests and generates a grant signal to service a received asynchronous request during the schedule period if time remains in the second counter. If there are any maintenance events signaled, the memory arbiter may correspondingly decrease the service period for the asynchronous request while the maintenance event is performed.

Abstract: A bidirectional multidrop processor bus is connected to a plurality of bus agents. Bus throughput can be increased by operating the bus in a multi pumped signaling mode in which multiple information elements are driven onto a bus by a driving agent at a rate that is a multiple of the frequency of the bus clock. The driving agent also activates a strobe to identify sampling points for the information elements. Information elements for a request can be driven, for example, using a double pumped signaling mode in which two information elements are driven during one bus clock cycle. Data elements for a data line transfer can be driven, for example, using a quad pumped signaling mode in which four data elements are driven during one bus clock cycle. Multiple strobe signals can be temporarily activated in an offset or staggered arrangement to reduce the frequency of the strobe signals. Sampling symmetry can be improved by using only one type of edge (e.g.

Abstract: One embodiment of the invention includes an apparatus, such as a bridge, for use in connection with computer system. The apparatus includes remote priority capture logic to hold task priority data indicative of a task priority of each processor in the computer system that is available for lowest priority interrupt destination arbitration (LPIDA). The apparatus also includes lowest priority logic to perform the LPIDA to select processor in the computer system is to receive an interrupt message based on contents of the remote priority capture logic. Another embodiment of the invention includes a multi-processor system having processors and a processor bus coupled to the processors. The system includes remote priority capture logic to hold task priority data indicative of a task priority of the processors while they are available for lowest priority interrupt destination arbitration (LPIDA).

Abstract: A bus agent that may be used in an enhanced highly pipelined bus architecture. In one embodiment, the bus agent includes a control interface to drive a control signal at a clock frequency, an address bus interface to drive address elements at twice the clock frequency, and a data bus interface to drive data elements at four times the clock frequency. The address bus interface drives a substantially centered address strobe transition for each address element, and the data bus interface drives a substantially centered data strobe transition for each data element.

Abstract: A bus agent that may be used in an enhanced highly pipelined bus architecture. In one embodiment, the bus agent includes a set of snoop status interfaces, an address strobe signal interface, and a bus clock interface for a bus clock signal. The bus agent of this embodiment also includes bus controller logic capable of sensing or asserting one or more of a set of snoop status signals for transaction N on the snoop status interfaces during a snoop phase to start in a bus cycle upon the later of three or more bus clock cycles of the bus clock signal after a beginning of a bus cycle of an the assertion of an address strobe signal for transaction N or two or more bus clock cycles of the bus clock signal after a beginning of a bus cycle in which a most recent snoop phase begins.

Abstract: In one embodiment of the invention, an apparatus includes address and data ports to receive an interrupt request signal in the form of address signals and data signals. The apparatus also includes decode logic to receive at least some of the address signals and data signals and provide a decoded signal at one of several decode output lines of the decode logic. A redirection table includes a send pending bit that is set responsive to the decode signal. In another embodiment, an apparatus includes dedicated interrupt ports to receive an interrupt request signal. The apparatus also includes address and data ports capable of receiving an interrupt request signal in the form of address signals and data signals, and decode logic to provide a decode signal at one of several decode output lines in response to reception of the interrupt request signal in the form of address signals and data signals.

Abstract: In one embodiment of the invention, an apparatus includes address and data ports to receive an interrupt request signal in the form of address signals and data signals. The apparatus also includes decode logic to receive at least some of the address signals and data signals and provide a decoded signal at one of several decode output lines of the decode logic. A redirection table includes a send pending bit that is set responsive to the decode signal. In another embodiment, an apparatus includes dedicated interrupt ports to receive an interrupt request signal. The apparatus also includes address and data ports capable of receiving an interrupt request signal in the form of address signals and data signals, and decode logic to provide a decode signal at one of several decode output lines in response to reception of the interrupt request signal in the form of address signals and data signals.

Abstract: In some embodiments, the invention includes an apparatus including a host bridge coupled to a processor bus. The apparatus also includes an I/O bridge coupled to the host bridge, the I/O bridge including ports to receive an interrupt request signal in the form of address signals and data signals. Decode logic receives at least some of the address signals and data signals and to provide a decoded signal responsive thereto. A redirection table includes a send pending bit that is set responsive to the decoded signal.

Abstract: A method and apparatus for supporting multiple overlapping address spaces on a shared bus includes both an address comparator and an address size indicator. The address comparator compares an address, corresponding to a request to be issued on the bus, to a plurality of address spaces. The address size indicator indicates a first address space of the plurality of address spaces to which the address corresponds.

Abstract: A memory subsystem for a computer system includes a memory controller that has a data strobe generator. The memory subsystem further includes a DRAM array coupled to the memory controller and a data path coupled to the data strobe generator and the DRAM array. The DRAM array is separated into two DRAM sets coupled to a common output bus. Access to the DRAM array begins with access to the first DRAM set. After a first CAS is applied to the first DRAM set, a data strobe is asserted which causes data from the first DRAM set to be latched into the data path. On the next clock cycle after the data strobe is asserted, the data strobe and first CAS are de-asserted. A second CAS is then applied to the second DRAM set on the next clock cycle after the first CAS is de-asserted.

Abstract: A method and apparatus for supporting multiple overlapping address spaces on a shared bus includes both an address comparator and an address size indicator. The address comparator compares an address, corresponding to a request to be issued on the bus, to a plurality of address spaces. The address size indicator indicates a first address space of the plurality of address spaces to which the address corresponds.

Abstract: In one embodiment, the invention includes an apparatus, such as a bridge, for use with a computer system having a processor bus. The apparatus includes decode logic to receive through the processor bus a task priority update transaction including data representative of a task priority designation of a processor of the computer system, and to provide a signal responsive thereto. The apparatus also includes remote priority capture logic to receive the signal responsive to the task priority update transaction and update contents of the remote priority capture logic in response thereto. In another embodiment, the invention includes an apparatus for use with a computer system having a processor bus. The apparatus includes decode logic to receive through the processor bus an end-of-interrupt (EOI) transactions and to provide an EOI signal responsive thereto.

Abstract: A “Plug and Play” type dynamic detection and binding capability for wireless peripheral devices is disclosed. The dynamic detection and binding of wireless peripherals is achieved without manual intervention, and without modifications to the host computing device's built-in operating system (BIOS). Dynamic detection and binding of a wireless peripheral device by a host is accomplished by transmitting a Device_Hail message, waiting for a Hail_Response message from a peripheral, and, upon the reception of a Hail_Response message, assigning a Peripheral Address to the responding peripheral and transmitting it to the peripheral in a Peripheral_Address_Allocation message.

Abstract: A method and apparatus is presented where for transmitting data between two or more components. Data signals are sent in parallel with a clocking signal (e.g., on a bus) so that the data signal can be latched in relation to the clocking signal. For example, two clocking signals, out of phase from each other by 180 degrees, can be sent on bidirectional clocking signal lines and data signals can be sent on a data signal line, the component receiving the clocking and data signals can latch the data signals on each high-to-low transition of either of the two clocking signals. Using the method and apparatus of the present invention, skew problems seen with other bus systems can be reduced which leads to an increase in data transfer rates.

Abstract: An agent retrieves a request, which is part of a bus transaction, from a bus. The agent then stores an identifier of the bus transaction and responds to the bus transaction after a predetermined period of time, provided the agent was not the target of the request and the target agent did not respond. In one embodiment, the agent includes a queue and a timer. A controller within the agent starts the timer if the agent is not the target of the request, a snoop phase has occurred for the request, and the request is at the top of the queue. If the timer expires without the request having received a response, then the agent responds to the request.