摘要:
A computer system that implements a direct memory access (DMA) request passing protocol. The computer system may comprise a Peripheral Component Interconnect (PCI) bus that includes an electrical interface as specified by a PCI Local Bus standard. The PCI bus is coupled to at least one DMA agent and a DMA controller. The DMA agent issues DMA requests to the DMA controller using the electrical interface of the PCI bus. According to one embodiment, a system I/O controller receives the DMA requests and passes them on to the DMA controller, which arbitrates the DMA requests and passes back a grant to the system I/O controller. The system I/O controller uses the electrical interface of the PCI bus to pass the grant to the DMA agent. The same DMA request passing protocol may be implemented in any bus having an electrical interface that specifies a unique request signal line for each bus agent of the bus.
摘要:
A computer system that implements a direct memory access (DMA) request passing protocol. The computer system may comprise a Peripheral Component Interconnect (PCI) bus that includes an electrical interface as specified by a PCI Local Bus standard. The PCI bus is coupled to at least one DMA agent and a DMA controller. The DMA agent issues DMA requests to the DMA controller using the electrical interface of the PCI bus. According to one embodiment, a system I/O controller receives the DMA requests and passes them on to the DMA controller, which arbitrates the DMA requests and passes back a grant to the system I/O controller. The system I/O controller uses the electrical interface of the PCI bus to pass the grant to the DMA agent. The same DMA request passing protocol may be implemented in any bus having an electrical interface that specifies a unique request signal line for each bus agent of the bus.
摘要:
A computer system performs direct memory access (DMA) transfers according to a DMA transfer protocol. The computer system may comprise a Peripheral Component Interconnect (PCI) bus that includes an electrical interface as specified by a PCI Local Bus standard. A DMA agent, system memory, and a DMA controller are coupled to the bus. The DMA controller uses the electrical interface of the PCI bus to control a DMA transfer between system memory and the DMA agent. According to one embodiment, a system I/O controller is coupled between the DMA controller and the PCI bus. The system I/O controller passes DMA control information from the DMA controller to the DMA agent using the electrical interface of the PCI bus. The electrical interface of the PCI bus includes a plurality of address lines and a grant signal line coupled to the DMA agent, wherein the system that I/O controller transmits DMA control information to the DMA agent while asserting the grant signal line.
摘要:
A novel method and apparatus to cache System Management Mode (SMM) data with other data to improve performance and reduce latency of SMM handler routines. This method and apparatus allows SMM data and non-SMM data to be distinguished in the cache without requiring extra cache bits which can add to the cost of implementation. Since SMM data and non-SMM data can coexist in the cache, there is no need for time consuming cache flush cycles when switching between the two modes. Since SMM data can be cached, performance of SMM routines are improved. This method and apparatus defines the SMRAM address range to be a range of addresses representable by the tag, but not directly corresponding to installed main memory. When accesses are made to SMRAM addresses, they are redirected to an unused portion of main memory. Protection mechanisms may be implemented to limit access to these SMRAM addresses when not in SMM.
摘要:
A method and system, the method including, in some embodiments, calculating, by a message originator, a first check sum byte, appending the first check sum byte to the message, sending the message from the originator to a client over a single wire serial bus, and determining, by the client, a validity of the message from the originator by comparing the first check sum byte with a second check sum calculated by the client.
摘要:
A method and device are provided to monitor clock control signals from a CPU core; and calculate a time period during a sampling interval that the CPU core was used to perform work based on the clock control signals.
摘要:
A computer system having one or more components capable of being in either wake or sleep states includes a power manager and a voltage regulator. The power manager may generate a power state signal indicating the power state of the component, and this signal may be provided to the voltage regulator. The voltage regulator may supply power to the component. The target voltage level of the power may be dependent on both a current level of the power and the power state signal.
摘要:
A method for a mechanism for processor power state aware distribution of lowest priority interrupts. The method of one embodiment comprises receiving first power state information from a first component and second power state information from a second component. First task priority information from the first component and second task priority from the second component are also received. An interrupt request from a first device for servicing is received. Power state and task priority information for the first and second components are evaluated to determine which component should service the interrupt request. Either the first component or the second component is selected to be a destination component to service the interrupt request based on the power state and task priority information. The interrupt request is communicated to the destination component.
摘要:
A processor provides a configured clock rate setting for use by a peripheral set. The processor receives back from the peripheral set a feedback clock rate setting. The configured clock rate setting and the feedback clock rate setting are compared to detect over-clocking of the processor.
摘要:
In accordance with an embodiment of the present invention, a triggering event is initiated to place a processor in a low power state. The processor may or may not flush a cache upon entering the low power state depending on a power status signal. The power status signal may indicate the relative priority of power reduction associated with placing the processor in the low power state without first flushing the cache versus an increase in soft error rate in the cache associated with reducing the voltage in the low power state.