Abstract: An I/O subsystem having a processor, a bridge unit, and an I/O messaging unit that couple a primary, secondary and tertiary bus in a computer system. The bridge unit is configurable to claim requests that access a messaging unit (MU) address range from the secondary bus, the MU itself being coupled to the primary bus. The MU interrupts the processor when an I/O request is posted, in response to which the processor reads from the MU pointers to an I/O messages and may then execute the I/O message. To promote the portability of software written for agents on either the primary or the secondary bus that wish to access the MU, the primary and secondary address translation units of the I/O subsystem are programmed to claim the same address translation window, where the MU address range is a portion of the primary ATU address translation window, and the secondary ATU is configured to not claim requests within the MU address range.

Abstract: An I/O subsystem having a processor, a bridge unit, and an I/O messaging unit that couple a primary, secondary and tertiary bus in a computer system. The bridge unit is configurable to claim requests that access a messaging unit (MU) address range from the secondary bus, the MU itself being coupled to the primary bus. The MU interrupts the processor when an I/O request is posted, in response to which the processor reads from the MU pointers to an I/O messages and may then execute the I/O message. To promote the portability of software written for agents on either the primary or the secondary bus that wish to access the MU, the primary and secondary address translation units of the I/O subsystem are programmed to claim the same address translation window, where the MU address range is a portion of the primary ATU address translation window, and the secondary ATU is configured to not claim requests within the MU address range.

Abstract: Real-time performance monitoring facility in an integrated circuit (IC) data processor for monitoring events related to different bus activity. The monitoring facility is accessible via a bus connection the IC. Events include device acquisition and ownership time, and the number of requests and grants on a given bus. The events are counted as occurrences and durations by a number of event counters integrated in the IC. The IC can notify software when the counters overflow. The IC may feature multiple clock domains, including, for instance, multiple bus interfaces operating at different clock frequencies, in which events from different clock domains may be tracked by the same counter. In one embodiment, the performance monitoring facility is integrated into an I/O processor (IOP) die that complies with the popular intelligent I/O (I2O) and Peripheral Components Interconnect (PCI) specifications.

Abstract: Real-time performance monitoring facility in an integrated circuit (IC) data processor for monitoring events related to different bus activity. The monitoring facility is accessible via a bus connection the IC. Events include device acquisition and ownership time, and the number of requests and grants on a given bus. The events are counted as occurrences and durations by a number of event counters integrated in the IC. The IC can notify software when the counters overflow. The IC may feature multiple clock domains, including, for instance, multiple bus interfaces operating at different clock frequencies, in which events from different clock domains may be tracked by the same counter. In one embodiment, the performance monitoring facility is integrated into an I/O processor (IOP) die that complies with the popular intelligent I/O (I2O) and Peripheral Components Interconnect (PCI) specifications.

Abstract: Real-time performance monitoring facility in an integrated circuit (IC) data processor for monitoring events related to different bus activity. The monitoring facility is accessible via a bus connection the IC. Events include device acquisition and ownership time, and the number of requests and grants on a given bus. The events are counted as occurrences and durations by a number of event counters integrated in the IC. The IC can notify software when the counters overflow. The IC may feature multiple clock domains, including, for instance, multiple bus interfaces operating at different clock frequencies, in which events from different clock domains may be tracked by the same counter. In one embodiment, the performance monitoring facility is integrated into an I/O processor (IOP) die that complies with the popular intelligent I/O (I2O) and Peripheral Components Interconnect (PCI) specifications.

Abstract: An application accelerator (AA) unit that in one embodiment is part of an I/O processor (IOP) integrated circuit. The AAU includes logic circuitry for improving the performance of storage applications such as Redundant Array of Inexpensive Disks (RAID). A boolean unit performs operations such as exclusive-or (XOR) on multiple blocks of data to form the image parity block which is written to the redundant disk array. The AAU is associated with a memory-mapped programming interface that allows software executed by a core processor in the IOP to utilize the AAU for accelerating RAID storage applications as well as local memory DMA-type transfers, using the descriptor construct.

Abstract: An application accelerator unit (AAU) that is integrated as part of a data processor, such as an I/O processor (IOP) integrated circuit. In one embodiment, the AAU includes logic for improving the performance of storage applications such as Redundant Array of Inexpensive Disks (RAID). The AAU performs boolean operations such as exclusive-or (XOR) on multiple blocks of data to form the image parity block which is then written to the redundant disk array. Additionally, the AAU may feature adder logic configured to perform an addition such as a network header checksum calculation on each data packet. The AAU includes a memory-mapped programming interface that allows software executed by a core processor in the IOP to utilize the AAU for accelerating storage and networking applications as well as for local memory DMA-type transfers, using the chain descriptor construct.

Abstract: An alignment logic circuit transferring segments of data from a first storage device to a second storage device is provided. The alignment logic circuit includes a first and second alignment stages, and an alignment control logic that controls the first and second alignment stages such that the first alignment stage outputs data aligned in a first dimension according to a second configuration, and the second alignment stage outputs data aligned in a second dimension according to the second configuration.A computer system with a DMA controller with a Memory Write and Invalidate logic circuit is provided. The Memory Write and Invalidate logic circuit generates a Memory Write and Invalidate enable signal when the DMA byte count is greater than or equal to a cacheline size, and the current transfer adders is a multiple of the cacheline size.

Abstract: A computer system is provided including a local memory, a local bus coupled to the local memory, a peripheral bus and a direct memory access (DMA) controller. The DMA controller performs DMA transfers of data between the local bus and the peripheral bus. The DMA includes a DMA queue for storing data to be transferred and a bus ownership status circuit for determining bus ownership status of the DMA controller. The DMA controller further includes a local bus interface circuit coupled to the DMA queue and to the status circuit for halting the transfer of data from the local bus to the DMA queue without relinquishing DMA ownership over the local bus when the DMA queue is full and the status circuit indicates that the DMA controller has ownership over both the peripheral bus and the local bus.

Abstract: The system and method described provide for the detection and protection of memory accesses without the overhead typically incurred by memory management units. The processor includes a guarded memory unit, which monitors memory accesses to be performed by monitoring transmissions across the memory bus. The guarded memory unit includes a plurality of registers which identify memory addresses and modes which can cause a memory protection or detection violation to occur. If a memory protection violation occurs, a cancel signal is issued to cancel the memory operation prior to completion in order to protect the memory from unauthorized accesses. If a memory violation is detected, the memory operation is permitted to complete and a fault signal is issued to the processor to identify that a memory violation has been detected.

Abstract: The system and method described provide for the detection and protection of memory accesses without the overhead typically incurred by memory management units. The processor includes a guarded memory unit, which monitors memory accesses to be performed by monitoring transmissions across the memory bus. The guarded memory unit includes a plurality of registers which identify memory addresses and modes which can cause a memory protection or detection violation to occur. If a memory protection violation occurs, a cancel signal is issued to cancel the memory operation prior to completion in order to protect the memory from unauthorized accesses. If a memory violation is detected, the memory operation is permitted to complete and a fault signal is issued to the processor to identify that a memory violation has been detected.