摘要:
A symmetrical multiprocessing system is provided that includes a central interrupt control unit. The central interrupt control unit is coupled to a plurality of processing units and to a plurality of interrupt sources. The interrupt sources include a plurality of peripheral devices coupled to a first peripheral bus, such as a PCI bus. The interrupt sources also include devices coupled to a second peripheral bus, such as an ISA bus. The central interrupt control unit is operative in two modes. In a first mode, referred to as a pass through mode, interrupts from ISA peripheral devices are provided through an interrupt controller, such as cascaded type 8259 interrupt controllers, to the central interrupt control unit. The central interrupt control unit then passes the interrupt directly to a master processing unit. PCI interrupts are provided through a PCI mapper to other available interrupt inputs of the interrupt controller. The pass through mode advantageously allows backwards compatibility of the system with traditional operating systems such as DOS. During the advanced operating mode, the central interrupt control unit causes the PCI mapper to be disabled. In the advanced mode, interrupts from both PCI devices and ISA devices are provided directly to the central interrupt control unit. Since the PCI mapper is disabled during the advanced mode, additional ISA peripheral devices may be supported within the system without contending with PCI interrupts.
摘要:
An integrated processor is provided that includes a CPU core, a local bus coupled to the CPU core, and a variety of peripheral such as a memory controller, a direct memory access controller, and an interrupt controller coupled to the local bus. A bus interface unit is further provided to interface between the CPU local bus and a PCI standard multiplexed peripheral bus. The CPU core, the memory controller, the direct memory access controller, the interrupt controller, and the bus interface unit are all incorporated on a common integrated circuit chip. A local bus control unit is further provided that is capable of generating a loading signal and an address strobe signal synchronously with certain bus cycles that are executed on the PCI bus. The local bus control unit allows external peripheral devices that are compatible with the CPU local bus protocols to be connected through the PCI bus. A latch is coupled to the multiplexed address/data (A/D) lines of the PCI bus and includes a set of output lines coupled to the address input lines of the externally connected peripheral device. The external latch is latched by the loading signal. The cycle definition signals of the PCI bus are further latched within the external latch to provide memory/IO and read/write signals to the external peripheral device. The data lines of the peripheral device may be connected directly to the multiplexed address/data lines of the PCI bus.
摘要:
A non-volatile memory controller is provided which is connectable directly to the local bus of a computer system and which allows access to one or more 32-bit banks of ROM and to an 8-bit bank of non-volatile memory. The 8-bit bank of non-volatile memory may be used, for example, to store BIOS code, and may be implemented using a ROM or flash memory device. The non-volatile memory controller includes a data router, a sequencer, and a set of output latches for routing the 8-bit BIOS code (stored within the 8-bit bank) to selected byte lanes of the local bus and for converting the 8-bit data to 32-bit local bus data. The non-volatile memory controller further supports high performance, 32-bit accesses to the user software stored within the 32-bit banks. If the system designer or user instead must maximize the memory capacity of the computer system, the 8-bit bank of memory may be replaced with a larger 32-bit bank of memory. In this configuration, a control signal is provided to the non-volatile memory controller to indicate that a 32-bit bank is connected rather than an 8-bit bank. The control signal causes the sequencer and the data router to be disabled. When a memory access to the 32-bit bank is executed, the non-volatile memory controller accesses the data within the 32-bit bank and drives the data directly on the CPU local bus.
摘要:
A dockable computer system is capable of performing hot docking or warm docking. Hot docking refers to an ability to dock when the portable computer or docking station are running at full power. Warm docking refers to an ability to dock when the portable computer and docking station are running in a reduced power state. The dockable computer system employs a docking agent which is capable of quieting (rendering inactive) the buses of the portable computer and docking station in response to a notice signal. The notice signal is indicative of a change of states from the undocked state to the docked state or from the docked state to the undocked state. The notice signal can be provided from software, a user-actuated switch, or an infrared signal. The docking agent preferably quiets the system bus by idling the system bus or asserting bus ownership or bus mastership over the system bus. The docking agent is able to assert bus ownership or bus mastership over the system bus. Alternatively, the docking agent can perform a software idle subroutine or an interrupt subroutine which idles the system bus. Preferably, the system bus is idled by disabling clock signals to it. Preferably, the docking agent also removes bus ownership requests, interrupt requests, and DMA requests from the station bus and system bus.
摘要:
An integrated processor that employs a bus interface unit to accommodate high performance data transfers via an external peripheral interconnect bus with multiplexed address/data lines. The peripheral interconnect bus, which may be a PCI standard bus, accommodates data transfers between an internal bus of the integrated processor and PCI peripheral devices. The integrated processor further includes a sub-bus control unit that generates a set of side-band control signals that allow the external derivation of a lower performance secondary bus, such as an ISA bus, without requiring a complete set of external pins for the secondary bus on the integrated processor. The derivation of the secondary bus is accomplished with an external data buffer and an external address latch which are controlled by the side-band control signals. Separate address and data lines from the integrated processor for the secondary bus are not required. Accordingly, high performance peripheral devices are supported by the integrated processor as well as lower performance, lower-cost peripherals without a significant increase in the pin-count of the integrated processor. Accordingly, overall cost of the integrated processor is kept low while a wide range of peripheral devices are supported.
摘要:
An apparatus for managing system interrupt operations in a computing system including a processing unit and peripheral devices. The apparatus comprises a transmission circuit for transmitting signals which effects operative connection among the peripheral devices and the processing unit; an interrupt drive circuit for generating interrupt signals associated with each peripheral device drives the transmission circuit from a first signal level to a second signal level to effect generating an interrupt signal; and an acknowledge drive circuit for generating an acknowledge signal by the processing unit. Each acknowledge drive circuit drives the transmission circuit from an initial signal level to an indicating signal level to effect generation of an acknowledge signal, and drives the transmission circuit from the indicating signal level to the initial signal level upon termination of the acknowledge signal. In its preferred embodiment, the apparatus provides that no peripheral device can generate an interrupt signal for a predetermined time interval following termination of an acknowledge signal.
摘要:
An apparatus for managing communication within a computing system which includes a processing unit and a plurality of peripheral units. The processing unit receives information from a plurality of loci within the computing system and determines an enablement profile in response to such information according to predetermined criteria. The processing unit responds to the enablement profile to selectively enable specified peripheral units. The apparatus comprises a monitoring circuit for monitoring the enablement profile; a logic circuit for logically treating the enablement profile and generating a feedback signal representative of the enablement profile; and a transmission circuit for communicating the feedback signal from the logic circuit to the processing unit. The processing unit responds to the feedback signal to determine whether to employ a transfer trapping discipline whereby transfers destined for a non-enabled peripheral unit are stored until the non-enabled unit is enabled. The invention further comprises a method for managing communications within such a computing system comprising the steps of monitoring the enablement profile; generating a feedback signal representative of the enablement profile; communicating the feedback signal to the processing unit; and configuring the processing unit to respond to the feedback signal to determine whether to employ a transfer trapping discipline.
摘要:
Systems and methods for booting a programmable processor such as a DSP that is incorporated into an HDA codec. The codec and a system memory containing boot program instructions are connected to an HDA bus. In a first mode, the DSP receives boot program instructions via the HDA bus and boots using these instructions. In a second mode, the DSP boots from instructions that are contained in a memory that is connected to the DSP. In one embodiment, the memory connected to the DSP is a component of a plug-in card, and the DSP is configured to determine whether the plug-in card is present, then boot from the memory on the plug-in card if it is present or boot from the system memory via the HDA bus if the plug-in card is not present.
摘要:
A dedicated bus between a central processing unit and a peripheral unit, such as a graphics controller driving a video display, provides enhanced capability in an environment in which signal processing occurs within the central processing unit. The dedicated bus relieves other data buses, such as the PCI bus, of the need to communicate large amounts of data, such as decompressed video data. The resulting system supports high bandwidth transmissions of decompressed video data, enabling high resolution 24 bit full motion video and multiple data stream video.
摘要:
A dockable computer system is capable of performing symmetrical multi-processing operations. More particularly, the dockable computer system includes a portable computer and a host station (docking station), each including a resident CPU. The dockable computer system is capable of operating in a docked state in which the portable computer is physically joined with the host station and an undocked state in which the portable computer is physically separate from the host station. In the docked state, the dockable computer system is capable of performing demanding computational tasks such as video conferencing as one of the CPUs in either the portable computer or host station is dedicated to the video conferencing operation. The dockable computer system preferably includes a communication channel for transmitting multi-processing support signals between the portable computer and the host station. Multi-processing support signals include synchronization signals, cache coherency signals, and interrupt distribution signals such as the LOCK signal, PLOCK signal, FLUSH signal, EADS signal, INTR signal or INTACK signal. The communication channel may be a dedicated bus or may be provided through a docking bridge between the portable computer and host station. The dockable computer system advantageously optimizes CPU resources when the dockable computer system is in a docked state.