摘要:
A system and method for communicating command parameters between a processor and a memory flow controller are provided. The system and method make use of a channel interface as the primary mechanism for communicating between the processor and a memory flow controller. The channel interface provides channels for communicating with processor facilities, memory flow control facilities, machine state registers, and external processor interrupt facilities, for example. These channels may be designated as blocking or non-blocking. With blocking channels, when no data is available to be read from the corresponding registers, or there is no space available to write to the corresponding registers, the processor is placed in a low power “stall” state. The processor is automatically awakened, via communication across the blocking channel, when data becomes available or space is freed. Thus, the channels of the present invention permit the processor to stay in a low power state.
摘要:
A method, an apparatus, and a computer program are provided for controlling memory access. Direct Memory Access (DMA) units have become commonplace in a number of bus architectures. However, managing limited system resources has become a challenge with multiple DMA units. In order to mange the multitude of commands generated and preserve dependencies, embedded flags in commands or a barrier command are used. These operations then can control the order in which commands are executed so as to preserve dependencies.
摘要:
The present invention provides a method and apparatus for creating memory barriers in a Direct Memory Access (DMA) device. A memory barrier command is received and a memory command is received. The memory command is executed based on the memory barrier command. A bus operation is initiated based on the memory barrier command. A bus operation acknowledgment is received based on the bus operation. The memory barrier command is executed based on the bus operation acknowledgment. In a particular aspect, memory barrier commands are direct memory access sync (dmasync) and direct memory access enforce in-order execution of input/output (dmaeieio) commands.
摘要:
A system and method for communicating instructions and data between a processor and external devices are provided. The system and method make use of a channel interface as the primary mechanism for communicating between the processor and a memory flow controller. The channel interface provides channels for communicating with processor facilities, memory flow control facilities, machine state registers, and external processor interrupt facilities, for example. These channels may be designated as blocking or non-blocking. With blocking channels, when no data is available to be read from the corresponding registers, or there is no space available to write to the corresponding registers, the processor is placed in a low power “stall” state. The processor is automatically awakened, via communication across the blocking channel, when data becomes available or space is freed. Thus, the channels of the present invention permit the processor to stay in a low power state.
摘要:
A system and method are provided for setting up a direct memory access for a first processor. The system includes the first processor and a local memory. The local memory is coupled to the first processor. A first direct memory access controller (DMAC) is coupled to the first processor and the local memory. A system memory is in communication with the first DMAC. A second processor is in communication with the first DMAC such that the second processor sets up the first DMAC to handle data transfer between the local memory and the system memory. The second processor is interrupted when the first DMAC finishes handling the data transfer.
摘要:
The present invention provides a method and a system for providing cache management commands in a system supporting a DMA mechanism and caches. A DMA mechanism is set up by a processor. Software running on the processor generates cache management commands. The DMA mechanism carries out the commands, thereby enabling the software program management of the caches. The commands include commands for writing data to the cache, loading data from the cache, and for marking data in the cache as no longer needed. The cache can be a system cache or a DMA cache.
摘要:
Disclosed is a coherent cache system that operates in conjunction with non-homogeneous processing units. A set of processing units of a first configuration has conventional cache and directly accesses common or shared system physical and virtual address memory through the use of a conventional MMU (Memory Management Unit). Additional processors of a different configuration and/or other devices that need to access system memory are configured to store accessed data in compatible caches. Each of the caches is compatible with a given protocol coherent memory management bus interspersed between the caches and the system memory.
摘要:
The present invention provides for atomic update primitives in an asymmetric single-chip heterogeneous multiprocessor computer system having a shared memory with DMA transfers. At least one lock line command is generated from a set comprising a get lock line command with reservation, a put lock line conditional command, and a put lock line unconditional command.
摘要:
The present invention provides a method for a processor to write data to a cache or other fast memory, without also writing it to main memory. Further, the data is “locked” into the cache or other fast memory until it is loaded for use. Data remains in the locking cache until it is specifically overwritten under software control. The locking cache or other fast memory can be used as additional system memory. In an embodiment of the invention, the locking cache is one or more sets of ways, but not all of the sets or ways, of a multiple set associative cache.
摘要:
Disclosed is an apparatus for controlling or managing the transmission of data packets over a multiplexed communication path, referred to herein as a bus, on a priority basis up to a given authorized BW (Bandwidth), in a given operational time period, for presently authorized devices or applications. Non-managed (not presently authorized) bus requests are handled in a prior art “best effort” basis.