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:
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.
摘要:
The present invention provides for selectively overwriting sets of a cache as a function of a replacement management table and a least recently used function. A class identifier is created as a function of an address miss. A replacement management table is employable to read the class identifier to create a tag replacement control indicia. The cache, comprising a plurality of sets, is employable to disable the replacement of at least one of the plurality of sets as a function of the tag replacement control indicia.
摘要:
The present invention provides for a system comprising a DMA queue configured to receive a DMA command comprising a tag, wherein the tag belongs to one of a plurality of tag groups. A counter couples to the DMA queue and is configured to increment a tag group count of the tag group to which the tag belongs upon receipt of the DMA command by the DMA queue and to decrement the tag group count upon execution of the DMA command. A tag group count status register couples to the counter and is configured to store the tag group count for each of the plurality of tag groups. And the tag group count status register is further configured to receive a request for a tag group status and to respond to the request for the tag group status.
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 includes a shared memory; a memory interface unit coupled to the shared memory and operable to retrieve data from the shared memory at requested addresses, and to write data to the shared memory at requested addresses; and a plurality of processing units in communication with the memory interface and operable to (i) instruct the memory interface unit that data be loaded with reservation from the shared memory at a specified address such that any operations may be performed on the data, and (ii) instruct the memory interface unit that the data be stored in the shared memory at the specified address, wherein at least one of the processing units includes a status register having one or more bits indicating whether a reservation was lost: whether the data at the specified address in shared memory was modified.
摘要:
The present invention provides for selectively overwriting sets of a cache as a function of a replacement management table and a least recently used function. A class identifier is created as a function of an address miss. A replacement management table is employable to read the class identifier to create a tag replacement control indicia. The cache, comprising a plurality of sets, is employable to disable the replacement of at least one of the plurality of sets as a function of the tag replacement control indicia.
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 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:
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.