摘要:
Memory access alignment in a double data rate (‘DDR’) system, including: executing, by a memory controller, one or more write operations to a predetermined address of a DDR memory module, including sending to the DDR memory module a predetermined amount of data of a predetermined pattern along with a data strobe signal; executing, by the memory controller, a plurality of read operations from the predetermined address of the DDR memory module, including capturing data transmitted from the DDR memory module; and determining, by the memory controller, a read adjust value and a write adjust value in dependence upon the data captured in response to the read operations.
摘要:
Memory access alignment in a double data rate (‘DDR’) system, including: executing, by a memory controller, one or more write operations to a predetermined address of a DDR memory module, including sending to the DDR memory module a predetermined amount of data of a predetermined pattern along with a data strobe signal; executing, by the memory controller, a plurality of read operations from the predetermined address of the DDR memory module, including capturing data transmitted from the DDR memory module; and determining, by the memory controller, a read adjust value and a write adjust value in dependence upon the data captured in response to the read operations.
摘要:
A design structure embodied in a machine readable storage medium for designing, manufacturing, and/or testing a design is provided. The design structure generally includes a computer system that includes a CPU, a memory controller, memory, a bus connecting the CPU, memory controller and memory, circuitry for providing a speculative read threshold corresponding to a selected percentage of the total number of reads that can be speculatively issued, and circuitry for intermixing demand reads and speculative reads in accordance with the speculative read threshold.
摘要:
A design structure embodied in a machine readable storage medium for designing, manufacturing, and/or testing a design for scheduling the servicing of data requests, using the variable latency mode, in an FBDIMM memory sub-system is provided. A scheduling algorithm pre-computes return time data for data connected to DRAM buffer chips and stores the return time data in a table. The return time data is expressed as data return time binary vectors with one bit equal to “1” in each vector. For each received data request, the memory controller retrieves the appropriate return time vector. Additionally, the scheduling algorithm utilizes an updated history vector to determine whether the received request presents a conflict to the executing requests. By computing and utilizing a score for each request, the scheduling algorithm re-orders and schedules the execution of selected requests to preserve as much data bus bandwidth as possible, while avoiding conflict.
摘要:
A design structure embodied in a machine readable storage medium for designing, manufacturing, and/or testing a design is provided. The design structure generally includes a processor memory system, which may include a processor and a memory controller in communication with the processor through a bus. The memory controller may include a delay circuit to receive an early read indicator corresponding to read data from a memory, the delay circuit to delay the early read indicator in accordance with a pre-determined delay such that the early read indicator is passed to the bus in advance of the read data, and a delay adjustment circuit to dynamically adjust the pre-determined delay associated with the delay circuit responsive to a change in operational speed of the processor or the bus.
摘要:
A design structure embodied in a machine readable storage medium for designing, manufacturing, and/or testing a design is provided. The design structure generally includes a computer system that includes a CPU, a storage device, circuitry for providing a speculative access threshold corresponding to a selected percentage of the total number of accesses to the storage device that can be speculatively issued, and circuitry for intermixing demand accesses and speculative accesses in accordance with the speculative access threshold.
摘要:
A design structure embodied in a machine readable storage medium for designing, manufacturing, and/or testing a design for scheduling the servicing of data requests, using the variable latency mode, in an FBDIMM memory sub-system is provided. A scheduling algorithm pre-computes return time data for data connected to DRAM buffer chips and stores the return time data in a table. The return time data is expressed as data return time binary vectors with one bit equal to “1” in each vector. For each received data request, the memory controller retrieves the appropriate return time vector. Additionally, the scheduling algorithm utilizes an updated history vector to determine whether the received request presents a conflict to the executing requests. By computing and utilizing a score for each request, the scheduling algorithm re-orders and schedules the execution of selected requests to preserve as much data bus bandwidth as possible, while avoiding conflict.
摘要:
A method and system for scheduling the servicing of data requests, using the variable latency mode, in an FBDIMM memory sub-system. A scheduling algorithm pre-computes return time data for data connected to all DRAM buffer chips and stores the return time data in a table. The return time data is expressed as a set of data return time binary vectors with one bit equal to “1” in each vector. For each received data request, the memory controller retrieves the appropriate return time vector. Additionally, the scheduling algorithm utilizes an updated history vector representing a compilation of data return time vectors of all executing requests to determine whether the received request presents a conflict to the executing requests. By computing and utilizing a score for each request, the scheduling algorithm re-orders and schedules the execution of selected requests to preserve as much data bus bandwidth as possible, while avoiding conflict.
摘要:
A design structure embodied in a machine readable storage medium for designing, manufacturing, and/or testing a design is provided. The design structure generally includes a computer system that includes a CPU, a memory controller, memory, a bus connecting the CPU, memory controller and memory, circuitry for providing a speculative read threshold corresponding to a selected percentage of the total number of reads that can be speculatively issued, and circuitry for intermixing demand reads and speculative reads in accordance with the speculative read threshold.
摘要:
A method and system for scheduling the servicing of data requests, using the variable latency mode, in an FBDIMM memory sub-system. A scheduling algorithm pre-computes return time data for data connected to all DRAM buffer chips and stores the return time data in a table. The return time data is expressed as a set of data return time binary vectors with one bit equal to “1” in each vector. For each received data request, the memory controller retrieves the appropriate return time vector. Additionally, the scheduling algorithm utilizes an updated history vector representing a compilation of data return time vectors of all executing requests to determine whether the received request presents a conflict to the executing requests. By computing and utilizing a score for each request, the scheduling algorithm re-orders and schedules the execution of selected requests to preserve as much data bus bandwidth as possible, while avoiding conflict.