Техническая Спецификация для Intel C2550 FH8065401488912
Модели
FH8065401488912
Volume 2—PCI Express Root Ports (RP)—C2000 Product Family
Architectural Overview
Intel
®
Atom™ Processor C2000 Product Family for Microserver
Datasheet, Vol. 2 of 3
September 2014
224
Order Number: 330061-002US
AtomicOps enable advanced synchronization mechanisms that are particularly useful
when multiple producers and/or multiple consumers need to be synchronized in a non-
blocking fashion. AtomicOps also enable lock-free statistics counters, for example
where a device atomically increments a counter, and host software atomically reads
and clears the counter.
Compared to locked transactions:
• AtomicOps provide lower latency, higher scalability, advanced synchronization
algorithms, and dramatically less impact to other PCIe traffic.
• Direct support for the three chosen AtomicOps over PCIe, enables easier migration
of existing high-performance, Symmetric Multi-Processing (SMP) applications to
systems that use PCIe as the interconnect for tightly-coupled co-processors.
Components that implement AtomicOp Requester capability generate any or all three of
the AtomicOps, using one or more of the supported operand sizes.
Components that implement AtomicOp Completer capability, carry out the AtomicOps
transactions. A PCIe function with AtomicOp Completer capability is not required to
support all AtomicOp type/size combinations, and is not required to support all of its
Memory Space as a target range for AtomicOps.
For increased interoperability, certain AtomicOp Completer capabilities are required to
be supported by root ports in sets if at all.
Table 12-3. Length Field Values for AtomicOp Requests
AtomicOp
TLP Length Field (in Double-Words) for Particular Operand Size
32-Bit Operands
64-Bit Operands
128-Bit Operands
FetchAdd
1
2
N/A
Swap
1
2
N/A
CAS
2
4
8