Pipelining:
The OCP allows pipelining of transfers. To support this feature, the return of read data and the provision of write data may be delayed after the presentation of the associated request.
Response:
The OCP separates requests from responses. A slave can accept a command request from a master on one cycle and respond in a later cycle. The division of request from response permits pipelining. The OCP provides the option of having responses for Write commands, or completing them immediately without a response (posted write model).
Threads and Connections:
To support concurrency and out-of-order processing of transfers, the extended OCP supports the notion of multiple threads. Transactions within different threads have no ordering requirements, and so can be processed out of order. Within a single thread of data flow, all OCP transfers must remain ordered.While the notion of a thread is a local concept between a master and a slave
communicating over an OCP, it is possible to globally pass information from initiator to target using connection identifiers. Connection information helps to identify the initiator and determine priorities at the target.
Interrupts, Errors, and other Sideband Signaling:
The OCP refers to all such communication as sideband (or out-of-band) signaling, since it is not directly related to the protocol state machines of the dataflow portion of the OCP. The OCP provides support for such signals through sideband signaling extensions.
Errors are reported across the OCP using two mechanisms. The error response code in the response field describes errors resulting from OCP transfers that provide responses. Posted write-type commands do not generate a response and cannot use the in-band reporting mechanism. The second method for reporting errors across the OCP is an out-of band error field. This signal reports more generic sideband errors, including those associated with posted write commands.
The OCP allows pipelining of transfers. To support this feature, the return of read data and the provision of write data may be delayed after the presentation of the associated request.
Response:
The OCP separates requests from responses. A slave can accept a command request from a master on one cycle and respond in a later cycle. The division of request from response permits pipelining. The OCP provides the option of having responses for Write commands, or completing them immediately without a response (posted write model).
Threads and Connections:
To support concurrency and out-of-order processing of transfers, the extended OCP supports the notion of multiple threads. Transactions within different threads have no ordering requirements, and so can be processed out of order. Within a single thread of data flow, all OCP transfers must remain ordered.While the notion of a thread is a local concept between a master and a slave
communicating over an OCP, it is possible to globally pass information from initiator to target using connection identifiers. Connection information helps to identify the initiator and determine priorities at the target.
Interrupts, Errors, and other Sideband Signaling:
The OCP refers to all such communication as sideband (or out-of-band) signaling, since it is not directly related to the protocol state machines of the dataflow portion of the OCP. The OCP provides support for such signals through sideband signaling extensions.
Errors are reported across the OCP using two mechanisms. The error response code in the response field describes errors resulting from OCP transfers that provide responses. Posted write-type commands do not generate a response and cannot use the in-band reporting mechanism. The second method for reporting errors across the OCP is an out-of band error field. This signal reports more generic sideband errors, including those associated with posted write commands.
No comments:
Post a Comment