Link retry per virtual channel
AssigneeInternational Business Machines Corporation
InventorsRobert Shearer, Martha Voytovich
Life of this patent
Estimating the term…
Abstract
Methods and apparatus that allow lost packets on one virtual channel to be retried without requiring all subsequently issued packets, sent over other virtual channels, to be retried. In other words, packet retries may be performed on a “per virtual channel” basis. As a result, other virtual channels, not experiencing lost packets, may not suffer reductions in their bandwidth due to a lost packet occurring on another virtual channel.
Claims20
A method of communicating with an external device over a bus utilizing a plurality of virtual channels, each virtual channel representing a stream of data exchanged on the bus, comprising:
- maintaining at least one link retry timer for each of a plurality of virtual channels used to send data packets to the external device;
- initializing a first link retry timer in conjunction with sending a first data packet to the external device over a corresponding first virtual channel;
- and
- resending one or more previously sent and unacknowledged data packets to the external device over the corresponding virtual channel in response to detecting the first link retry timer has expired.
An integrated circuit (IC) device, comprising:
- one or more processor cores;
- a bus interface for transferring data to and from an external device via an external bus;
- and
- link retry logic circuitry configured to maintain at least one link retry timer for each of a plurality of virtual channels used to send data packets from the one or more processing cores to the external device via the bus interface and initiate the resending of data packets over a virtual channel in response to detecting expiration of a corresponding link retry timer.
A system, comprising:
- at least one bus;
- one or more external devices;
- and
- a system on a chip (SOC) having one or more processor cores and link retry logic circuitry configured to maintain at least one link retry timer for each of a plurality of virtual channels used to send data packets from the one or more processing cores to the one or more external devices via the external bus and initiate the resending of data packets over a virtual channel in response to detecting expiration of a corresponding link retry timer.
Dependencies are inferred from the claim text.