Abstract: A system may comprise multiple master/slave devices coupled to a common bus, where one of the devices may operate as the current master device and the other devices may operate as current slave devices. Current slave devices may embed bus ownership request information within response packets transmitted in response to standard bus operations, such as reads and writes, issued by the current master device. When the current master device is idle, its bus interface may continually poll the current slave devices at regular intervals, according to a specified protocol, to ascertain whether any of them are requesting bus ownership. A response to a request for bus ownership received by the current master device may be configured according to desired system functionality. In one system, ownership may always be transferred to the requesting device.

Abstract: A computer system, more generally a master-slave system, may be configured with interrupt handling capability without additional dedicated interrupt lines. An interrupt condition may be bound with its relevant cause information and transmitted by a slave device during a typical response to any operation that a master device may have issued, such as a read or a write. In addition, a link level protocol may be configured in the bus interface of the master device to continually poll specified addresses, or to issue a unique command targeted at interrupts. The master device may be unaware of the unique requests, as the bus may remain idle as seen by the master device. The response to the unique requests may be similar to the interrupt message information transmitted as part of a response to a standard request that may be made by the master device.