Method and apparatus for transferring data on a split bus in a data processing system
 A bus protocol for a split bus (50, 60) where each device (10, 20, 30) coupled to the bus has an age-based queue (12, 24, 34) of pending transactions. Queues are updated as transactions are executed. A central arbiter (40) has a copy of each device's queue (44). A priority transaction is determined from among all the queues in the arbiter. A data transaction index (DTI) is broadcast during the data tenure to all devices indicating the position in the queue of the next transaction. The index allows out-of-order data transfers without the provision of a static tag during the address tenure. Queues maintain a history of pending transactions. In one embodiment, each device receives a separate data bus grant (DBG), allowing a single provision of the index to both a source and a sink device. 
Motorola, Inc.
G
G06F
inventional
Michael Julio David William Brian Keith Michael Dean
Garcia Todd Reynolds Snyder