A method, computer system and set of signals are disclosed allowing for communication
of a data transfer, via a bus, between a master and a slave using a single transfer
request regardless of transfer size and alignment. The invention provides three
transfer qualifier signals including: a first signal including a starting byte
address of the data transfer; a second signal including a size of the data transfer
in data beats; and a third signal including a byte enable for each byte required
during a last data beat of the data transfer. The invention is usable with single
or multiple beat, aligned or unaligned data transfers. Usage of the three transfer
qualifier signals provides the slave with how many data beats it will transfer
at the start of the transfer, and the alignment of both the starting and ending
data beats. As a result, the slave need not calculate the number of bytes it will
transfer. In terms of multiple beat transfers, the number of data transfer requests
are reduced, which reduces the amount of switching, bus arbitration and power consumption
required. In addition, the invention allows byte enable signals to be used for
subsequent data transfer requests prior to the completion of the initial data transfer,
which reduces power consumption and allows for pipelining of data transfer requests.