US Patent 7240138 Data transfer control apparatus

A data transfer control apparatus has a plurality of bus slaves connected to a bus master via a bus interface unit for RAM connected to the bus master via a master bus, and a transfer bus which connects the first bus slave and plural second bus slaves in the plurality of bus slaves. When an instruction to execute data transfer via the transfer bus is given by a transfer instruction signal, data transfer between one second bus slave selected from the plural second bus slaves and the first bus slave via the transfer bus is carried out in response to a control signal contained in a control signal bus on a slave bus for RAM.