A processor architecture includes a plurality of processing elements and a bus structure. Each element has at least one input port and at least one output port, each port having at least a data bus and a valid data signal line. The bus structure contains a plurality of switches arranged to connect an output port of any first processing element to the input port of any second processing element for a time interval. Each processing element sets a value on the valid data signal line of its output port to a first logic state when the associated data bus contains a transfer value and to a second logic state when it does not contain a transfer value. Each processing element enters a waiting state for a predetermined time interval when the value on the valid data signal line of the associated input port is in the second logic state.