Parallel execution of instructions in processing units and adjusting power mode based on monitored data dependency over a period of time

An integrated circuit comprising a set of data processing units including a first data processing unit and at least one second data processing unit operable at variable frequencies is disclosed. The integrated circuit further includes an instruction scheduler adapted to evaluate data dependencies between individual instructions in a received plurality of instructions and assign the instructions to the first data processing unit and the at least one second data processing unit for parallel execution in accordance with said data dependencies. The integrated circuit is operable in a first power mode and a second power mode. The second power mode is a reduced power mode compared to the first power mode and is adapted to adjust the operating frequency of the first data processing unit and the at least one second data processing unit in the second power mode as a function of the evaluated data dependencies.