A processing unit for neural network processing includes: an instruction memory that stores tasks including one or more instructions; a data memory that stores data related to the tasks; a data flow processor that determines whether the data has been prepared for the tasks and notifies a control flow processor that preparations for the tasks have been finished in order of finished data preparation; the control flow processor that controls execution of the tasks in order of notification from the data flow processor; and a functional processor that performs computations resulting from the one or more instructions of the tasks controlled for execution by the control flow processor.