An instruction processing circuit includes an instruction decoder, with an instruction input coupled to an instruction source and a control output coupled to the control input of an execution circuit. The instruction decoder includes a predecoding circuit, multiple freezing circuits and multiple sub-decoding circuits. The predecoding circuit has an input coupled to the instruction input and outputs coupled to control inputs of the freezing circuits, which feed the respective parallel sub-decoding circuits. The predecoding circuit detects to which type of instruction a supplied instruction belongs, and controls, dependent on the detected type, to which of the sub-decoding circuits instruction information derived from the supplied instruction will be passed and to which of the sub-decoding circuits supply of instruction information derived from a previously supplied instruction will be frozen.