A processor capable of efficiently executing asynchronous event tasks, even though there are many tasks to run asynchronously.

摘要

The present invention relates to a processor provided in an AV decoder for reproducing multimedia data of a variable-length code length that starts an MPEG stream and is responsible for peripheral control of a main processor in an AV decoder. The counter 52 has an initial value of "1 Quot;, and the count value held in the flip-flop 51 in synchronization with the clock signal is set to 1, 2, 3, 4, 1, 2, 3, . Since this clock signal is used by the command decryption control unit 11 to control execution of the instruction, the count up by the counter 52 is performed each time the instruction decryption control unit 11 executes the instruction once. The comparator 54 compares the value counted up by the counter 52 with the integer value " 4 ", and if the count value of the counter 52 coincides with the integer value 4, the task switching signal chg_task_ex is set to a high value And switches to digest the next task.