Cooperative operation method and a mobile communication terminal device

Stored in the nonvolatile memory area 37 of the storage unit 35 connected to the host processor 31 in the host unit 30, a program for the engine processor for execution by the engine processor 41 of the engine unit 40, the engine unit from the host unit 30 40 forwards towards. The engine unit 40 has received the program engine, and stores the program for the engine processor, the storage unit 42 of the connected volatility engine processor 51. Thereafter, the host unit 30, an execution command which is one specific program of the programming engine processor stored in the storage unit 42 notifies to the engine section 40, to be executed by the engine processor 41. As a result, even when configured to include a host portion and the engine unit, that providing a nonvolatile large-capacity storage area to the engine unit 40 becomes unnecessary, the mobile communication terminal apparatus with a compact structure can.