PURPOSE:To simplify a cycle steal controlling circuit, by using a storage holding address also as a signal for a cycle steal request or a cycle steal permisson. CONSTITUTION:Peripheral equipments 1A, 1B execute processing of input/output of data processed by a data processing device 4. Each peripheral equipment 1A, 1B is provided with comparing circuits 2A, 2B and storage protecting address generating circuits 3A, 3B, respectively. Each storage protecting address generating circuit 3A, 3B generates a storage protecting address corresponding to a degree of priority of a cycle steal request. This storage protecting address is used also as a signal of the cycle steal request or a cycle steal permission.
展开▼
