International Business Machines Corporation

Saiichi Kawano

Masayoshi Nakano

Shinji Matsushima

Yuichi Shiraishi

Disclosed is a computer system that includes a CPU that can be operated both in a normal mode and in a power saving mode. The system further includes at least one peripheral device and a bus for allowing communication between the CPU and the peripheral device. A bus cycle detector monitors a bus cycle on the bus and a condition determiner determines the operation mode for the CPU in a specific bus cycle that is detected by the bus cycle detector. A signal generator is used to provide to the CPU, a control signal for changing the CPU's operation mode in accordance with a determination result obtained by the condition determiner. The disclosed system can reduce the operating frequency of a CPU or halt the operation of the CPU in accordance with an appropriate timing even when asynchronous communication is performed with peripheral devices.

Growing community of inventors

Sagamihara, Japan

Saiichi Kawano