An Intelligent Subprocessor For Hardware Emulation With 20 MOPS Performance

Microprocessor systems used for a variety of control applications in automobiles, communications, and office equipment need hardware functions suitable for each application. Peripheral functions of single-chip microcomputers such as timers and serial communication interfaces have two major problems when used for these functions. One is that since one set of peripheral functions cannot satisfy the requirements of some applications because of lack of flexibility, a suitable set of peripheral functions for each application has to be prepared. The other is that a CPU must always intervene for peripheral functions, because those functions do not have the intelligence of a CPU. Consequently, system performance depends strongly on intervention by the CPU.