DEVICE FOR ACCESSING A LARGE-BIT EXTERNAL DEVICE BY A SMALL-BIT MICROPROCESSOR

摘要

PURPOSE: A device is provided to access an external device without a limitation of a data size of the external device by enabling to access a 16-bit or 32-bit external device using an 8-bit or 16-bit microprocessor. CONSTITUTION: The device for accessing a large-bit external device by a small-bit microprocessor comprises: a 16-bit bi-direction data storage control part(12) which outputs a signal for controlling a 16-bit bi-direction data storage according to a chip select signal outputted from a 16-bit microprocessor(11) and transfers the chip select signal to an 32-bit external device(14); and a 16-bit bi-direction data storage part(13) which stores a bi-direction data between the 16-bit microprocessor(11) and the 32-bit external device(14) according to the control of the 16-bit bi-direction data storage control part and makes the 16-bit microprocessor access the 32-bit external device.