Semiconductor device

Abstract

A semiconductor device in which, in principle, plural interrupt request signals can be inputted to a single interrupt terminal is provided. In the semiconductor device, peripheral devices output interrupt request signals of mutually different waveforms. When an interrupt request signal outputted from one of the peripheral devices is received, a microcomputer unit identifies the one of the peripheral devices based on the waveform of the received interrupt request signal. When an interrupt request signal is outputted from any one of the peripheral devices, the interrupt request signal is also inputted to the other ones of the peripheral devices. When one of the peripheral devices receives an interrupt request signal outputted from another one of the peripheral devices, the one of the peripheral devices can output an interrupt request signal of its own only after elapse of a predetermined output inhibition time.

What is claimed is: 
     
         1 . A semiconductor device, comprising:
 a microcomputer unit having a common interrupt terminal; and   a plurality of peripheral devices capable of outputting interrupt request signals to the interrupt terminal of the microcomputer unit,   wherein the peripheral devices output interrupt request signals of waveforms differing between the peripheral devices to the interrupt terminal of the microcomputer unit and each receive interrupt request signals outputted from the other ones of the peripheral devices,   wherein the peripheral devices are configured such that, when a first one of the peripheral devices receives an interrupt request signal outputted from a second one of the peripheral devices, the first one of the peripheral devices can output an interrupt request signal of its own only after elapse of a predetermined output inhibition time, and   wherein, when an interrupt request signal is received from one of the peripheral devices, the microcomputer unit identifies the one of the peripheral devices based on the waveform of the received interrupt request signal.