| 摘要 |
<p>PURPOSE:To suppress the increase of areas of a bus line and a semiconductor chip due to the extension of the width of the bus line and the increase of the number of ports by providing a control circuit, plural output port circuits, and plural input port circuits and transmitting output values and input values of plural ports in serial. CONSTITUTION:Since set bits outputted from a CPU 31 are converted to serial bits by a control circuit 36 and are transmitted in serial in plural output port circuits 421-42n, the number of signal lines among the control circuit 36 and plural output port circuits 421-42n is reduced. Since bits read by plural input port circuits 431-43m are transmitted in serial in plural input port circuits 431-43m and are converted to parallel bits by the control circuit 36 and are supplied to the CPU 31, the number of signal lines among plural input ports 431-43m and the control circuit 36 is reduced. Thus, the length of a bus line 37 is shortened to suppress the increase of areas of the bus line and the semiconductor chip.</p> |
