摘要 |
<p>A single-chip microcomputer includes a CPU (1), a RAM (2), a ROM (3), a timer (4), serial I/O communication logic (5), and four I/O ports (11-14). The serial I/O communication logic includes a control and status register (46), one bit (WU) of which may be utilized, when the microcomputer is connected in a distributed processing system having a shared serial communication line, to indicate that the CPU wishes to ignore a message not of interest to it. When the serial communication line again becomes free, the WU control bit is reset, enabling the CPU to intercept a new message of interest.</p> |