| 摘要 |
<p>PURPOSE:To enhance the function of a micro-computer, by utilizing the terminal which provides a timing signal for accessing the external memory as a general- purpose output terminal in the state that the external memory is not connected, and by efficiently making the most of the terminal of LSI. CONSTITUTION:In the 1 chip LSI circuit which transfers a signal between the micro-computer and the external memory is provided the output terminal 13 which gives a timing signal for commanding the write operation to the external ROM or the external RAM, or the read operation from the external part. And when a signal of the terminal 13 is in a low level, the instruction stored in ROM is written through the input terminals 3-10 and 12, subsequently the instruction address of a signal which is read out in ROM is provided to ROM through the output terminals 26-37 of LSI, and the instruction is read out by commanding a desired address. And the terminal 13 changes its output level to a high level or a low level by the command from ROM or RAM, and is made a general-purpose output terminal in the state that ROM or RAM is not connected.</p> |
