| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To enable a processor to perform specified processing for an I/O port in a very small number of execution cycles. <P>SOLUTION: The I/O port is mapped to a specified general register or flag register to decrease the number of cycles needed for reading from or writing to the I/O port. Further, the map is changed at interruption and at non-interruption and then the register can effectively be used in both normal processing and the interruption processing. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
