| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a microcomputer with a standardized built-in flash memory, in which holding omission of data in writing data to the flash memory is hardly caused by using an oscillating circuit installed in a microcomputer as standard equipment. <P>SOLUTION: This microcomputer comprises a fixed oscillating circuit 130 for outputting a clock signal with fixed frequency for generating a writing clock signal for writing data to the flash memory 100, to an external main oscillating circuit 120 for outputting a clock signal for operating the microcomputer. The flash memory 100 is designed to have a write disturb time never causing holding omission of data at the time of writing by the clock signal from the fixed oscillating circuit 130. Even if the main oscillating circuit 120 having a different frequency is externally installed, the writing of data to the flash memory 100 is performed by the clock signal of the fixed frequency of the fixed oscillating circuit 130, whereby surplus voltage by the write disturb time error in data writing is minimized so as to hardly cause the holding omission of data. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
