| 摘要 |
<p>PROBLEM TO BE SOLVED: To easily obtain the oscillated frequency expected in an RC oscillation circuit. SOLUTION: After a 1-chip microcomputer is reset and released, an instruction of a 2nd program area of a ROM 11 is decoded, switch circuits 9-1 to 9-n are switched, in response to correction data of a nonvolatile memory 10, and an RC constant is adjusted by connecting a resistor 4 and any of oscillation adjustment resistors 8-1 to 8-n in series selectively. The current oscillating frequency of an RC oscillation circuit differs from an expected oscillation frequency, then correction data in response to the difference between both the oscillating frequencies are replaced with the correction data in the nonvolatile memory 10, and the operation above is repeated. When the adjustment of the oscillated frequency of the RC oscillation circuit is finished, the processing jumps to a heading address of a 1st program area of the ROM 11, and the execution transits to the normal operation.</p> |
