摘要 |
<p>An internal integrated circuit clock oscillator is automatically synchronized to an external frequency reference by counting the number of periods of the internal clock oscillator (hereinafter "count") that occur within a period of a lower frequency external frequency reference then comparing the count to the reference count. When the reference count is greater than the count, the frequency of the internal clock oscillator is increased. When the reference count is less than the count, the frequency of the internal clock oscillator is decreased. When the reference count and the count are substantially the same, the frequency of the internal clock oscillator is not changed.</p> |