f340 关于外部振荡器配置 虽然是非原创（忘记作者大名了见谅啊）但 我认为很实用 （请站长 审查 如不合格 情与义 删除）-f340 on the external oscillator configuration although a non-original (forget the name of the forgiven ah) But I think a very useful (please review the Webmaster unqualified love and justice as delete)