论文部分内容阅读
MC146818是 MOTOROLA公司生产的实时时钟芯片,它具有闰年、大小月自动识别以及与各种微处理器接口方便简单等特点(MC146818的使用方法请参考本刊1991年第8期“实时时钟/日历芯片MC146818及其应用”一文),笔者在某单片机的应用系统中使用了该芯片为系统提供实时时钟。现将使用中遇到的问题及解决办法作一介绍。以上两个问题的根源均由MC146818片内振荡器工作不稳定造成的,其后果除影响时钟走时准确性外,还易损坏芯片。笔者经反复实验和调整外部元件参数值,仍不能解决问题。笔者将图1的电路作了如图2所示的修改,才彻底解决了上述问题。
MC146818 is MOTOROLA company’s real-time clock chip, which has a leap year, the size of the automatic identification and interface with a variety of microprocessors and other features easy and convenient (please refer to the issue of the use of MC146818 No. 8, 1991 “real-time clock / calendar chip MC146818 and its application, ”a text), the author in a microcontroller application system using the chip to provide real-time clock for the system. Now the use of the problems encountered and solutions for an introduction. The root causes of these two problems are caused by the instability of the MC146818 on-chip oscillator, the consequences of which, in addition to affecting clock accuracy, are also vulnerable to damage to the chip. The author after repeated experiments and adjust the external component parameters, still can not solve the problem. I will be the circuit shown in Figure 1 made the changes shown in Figure 2, it completely solve the above problems.