STC8H8K64U_TSSOP20内置RTC

QQ6243***

当未对RTC任何初始化操作，上电RTC就会发生一次闹钟中断（在没有打开闹钟中断的情况下）

当上电对RTC闹钟写入配值并打开闹钟中断时并不会发生闹钟中断（有初始化就正常，没有任何初始化就不正常）

32G12***

RTC, 年月日时分秒，必须 外部 32768的 专用晶振，也才 RMB0.15
RTC 用外部 32768晶振； CPU 跑内部高速 HIRC时钟；
你外部挂了 32768 高精准 RTC 时钟，就可以用内部硬件根据外部时钟自动校准内部高速 HIRC时钟，如 45MHz
另外您可以看下手册的这个章节，看看是不是哪里设置的不对：

神***

乘风***

我按照你的方法试了一下，没有遇到你说的那种现象。

附件是我的测试程序，你可以将RTC_config配置函数屏蔽掉，试试不对RTC任何初始化操作情况下，上电会不会产生闹钟中断。
测试例程在中断函数里面判断是闹钟中断的话，翻转一个带指示灯的IO口，并设置B_Alarm标志：

 if(RTCIF & 0x80)    //闹钟中断
        {
                P11 = !P11;
                RTCIF &= ~0x80;
                B_Alarm = 1;
        }
复制代码

主循环里判断B_Alarm被置位的话，通过CDC串口打印一串数据：

if(B_Alarm)
        {
            B_Alarm = 0;
            printf("RTC Alarm!\r\n");
        }
复制代码

所以不管通过指示灯还是CDC串口都可以判断是否产生了闹钟中断。
如果还是觉得有问题的话，请提供可以复现问题的测试例程。

jm***

STC32G12*** 发表于 2023-3-17 11:14
RTC, 年月日时分秒，必须 外部 32768的 专用晶振，也才 RMB0.15
RTC 用外部 32768晶振； CPU 跑内部高速 H ...

You say

you have a 32768 high-precision RTC clock externally, you can use the internal hardware according to the external The clock automatically calibrates the internal high-speed HIRC clock, such as 45MHz.

Is there any example, of how the 32768 is used to automatically calibrate the internal high-speed HIRC clock ?

What HIRC clock MHz choices can be calibrated ?

32G12***

附件有测试范例，您可以测试看看：
使用STC出厂前用专业时钟调校设备，调校的如下10种常用高精准内部HIRC频率--STC8H8K64U
22.1184MHz,24MHz,27MHz,30MHz,33.1776MHz,35MHz,36.864MHz,40MHz,44.2368MHz,48MHz
在用户程序区用户自己选择设置如上STC出厂前调校的这10种内部高精准的HIRC的频率--STC8H8K64U
===常温下STC出厂前用专业的高精准设备调校的这10个固定频率时钟误差 < + - 0.3%
===没有压飘，只有+-1%附近的温漂【-40度 ~ +85度】
而如用户使用在ISP烧录时任意设置的频率，虽然范围很宽很灵活，但如用户使用第三方不专业的USB转串口来烧录，
来校准成其他的频率，这有可能会将第三方不专业工具的时钟误差，在用户ISP下载时重新校准频率而带入芯片内部
即使用户要设置特殊的频率，也请使用 STC的专业工具 STC-USB Link1D
===用STC-ISP下载时设置任意频率, 请使用STC-USB Link1D来校准内部高精准HIRC的频率，
===这个STC-USB Link1D 专业工具专门外挂了22.1184MHz晶振来ISP下载时校准内部时钟到任意频率
===STC-USB Link1D是【专业仿真器，专业在线全自动下载器/无需手工停电，专业脱机烧录器，专业时钟校准器】
这是超级重点，不要那么强大的内部时钟不会自己在程序区自己任意设置

jm***

Thank you.
That reply refers to initial calibrate of the HIRC, using the stored values, or using Link1D, to calibrate to ±0.3%

You stated before

You have a 32768 high-precision RTC clock externally, you can use the internal hardware according to the external The clock automatically calibrates the internal high-speed HIRC clock, such as 45MHz.

Which suggests the precision RTC crystal can calibrate (somehow?) the HIRC, as other vendors can do ?  Or do I not understand what you wrote ?

Can you somehow auto calibrate the HIRC for run-time correction of the average MHz, to (much) better than the ±0.3% ?
or if it is not supporting Automatic calibrate, is there some way to capture a HIRC timer reading, using the RTC crystal signal ?

32G12***

RTC, month, day, hour, minute, second, must have an external 32768 dedicated crystal oscillator。

jm***

I am trying to understand your comment in #2

You have a 32768 high-precision RTC clock externally , you can use the internal hardware according to the external The clock automatically calibrates the internal high-speed HIRC clock , such as 45MHz.

To calibrate such as 45MHz against 32.768kHz crystal, as one example you would capture 45MHz divided by 1372=TC and sample TC 3 times
samples of 001 or 000 is HIRC is too slow, 011 is 'locked' and 111 is too fast.

I am unclear of the STC8H or any STC MCUs have that level of hardware calibrate support ?  

32G12***

Before using STC factory, use professional clock calibration equipment to adjust the following 10 commonly used high-precision internal HIRC frequencies - STC8H8K64U

22.1184MHz,24MHz,27MHz,30MHz,33.1776MHz,35MHz,36.864MHz,40MHz,44.2368MHz,48MHz

In the user program area, the user chooses to set the frequency of these 10 kinds of internal high-precision HIRC, STC8H8K64U, which are calibrated before the STC leaves the factory