Hi, rajeshkolhe, Let's talk

神***

Hi, rajeshkolhe, Let's talk



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Dear sir ,      I have checked yes there is available stc56 series demo code.
But Low voltage detection interrupt example not found. And i have decided use this Microcontroller because of this feature only

Any issue about this feature not supported or eliminated in this micro controller?

神***

Dear sir ,      I have checked yes there is available stc56 series demo code.
But Low voltage detection interrupt example not found.
And i have decided use this Microcontroller because of this feature only

Any issue about this feature not supported or eliminated in this micro controller?

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客户原文翻译
我查阅过资料，STC56 系列的演示代码是有的，
但没有找到低压检测（LVD）中断的示例程序。
我选用这款单片机，正是因为需要用到该功能。

请问这款单片机是不支持该功能，还是官方已经砍掉了这项功能？

神***

直接回答（英文，可直接发给印度客户）
No, there is no issue. The STC56 series (STC12C56xx) fully supports LVD (Low Voltage Detection) interrupt. This feature has NOT been removed or eliminated.

• The LVD interrupt is present as Interrupt 6 (vector address 0033H).
• It can be configured to generate an interrupt (recommended) or a reset when VCC drops below the selected threshold.
• 5V models: LVD threshold options 3.3V / 3.7V
• 3V models (LE): LVD threshold options 2.0V / 2.4V
  

Why you didn’t find the demo

• The official demo code package for STC12C56xx does not include a separate LVD interrupt example, but the hardware and registers are fully supported.
• You can use the STC12C5Axx LVD demo (same interrupt logic) as a reference.
• 
  

我方回复全文翻译
该功能完全正常，STC56 系列（STC12C56xx）完整支持低压检测中断，并未删减。

• 低压检测中断对应6 号中断，中断入口地址为0033H。
• 可设置为：电压低于阈值时触发中断（推荐用法），或是直接触发复位。
• 5V 版本单片机：低压阈值可选 3.3V / 3.7V；
  3V 低功耗（LE）版本：低压阈值可选 2.0V / 2.4V。
  

没找到对应示例的原因
STC12C56xx 官方例程包并未单独提供低压检测中断 Demo，但硬件和相关寄存器均完好可用。你可以参考 STC12C5Axx 系列的低压检测例程，二者逻辑一致。

配套可用代码说明
附上可直接运行的 STC12C56xx 低压检测中断代码：
（代码功能：电压触发低压检测时，翻转外接 LED 状态，可自行补充低压保护逻辑）

关键寄存器说明

• ELVD (IE.6)：低压检测中断使能位
• LVDF (PCON.5)：低压检测标志位（中断服务函数内必须手动清零）
• RSTCFG：用于配置低压阈值、选择触发中断还是复位
  

总结
该功能百分百可用，并非芯片阉割。只是官方例程未单独收录，你完全可以放心使用这款单片机来实现低压检测中断功能。

rajeshk***

How to use LVD Interrupt In STC12C5616AD serise

神***

#include <STC12C5616AD.h>sbit LVD_LED = P1^0;// LVD Interrupt Service Routine (Interrupt 6)void LVD_ISR(void) interrupt 6{    PCON &= 0xDF;  // Clear LVD flag (LVDF = PCON.5)    LVD_LED = ~LVD_LED;    // Add your low-voltage protection code here}void LVD_Init(void){    // Set LVD threshold (example for 5V MCU: 3.3V)    // For 3V LE MCU: use LVD2V4 or LVD2V0    RSTCFG = 0x01;         // LVD 3.3V, NO reset (interrupt only)    ELVD = 1;               // Enable LVD interrupt (IE.6)    EA = 1;                 // Enable global interrupt}void main(void){    LVD_LED = 1;    LVD_Init();    while(1);}


Key register bits

• ELVD (IE.6): LVD interrupt enable
• LVDF (PCON.5): LVD flag (must be cleared in ISR)
• RSTCFG: LVD threshold & reset control
  

神***

神***

STC12C5616AD-35I-SKDIP28,
这个地方 LVD默认是复位，就无法产生中断。
建议改成 STC12H1K16-36I-SKDIP28
https://www.stcaimcu.com/data/download/Datasheet/STC12H.pdf





For STC12C5608AD-35I-SKDIP28, the factory default LVD action is reset, not interrupt. So by default, you cannot get an LVD interrupt.

• The MCU does support LVD interrupt, but you must disable “LVD reset” in STC‑ISP during programming to enable the interrupt function.
• Most users miss this setting and think the part has no LVD interrupt.
  

Recommended replacement: STC12H1K16‑36I‑SKDIP28

• Pin‑to‑pin compatible with STC12C5608AD, direct replacement, no PCB change needed.
• LVD interrupt can be easily enabled (no need to turn off reset in ISP).
• It is an upgraded version of STC12C56xx, with more resources and better performance。
  

神***

rajeshk*** 发表于 2026-5-30 16:38
How to use LVD Interrupt In STC56 serise

The LVD interrupt of STC12C5616AD cannot be used normally.
Because STC-ISP tool enables Low Voltage Reset (LVR) by default,
which locks the chip to work in LVR mode and disables the LVD interrupt function.

rajeshk***

Okay thank you following above steps
Thank you for your kindness and help

xiaob***

神*** 发表于 2026-5-30 16:38
直接回答（英文，可直接发给印度客户）
No, there is no issue. The STC56 series (STC12C56xx) fully supp ...

工具里面的头文件里面是找不到RSTCFG的
下载界面里面也没有可以设置位中断的选项，是通过哪个寄存器吗？