Another simpler method to download programs without powering off STC microcontrollers

To illustrate

Add serial port initialization code and serial port interrupt code to the debugging program to realize uninterrupted power download program

   TMOD|=0x20;
   SCON=0x50;
   TH1=0xfd; //12T clock 9600bps
   TL1=0xfd;
   TR1=1; 
   ES=1;
   EA=1;
   AUXR=AUXR|0x40; //Timer 1 uses 1T clock 9600*12=115200bps    

void uart(void) interrupt 4
{
   uchar cdd;
   if(RI)
   {
RI=0;
cdd=SBUF;
if(cdd==0xaa)
{
ISP_CONTR=0x60;//soft reset, start from ISP monitoring area
}
else if(cdd==0x55)
{
ISP_CONTR=0x20; //soft reset, start from user program area
} 
else
{
senddata(cdd);
}             
   }
   else
   {
TI=0;
   }
}

In addition, you need to customize the download settings in the stc download software to complete the operation video.

http://v.youku.com/v_show/id_XMTk2MTE5MTgw.html

  It can be seen from the above that it is quite troublesome, so is there a simpler method? From the above video, we know that as long as the address 0xe7 is assigned 0x60, the function of downloading the program can be completed. Then I thought, the stc download software uses the serial port, and the serial port must be used to send data to the microcontroller, and the microcontroller receiving pin is P3^0, so we only need to detect whether there is a change in the level of this pin. If there is a change, then assign 0x60 to the address 0xe7, and the automatic download command will be completed. With an idea, I started to verify. After debugging, the result was successful, indicating that I have only tested STC89C52RC. Please test whether other chips are feasible. The following is a complete program. No settings are required in the stc download software, just download the program as usual.

/*** Another simpler method for STC MCU to download programs without power off ******************************************************************
**Program function: STC MCU to download programs without power off
**Chip model: STC89C52RC
**Crystal frequency: 11.0592M                                                
**Date of writing: November 23, 2010
**Writer: wang QQ: 349259818 Email: hongfadg@163.com
**Remarks: 
*******************************************************************/
//The following are the required header files
//#include
//#include
//#include
//#include
#include  
//Define keywords for easy use
#define uchar unsigned char    
#define uint unsigned int    
#define ulong unsigned long 
sfr iap=0xe7; //Define download command
sbit p30=P3^0; //Serial port receiving pin
/* Main function
****************************************************************
**Function prototype: main()
**Function function:
**Input parameters: None
**Output parameters: None
**Remarks: Complete the main functions of the program
*******************************************************************/
main()
{
while(1) //Main loop
{ 
   if(!p30) //Judge whether there is data in the serial port
   {
    iap=0x60; //Execute the command for automatic download 
   }
}

}