Another simpler method to download programs without powering off STC microcontrollers

I have seen some examples of STC microcontrollers downloading programs without powering off on the Internet. However, they all require serial port interrupts to complete. The following is a program snippet

To illustrate

Add serial port initialization code and serial port interrupt code to the debugging program to achieve 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
}
}

}