isp mode for 8051 using rs232 handshake protocol

[blazes16]

i need to know how to assign the rst pin and psen pin to rs232 in c code for the handshake protocol. i cannot start the coding because i cannot assign it.

 

[barry]

You can't do that. RST and PSEN are dedicated pins, you can't use them for your own evil purposes.

 

[blazes16]

is there any other alternative to do it?

 

[barry]

I'm not sure what you mean by "isp mode" and RS-232. First of all, an 8051 doesn't HAVE an isp mode (unless you are using some other variant--WHICH ONE?). Secondly, RS-232 is a communications protocol, it has nothing to do with isp. Thirdly, an 8051 doesn't explicitly implement RS-232, it has a UART which handles the data transmit and receive lines; you'll have to create the handshaking lines in your software.

 

[blazes16]

i'm using the p89c51rd2h which has the in system(ISP)/in application(IAP) programming function. the ISP in the datasheet are about manually reset the uC by bringing the RESET pin low and manually bring the PSEN pin high circuits. i want to do a c code where i can trigger it using software so i do not have to manually bring it to ISP mode. yes,i have done it referring to assembly language. i'm doing it in c language. i'll put the code for you to check if it can work or not because i cannot test it without knowing how to toggle the RESET pin and PSEN pin.

#include <reg51.h>
sbit CTS = RST;   //don't know how to set//
sbit RTS = PSEN; //don't know how to set//
void init();
void transmit();
void TODelay();
void main()
{
 init();
 transmit();
 ISP();
}

void init()
{
 TMOD=0x20;  
 TH1=0XFD; 
 SCON=0x50;
 TR1=1;
}

void transmit()
{
 while(RTS = 1)
 {
  CTS = 1;
  while(RI == 0)
  RI = 1;
  SBUF = 0;
 }
 TODelay();
 CTS = 0;
 TODelay();
}

void ISP()
{
 AUXR1 = 0x20;
 R0 = ; 
 R1 =0x06;
 DPTR = 0x00;
 while(ACC == 0);
 system("C:\Program Files\Flash Magic\FlashMagic.exe");
 ACC = 1;
}

void TODelay()
{
 TMOD = 0x01;
 TL0 = 0x00;
 TH0 = 0x35;
 TR0 = 1;
 while (TF0 == 0);
 TR0 = 0;
 TF0 = 0;
}

 

[barry]

I'm not really familiar with this device, but from what I can see I don't think you can reprogram the entire device (like ISP), you can only use IAP to program sections of the ROM.

I think you've got a chicken-and-egg situation: if your application code asserts RESET, then your application will stop running.

But I think you can use the bootloader to reprogram the device on startup.

 

[Jigar 4 Electronics]

Hello blazes16,

You need to read this first : https://www.edaboard.com/threads/264539/

After reading it ask your question in a simplified way so we can get what actually you want to do.

Regards.