the freaking serial port problem

[sirishy2k]

100nk100

i am trying to burn the code into P89V51RD2 using FLASH MAGIC
but every time i get this error:--
UNABLE TO CONNECT AT THE SPECIFIED BAUD RATE.TRY REDUCING THE BAUD RATE.RESET THE HARDWARE INTO ISP MODE AGAIN
and i tried to communicate using windows hyper terminal and even that failed
and i set the correct baud rate(9600) for the serial port(enabled COM1) in my device manager.
But the board was working fine with my friends computer.
can anyone tell me what is the problem ,is their any other software like flash magic ??

 

[amol_shah]

serial port not working

1) could be problem with ur com port.
2) whats the cap value used for max 232 & the decoupling capacitor values?

 

[sirishy2k]

100nk100 caps

100nk100
But it worked fine previously i burned a led blinking program into the chip this problem started after few days.

 

[amol_shah]

flash magic serial port problem

use 10µf cap for max 232 (between pin 1 & 3, pin 4 & 5, pin 2 & vcc, pin 6 an gnd) and 100µf specially for max 232
also check the IC's

 

[sirishy2k]

i even did that but still its not working

 

[ctownsend]

Start hyperterminal or any other terminal program. Set up com port, baud rate etc.

Send an uppercase "U". If it echoes back, the ISP is working, and your com port is working.

Did you try another device on your com port to verify that the port is working?

Is PSEN low when it is in programming mode? How is PSEN being controlled? Is it through com port, or manually switched? What about reset?

ALWAYS post your ISP circuit so people can help you troubleshoot.

I found that the ISP is very troublesome unless I used an 11.0592 MHz clock. (that is, it will program at most speeds, usually 57 600 baud).

If you figure it out, please post results so others can benefit.

Good Luck

 

[manish12]

replace max 232 , and your mc too , it is damage ,

or with one comm port , two application ?