Interfacing problem of Max232 with p89v51rd2 & PC...

[parimal.panchani]

I am using flash magic for programming P89V51RD2.
But when i connect USB to serial cable with circuit board then pins of max232 (pin13,pin14,pin1,pin2) are getting shorted and voltage level on PORT1 of controller goes HIGH (4.8 V).

So when i am trying to load the code it gives error "failed to read device signature(unable to transmit/receive) Accessing the device using wrong protocol".

Please tell me solution whether problem is with max232 or with controller.?

I have also changed max232. but same problem exists.

I am using simple circuit for programming controller in ISP mode. I have attached circuit diagram.

 

[jayanth.devarayanadurga]

See if there is short in the soldering of MAX232 pins or UART pins of uC.

 

[embpic]

check wheather usb->serial driver detect ur cable.
and
EA and PSEN should connect to 5V through 4k7 resistor.