Somebody please help me!! URGENT

[Jagadish]

Hi,

I am doing a Project based on PIC 16F877. I am using IC Prog105D. I am facing a problem related during its programming. My problem is that every time i try programming PIC , I get the error 'Verify failed at 0000h!'. I am pasting the code below-

;Program for setting port B pins to logical one.
;Version: 1.0 Date: 25.04.2005 MCU: PIC16F877 Author: JaGSABR

;****** Declarations and microcontroller configuration ******

PROCESSOR 16F877
#include "p16f877.inc"

__CONFIG _CP_OFF&_WDT_OFF&_PWRTE_ON&_HS_OSC

;****** Declaraion of variables ******

Cblock 0x0C ; Beginning of RAM
endc ; No variables

;;****** Program memory structure ******

ORG 0x00 ; Reset vector
goto Main ; After reset jump to location

ORG 0x04 ; Interrupt vector
goto Main ; No interrupt routine

Main ; Beginning of the program
banksel TRISB ; Select the bank containing TRISB
clrf TRISB ; Port B is output
banksel PORTB ; Select the bank containing PORTB
movlw 0xff ; W=FF
movwf PORTB ; Set all ones to port B
Loop goto Loop ; Jump to label Loop

End


Thanks in advance.

Regards

 

[Nigel Goodwin]

Posting the code is irrelevent, the problem is that the PIC isn't getting switched to programming mode - by far the most common reason for this is too little voltage on the MCLR pin.

You don't mention which programmer you are using, but if it's a JDM type serial one this is a common problem - as the JDM relies on your PC being above RS232 spec.

 

[Jay.slovak]

I get the same message when I try to program my PIC18F4320 with JDM & IC-Prog 1.05D. I just turned off the "verify during programming" feauture and it works OK...

 

[Jagadish]

Thank you Nigel for addressing my concern.

As I am new to Microcontroller programming I am not sure what went wrong. In reply to your question regarding programmer-I am using IC Prog105 C progammer.
Thank you again

Posting the code is irrelevent, the problem is that the PIC isn't getting switched to programming mode - by far the most common reason for this is too little voltage on the MCLR pin.

You don't mention which programmer you are using, but if it's a JDM type serial one this is a common problem - as the JDM relies on your PC being above RS232 spec.

 

[checkmate]

I think Nigel is referring to which hardware programmer you are using. It seems to be a hardware problem. Are you using a commerical programmer or a home-made one?

 

[Jagadish]

Nigel,
I am attaching the picture of the circuit of the programmer which I am using.I have tested the voltage at the different line and found that the voltage needed for 13V is 12.9V and for 5V is 4.97V. Please have a look at the circuit.I got the Programmer from

http://www.techdesign.be/projects/0...he circuit given there. Thank you once again

 

[Nigel Goodwin]

Nigel,
I am attaching the picture of the circuit of the programmer which I am using.I have tested the voltage at the different line and found that the voltage needed for 13V is 12.9V and for 5V is 4.97V. Please have a look at the circuit.I got the Programmer from

http://www.techdesign.be/projects/0...he circuit given there. Thank you once again

I'm presuming you have this connected to the serial port?, the webpage incorrectly says "through the printer port (RS232)".

As it's essentially a slightly modified P16PRO40, you should be able to use WinPicProg with it - this will give you WinPicProg's manual toggle facilities, which allow you to statically test the hardware with a voltmeter.

 

[Jagadish]

Its the parallel printer 25-pin port to which I have connected the programmer. The reading frome the PIC16F877 is correct as the blank PIC reads all 3FFFh it shows that. I got the WinPICProg now and I will check and let u know.
Thanks for ur immediate reply.

 

[Jagadish]

When I checked the voltages at the Data,Clock,MLCR/Vpp and Vcc/Vdd pins, I came across a mistake in the wiring of the data pin to ground. When corrected it programmed and verified well usin the IC-Prog software itself.
Thanking you all once again for the valuable help,

Jagadish