You gotta put RB3 LOW, not HI, to keep that program mode out of play.

--Bob

ravi bhat wrote:

> Hello,
>
> I am a newbie to PIC so excuse me for my ignorance. I am trying few 
> things with PIC16F877a and using JDM programmer along IC-prog. I was 
> able to successfully program PIC16F877a several times till few hours 
> ago. I was trying an LED flashing program on port-A (got from web, 
> written for 16F84a) , with my PIC device and having trouble since LEDs 
> connected to RA0 was flickering senselessly. On my board I had PIC's 
> VDD, VSS connected to supply and XTAL acroos OSC lines. Since this was 
> my very first rig-up of PIC, suspecting to have missed out some 
> connection, coupled with a vague memory of reading in web about 877a 
> requiring logic on RB3/PGM line I pulled it high (not sure what state 
> MCLR was at this point). From this point onwards I am no longer able 
> to program the device. I get verification error.
>
> Did I spoil the device by doing so? I am confident of JDM setup, since 
> I am able to program a 16F84.
>
> Any help in this regard is highly appreaciated.
>
> PS: Just learnt that RA0 is default analog pin. Guess this was the 
> reason for my LEDflash program failure.
>
> Thanks & Regards
> Ravi
>
> _________________________________________________________________
> MSN Spaces! Your space, your time. http://www.msn.co.in/spaces Your 
> personal haven online.
>


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