Electronic Circuits and Projects Forum

I do it by reading the specific PIC's data sheet. It will tell you what is configurable, and what the default configuration on power-up is. You only need to set those configuration bits which are opposite of the default settings...

Thanks Mike

I found the configuration bits info in the datasheet which was helpful. They don't match up exactly but you can figure out what they are with a little intuition.

I'm able to program the PIC12F675 once but then after that I can't program it again. It being a flash device I"m a little confused. Here is my code. I have a feeling my configuration bits are incorrect locking it or something. I have gone through a handfull of chips and now it's time to figure out what's wrong. I have the 10k pullup on mclr and a bypass cap so I don't think it's my hardware. Below is code to toggle the ports.


#include <htc.h>

__CONFIG(INTIO & WDTEN & MCLRDIS & BORDIS & UNPROTECT & PWRTEN);

void main()
{

STATUS = 0b00000000; // Initializing Bank 0
CMCON = 0x07; // Digital I/O

STATUS = 0b00100000; // Initializing Bank 1
WPU = 0b00110111;
ANSEL = 0; // Digital I/O
TRISIO = 0x00;
STATUS = 0x00;
GPIO = 0x3F;//(1<<4);
_delay(50);
GPIO = 0x00;//(1<<4);
_delay(50);


while(1);

}

The trouble you are having is because you used the internal oscillator with master clear disabled; the programmer can not put the chip into programming mode. I know with the limited number of pins on this chip that is tempting, but you may want to keep your master clear until your program is working the way you want, then go ahead and use it as a gpio.

Edit: You may be able to do an erase, then program it.

Originally Posted by wuchy143

Thanks Mike

I found the configuration bits info in the datasheet which was helpful. They don't match up exactly but you can figure out what they are with a little intuition.

I'm able to program the PIC12F675 once but then after that I can't program it again. It being a flash device I"m a little confused. Here is my code. I have a feeling my configuration bits are incorrect locking it or something. I have gone through a handfull of chips and now it's time to figure out what's wrong. I have the 10k pullup on mclr and a bypass cap so I don't think it's my hardware. Below is code to toggle the ports.


#include <htc.h>

__CONFIG(INTIO & WDTEN & MCLRDIS & BORDIS & UNPROTECT & PWRTEN);

void main()
{

STATUS = 0b00000000; // Initializing Bank 0
CMCON = 0x07; // Digital I/O

STATUS = 0b00100000; // Initializing Bank 1
WPU = 0b00110111;
ANSEL = 0; // Digital I/O
TRISIO = 0x00;
STATUS = 0x00;
GPIO = 0x3F;//(1<<4);
_delay(50);
GPIO = 0x00;//(1<<4);
_delay(50);


while(1);

}

If you are using a pickit2, you can erase them by doing the following,

Place a good chip in the socket.
Do a blank check to make the pickit see the chip.
Swap to a bad chip.
Erase bad chip.

This works because the pickit2 thinks a good chip is present.

Edit, there is a way to do it with a JDM but it requires a hardware mod.

Mike.