Programming a 12F675 with internal MCLR and internal clock

For E-blocks user to discuss using E-blocks and programming for them.

Moderators: Benj, Mods

User avatar
Matrix Staff
Posts: 14560
Joined: Mon Oct 16, 2006 10:48 am
Location: Matrix TS Ltd
Has thanked: 4593 times
Been thanked: 4237 times

Programming a 12F675 with internal MCLR and internal clock

Postby Benj » Fri Aug 13, 2010 2:23 pm

When programming a 12F675 device which has been configured with an internal clock and an internal MCLR the default PPP settings will not work to correctly program the device.

To get around this problem go into PPP and click options.

From Flowcode --- Chip -> Configure -> Options

From PPP itself --- Options -> Options

Under the Vdd switching options tick the manual override option and then select the option Raise Vdd after Vpp.

Then click Ok.

This change may also help when programming other devices with internal MCLR and internal clock such as the 16F883.

Remember to disable the manual override functionality when using another device to allow PPP to function correctly.

In some cases it is also nessisary to disable the retain OSCCAL setting. You may want to store the OSCCAL setting into EEPROM etc before disabling this setting and then you can read it back at any time.
These users thanked the author Benj for the post (total 2):
medelec35 (Thu Oct 21, 2010 9:59 pm) • Jan Lichtenbelt (Sat Nov 19, 2011 9:12 pm)
Rating: 10.53%

User avatar
Valued Contributor
Valued Contributor
Posts: 8533
Joined: Sat May 05, 2007 2:27 pm
Location: Northamptonshire, UK
Has thanked: 2456 times
Been thanked: 3524 times

Re: Programming a 12F675 with internal MCLR and internal clo

Postby medelec35 » Fri Aug 13, 2010 2:55 pm

Thanks Ben. That is interesting, it is the same problem I was facing. See microchips response.
Interestingly, after placing a 50ms delay prior to OSCCON command actually worked as well
So now two solution’s which is better then none!

If you read a post that is useful, please show appreciation by clicking on thumbs up Icon.