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jjohannson
- 15th March 2007, 20:21
Does anyone know is there is a register value I have to set to get my pic16LF819 to work with 3.3V. It works fine with 5V.
Ron Marcus
- 15th March 2007, 21:39
What frequency are you at...And, have you tried HS oscillator setting if you are using a crystal/resonator? What about trying the internal oscillator to see if that works?
jjohannson
- 15th March 2007, 21:49
I'm using a 4MHz external crystal and have XT_OSC set. This circuit works fine with an pic16F818 and pic16F84A but not with PIC16LF819 and like I mentioned earlier if I use 5 Volts as power supply the chip runs.
jjohannson
- 15th March 2007, 22:47
I found in the sheets that if VDD goes below 4V a reset on brown out can occur and keep the chip from firing up.
I have a line of code that reads

@ DEVICE XT_OSC, MCLR_OFF

I think this assembly statelment sets or resets configuration bits. I do not know the syntax for turning off or on other configuration bits. Does anyone know how to reset BOR or where this information is.
Archangel
- 16th March 2007, 00:00
I think what Ron was trying to say is: The oscillator gets more power when HS is set instead of XT. I read that somewhere.
jjohannson
- 16th March 2007, 00:18
I tried the HS setting and it still does not work. I think it has something to do with the Reset on Brown Out and I don't know how to deactivate the BOR
jjohannson
- 16th March 2007, 00:38
'@DEVICE BOD_OFF' is what needed to be included. Does anyone know where I can find the information for the different configuration bit codes. i.e MCLR_OFF, XT_OSC, BOD_OFF etc.
Archangel
- 16th March 2007, 05:14
Try for mpasm @ __CONFIG & _BODEN_OFF
for PM @ DEVICE PIC16LF819, BOD_OFF

I am not sure if this pic has BOD, still looking at the data sheet
edit: Yep as Paul correctly stated, info found in m16f81x.inc file
paul borgmeier
- 16th March 2007, 06:10
'@DEVICE BOD_OFF' is what needed to be included. Does anyone know where I can find the information for the different configuration bit codes. i.e MCLR_OFF, XT_OSC, BOD_OFF etc.

It is BOD_OFF you need (as you noted)
- see datasheet section 12.1
- see 16F819.inc file in your PBP folder
- see m16F819.inc in your INC folder in your PBP folder