PIC18F27J53 Errata

[AtomSoft]

Ok i just noticed why i may be running into issue while using this chip. I need some help or more info tho...

I got this from the ERRATA for it...

Module: Phase Locked Loop (PLL)
When OSCCON<6:4> are configured to settings
other than a 4 MHz or 8 MHz INTOSC postscaler,
the PLLEN bit (OSCTUNE<6>) is forced
to ‘0’, even if firmware tries to set the PLLEN bit.
This may prevent firmware from enabling the
PLL.

Work around
Before attempting to set the PLLEN bit, configure
OSCCON<6:4> to ‘0b110’ or ‘0b111’ to
select the 4 MHz or 8 MHz INTOSC postscaler

So does that mean i have to set the OSCCON then the PLL and then RE-SET the OSCCON ?

Or do i leave it as INTOSC ? Im using HSPLL but not getting the speed im supposed to... delays and such are way off...

 

[be80be]

"PLL can not be enabled unless the 8 or 4 MHz INTOSC
option is set "

Guess thats the bottom line.

 

[Pommie]

Try setting INTOSC to x1110000 before enabling the PLL as that selects the external oscillator but fulfills the work around requirements.

Edit, x = up to you.

Mike.

 

[be80be]

This kinds of imply's that you have to use INTOSC

 

[AtomSoft]

It says " CANNOT BE ENABLED" not "CANNOT BE USED" I was hoping that i can perhaps SET it to INTOSC then ENABLE PLL then SET to HSPLL... I cannot test right not because my PICKIT 3 is being "STUPID" for lack of a better word. It doesnt want to ERASE/PROGRAM my PIC18F27J53, i havent tested any other pic yet but will soon... um... Im downloading the latest MPLAB X and then will try other things to determine if its my board (i tried 2 which where known to work for MONTHS so far, no change to them, just not working now... was working earlier today but ... im lost there) and if its just my 2 boards... ill solder up some more... Thank goodness i have stuff on hand

Thanks everyone, ill be sure to fill you in and tell you my results ASAP.

SIDE NOTE: I miss being here... how are you Mike and Burt?

 

[Pommie]

This kinds of imply's that you have to use INTOSC

View attachment 75602

Hi Burt, the way I read it is that you have to select 8MHz in OSCCON but can clear the bottom bits to select the HSPPL in the config settings. They wouldn't call it a work around if it didn't work at all.

Hi Jason, good to see you around again.

Mike.

 

[AtomSoft]

So as long as i select one of those 2 options i can play with what every CONFIG bits and actual SYS CLOCK selection bits i want... i assume... (well the chips arent programming as of yet) ill get back to everyone in the morning ... its pretty late... 11:13PM ... I hope to be around more...

 

[be80be]

The only thing you can find on the net is HSPLL does't work and from what I found if you don't set as the work around tells you Pll just get's turned off if you don't set to INTOSC

But I'm with Mike set OSCCON to x1110000 then set the PLLEN bit.

But you having problems with the pickit3 it may not be setting the configure of the chip. I have had that happen.
Glade to see you atom.

 

[AtomSoft]

Thanks, if it doesn't work tomorrow then i have some crap chips Lol
Thanks again guys!

 

[killivolt]

I didn't know your name was "Jason" happy to see you post again...

I'm onboard, I just don't post much anymore. I hope to have some fun with my first"Pic" this winter. I want to try Burt's "Led" cube project.

Good luck with the "Pic"

kv

 

[AtomSoft]

Hey killivolt Burt does awesome work, be sure to post your results

Ill be soldering a new PCB today for testing this PIC18F27J53

 

[AtomSoft]

Finished the PCB .. programming works... now for some test

Set up for my OSC

    OSCTUNE = 0;              //PLL DISABLED
    OSCCON = 0x70;            //Primary OSC Selected (OSCCON ERRATA FIX INTOSC must be 4/8 MHZ)
    while (!OSCCONbits.OSTS); //Wait until Primary OSC is ready and running
    OSCTUNE = 0x40;           //PLL ENABLED

 

[AtomSoft]

Tested the ACTUAL FIX... The first image here is without the fix... notice the comment out of 0x70 and OSCTUNE bit 6 was set but is still at 0 meaning it cannot be set...


Now this image shows the FIX in place ... 0x70 is uncommented and notice the OSCTUNE bit 6 is SET meaning PLL is active.


Now i will perform some actual test and see if there is a speed difference