Re: [Flashforth-devel] flashforth on p18f4550 - No usb?

[Pete Z. <pza...@pz...>]

Scott,

Here are some changes I have made for a    4550 USB  board that has a 20 
MHz XTAL.
  p18f-main.cfg
     disable IDLE_MODE and CPU_LOAD
     ;;;;  PIC18F4550
         constant clock = d'48000000'  ; Hz


p18f2455-2550-4455-4550.cfg
     config PLLDIV = 5           ; 20 MHz XT xtal


Pete




On 10/13/2011 8:09 PM, Scott Balneaves wrote:
> On 11-10-12 02:38 PM, Mikael Nordman wrote:
>> The first thing to try is to skip the IDLE_MODE in the config file.
>> The IDLE_MODE causes the PIC to poll the USB tranceiver
>> too seldom.
> Gak!  I realized now that my first response was to Mikael, and not to the
> list.  My apologies.
>
> I've disabled IDLE_MODE in p18f-main.cfg.
>
>> Newer and faster PCs seems to have a problem with that !
>>
>> Are xtal and pll setting correct ?
> I've set:
>
> constant clock=d'20000000'
>
> in p18f-main.cfg, recompiled, and re-flashed.  Same thing's happening on the
> USB bus.
>
> Looking in p18f2455-2550-4455-4550.cfg, I'm seeing:
>
>           config PLLDIV = 3           ; 12 MHz XT xtal
>           config CPUDIV = OSC1_PLL2   ; 48 MHz cpu clock
>           config USBDIV = 2           ; USB clock from 96 MHZ PLL divided by 2
>
> I'd imagine these aren't correct, but I've no clue how they should be set.
>
> Mike, thanks for the help so far.  This looks SO cool if I can get it running!
>
> Cheers,
> Scott
>