Hi Matt,
On 10/09/27 02:27, mattschinkel wrote:
Hey guys, I'd like to get USB going on 18f67j50.
I am having trouble getting the correct frequency. I have a 20mhz
crystal, but I would prefer internal osc if possible. I can't even get
serial to work at 48mhz OSC.
I had a look at the fuses which seem to be wrong compared to the
datasheet, and I don't see any USBPLL either.
I've checked the datasheet and I cannot find anything wrong with the
18f67j50 device file in this respect.
fuse_def OSC contains all possible variations, correct and none are
missing. Where in the datasheet did you find a reference to USBPLL and
what would be the bit combination for it?
fuse_def PLLDIV is also complete and correct. What exactly is wrong in
your view?
Did we look in the same datasheet (DS39775C)?
Beware that you also have to set OSCTUNE_PLLEN to actually activate PLL.
And don't forget to specify fuse_def CPUDIV.
When your external oscillator is defect the PIC may switch to internal
oscillator automatically, depending on config bits (don't trust
defaults!), but of course then you should configure the internal
oscillator for the desired frequency (OSCCON, OSCTUNE, maybe more).
Regards, Rob.
--
R. Hamerling, Netherlands --- http://www.robh.nl
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