getting 10 mips for 18fxxx

nader · Joined: 29 Aug 2004 Posts: 12

hi,
i use 10 mhz cystal with H4 mode for getting 10 mips.
every things work good until i connect the pic to pdiusbd12 that it
connected to usb port.after that the pic continusly reset.
is any one know the reason?is any important thing for H4 mode that i
forgot?

bdavis · Posted: Fri Sep 03, 2004 7:17 am

I think I read a post a week or so ago that if you're using the PLL, which you must be to get 10 MIPS at 10 MHz, that you have to reset the PIC for the PLL to work. I sounds like it may have an errata that the PLL can't obtain a lock quick enough on the 10MHz signal. I would make sure the power up timer is enabled too. I wouldn't think a USB part could do anything to reset a PIC if everything was 5V or less and all the PIC pins were set to inputs (default at power up). Of course if you're running code, maybe it has something to do with that. Maybe also check the WDT to see if it is enabled in the fuses too. You can also read the errata for the chip you are using...