I stand corrected. I must of been thinking of an earlier USB chip (or another vendor). -- Bob Ammerman RAm Systems ----- Original Message ----- From: "Peter van Hoof" To: "Microcontroller discussion list - Public." Sent: Wednesday, October 28, 2009 11:30 PM Subject: Re: [PIC] 18F4550 resonator for USB? >I use a 20MHz Quartz Crystal with a 4550 for USB in one of my projects > > > This works fine with these settings: > > _PLLDIV_5_1L = divide by 5 > _CPUDIV_OSC1_PLL2_1L = primary oscilator used directly for system clock > _USBDIV_2_1L = USB clock from 96 MHz pll divided by 2 > _FOSC_HS_1H = HS oscilator > > Peter > > > > ----- Original Message ---- >> From: Bob Ammerman >> To: Microcontroller discussion list - Public. >> Sent: Wed, October 28, 2009 11:00:26 PM >> Subject: Re: [PIC] 18F4550 resonator for USB? >> >> Haven't looked at it for some time, but doesn't he need to use a 6MHz >> XTAL >> with PLL to do USB? Or a 24MHz XTAL, I guess. >> >> 20 MHz won't work because the USB SIE requires a 24MHz clock, IIRC. >> >> -- Bob Ammerman >> >> ----- Original Message ----- >> From: "Peter van Hoof" >> To: >> Sent: Wednesday, October 28, 2009 9:58 PM >> Subject: [PIC] 18F4550 resonator for USB? >> >> >> > Greetings to all. >> > >> > A friend has started building a circuit with a 18F4550 and a 20 MHz 3 >> > pin >> > ceramic resonator. >> > Is a resonator accurate enough to allow USB communication or does he >> > need >> > a quartz? >> > >> > >> > Peter van Hoof >> > >> > >> > >> > >> > -- >> > http://www.piclist.com PIC/SX FAQ & list archive >> > View/change your membership options at >> > http://mailman.mit.edu/mailman/listinfo/piclist >> >> -- >> http://www.piclist.com PIC/SX FAQ & list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist > > > > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist