this could be a breadboard problem. In many occasion it's extra capacitance may screw up things. Higher your crystal value is, worst it is. The trick is to keep every pins short (crystal and capacitors) and be able to mount them directly.
Here's a setup for a 4MHz crystal
Have a look at the USBDemo thread and code, there you'll find some settings.Code:' ' Pic Configuration ' ================= asm __CONFIG _CONFIG1L, _PLLDIV_1_1L & _CPUDIV_OSC1_PLL2_1L & _USBDIV_2_1L ; ; ; USB clock source comes from the 96 MHz PLL divided by 2 ; ; [OSC1/OSC2 Src: /1][96 MHz PLL Src: /2] ; No prescale (4 MHz oscillator input drives PLL directly) __CONFIG _CONFIG1H, _FOSC_XTPLL_XT_1H & _FCMEN_OFF_1H & _IESO_OFF_1H ; ; ; Oscillator Switchover mode disabled ; ; Fail-Safe Clock Monitor disabled ; XT oscillator, PLL enabled, XT used by USB __CONFIG _CONFIG2L, _PWRT_ON_2L & _BOR_ON_2L & _BORV_2_2L & _VREGEN_ON_2L __CONFIG _CONFIG2H, _WDT_OFF_2H __CONFIG _CONFIG3H, _MCLRE_ON_3H & _LPT1OSC_OFF_3H & _PBADEN_OFF_3H & _CCP2MX_ON_3H __CONFIG _CONFIG4L, _STVREN_ON_4L & _LVP_OFF_4L & _XINST_OFF_4L & _DEBUG_OFF_4L endasm DEFINE OSC 48
http://www.picbasic.co.uk/forum/showthread.php?t=5418




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