How to check oscillator frequency

[mister_e]

yeah... it run but the default OSC speed is set to 32KHz

just add those

OSCCON= %01100000       ' configure internal OSC  @ 4MHZ
While OSCCON.2=0 : wend ' wait until OSC is stable

at the top of your code.

For the configuration bits, it's usual and recommended to set them in your code, have a look at the following...

http://www.picbasic.co.uk/forum/showthread.php?t=543

and here's a short example for a 18F2431, as inspiration source

        '
        '       Pic Configuration
        '       =================
        ASM         
        __CONFIG _CONFIG1H, _OSC_IRCIO_1H  & _FCMEN_OFF_1H & _IESO_OFF_1H
        __CONFIG _CONFIG2L, _PWRTEN_ON_2L & _BOREN_ON_2L & _BORV_45_2L
        __CONFIG _CONFIG2H, _WDTEN_OFF_2H & _WINEN_OFF_2H 
        __CONFIG _CONFIG3L, _T1OSCMX_OFF_3L & _HPOL_LOW_3L & _LPOL_HIGH_3L & _PWMPIN_OFF_3L
        __CONFIG _CONFIG3H, _MCLRE_ON_3H
        __CONFIG _CONFIG4L, _LVP_OFF_4L & _DEBUG_OFF_4L
        ENDASM
        DEFINE OSC 4

Now if you want to switch to the external OSC, use...

        ASM         
        __CONFIG _CONFIG1H, _OSC_HS_1H  & _FCMEN_OFF_1H & _IESO_OFF_1H
        __CONFIG _CONFIG2L, _PWRTEN_ON_2L & _BOREN_ON_2L & _BORV_45_2L
        __CONFIG _CONFIG2H, _WDTEN_OFF_2H & _WINEN_OFF_2H 
        __CONFIG _CONFIG3L, _T1OSCMX_OFF_3L & _HPOL_LOW_3L & _LPOL_HIGH_3L & _PWMPIN_OFF_3L
        __CONFIG _CONFIG3H, _MCLRE_ON_3H
        __CONFIG _CONFIG4L, _LVP_OFF_4L & _DEBUG_OFF_4L
        ENDASM
        DEFINE OSC 8

and remove the OSCCON & WHILE : WEND lines