pll ile seri iletişim

[mitec]

18f46k22 işlemciyi 16 mhz kristal kullanarak pll ile 64 mhz de çalıştırıyorum.sistem gayet güzel çalışıyor

Device = 18F46K22 Declare Xtal = 16 Config_Start  FOSC = HSMP	;HS oscillator (high power > 16 MHz)  PLLCFG = On	;Oscillator multiplied by 4  PRICLKEN = On	;Primary clock is always enabled  FCMEN = OFF	;Fail-Safe Clock Monitor disabled  IESO = OFF	;Oscillator Switchover mode disabled  PWRTEN = OFF	;Power up timer disabled  BOREN = SBORDIS	;Brown-out Reset enabled in hardware only (SBOREN is disabled)  BORV = 190	;VBOR set to 1.90 V nominal  WDTEN = OFF	;Watch dog timer is always disabled. SWDTEN has no effect.  WDTPS = 32768	;1:32768  CCP2MX = PORTC1	;CCP2 input/output is multiplexed with RC1  PBADEN = OFF	;PORTB<5:0> pins are configured as digital I/O on Reset  CCP3MX = PORTB5	;P3A/CCP3 input/output is multiplexed with RB5  HFOFST = OFF	;HFINTOSC output and ready status are delayed by the oscillator stable status  T3CMX = PORTC0	;T3CKI is on RC0  P2BMX = PORTD2	;P2B is on RD2  MCLRE = EXTMCLR	;MCLR pin enabled, RE3 input pin disabled  STVREN = On	;Stack full/underflow will cause Reset  LVP = OFF	;Single-Supply ICSP disabled  XINST = OFF	;Instruction set extension and Indexed Addressing mode disabled (Legacy mode)  Debug = OFF	;Disabled  CP0 = OFF	;Block 0 (000800-003FFFh) not code-protected  CP1 = OFF	;Block 1 (004000-007FFFh) not code-protected  CP2 = OFF	;Block 2 (008000-00BFFFh) not code-protected  CP3 = OFF	;Block 3 (00C000-00FFFFh) not code-protected  CPB = OFF	;Boot block (000000-0007FFh) not code-protected  CPD = OFF	;Data EEPROM not code-protected  WRT0 = OFF	;Block 0 (000800-003FFFh) not write-protected  WRT1 = OFF	;Block 1 (004000-007FFFh) not write-protected  WRT2 = OFF	;Block 2 (008000-00BFFFh) not write-protected  WRT3 = OFF	;Block 3 (00C000-00FFFFh) not write-protected  WRTC = OFF	;Configuration registers (300000-3000FFh) not write-protected  WRTB = OFF	;Boot Block (000000-0007FFh) not write-protected  WRTD = OFF	;Data EEPROM not write-protected  EBTR0 = OFF	;Block 0 (000800-003FFFh) not protected from table reads executed in other blocks  EBTR1 = OFF	;Block 1 (004000-007FFFh) not protected from table reads executed in other blocks  EBTR2 = OFF	;Block 2 (008000-00BFFFh) not protected from table reads executed in other blocks  EBTR3 = OFF	;Block 3 (00C000-00FFFFh) not protected from table reads executed in other blocks  EBTRB = OFF	;Boot Block (000000-0007FFh) not protected from table reads executed in other blocksConfig_EndOSCCON.6 = 1 '111 = 16Mhz OSCCON.5 = 1OSCCON.4 = 1OSCTUNE.6 = 1 '(multiplier 4 on 16*4 =64 MHZ)'''        Declare Hserial_Baud=9600          Declare Hserial_RCSTA=$90h          Declare Hserial_TXSTA=$20h          Declare Hserial_Clear=On            Declare Hserial_SPBRG=25                   On_Hardware_Interrupt GoTo Kesme                                         Symbol GIE  =INTCON.7   'genel interruptlar  aciyor            Symbol PEIE =INTCON.6   'Cevresel kesmeleri  aciyor            'Symbol INTE =INTCON.4   'RB0 Kesmesini aciyor            'Symbol INTF =INTCON.1   'RB0 kesme bayragi            Symbol RCIE =PIE1.5     'USART kesmesini aciyor            Symbol RCIF =PIR1.5     'USART Receive interrupt flag bit            Symbol INTEDG0 = INTCON2.6                GIE=1     'Butun kesmeler devrede            'INTE=1    'RB0 kesmesi devrede                   RCIE=1    'USART kesmesi devrede            PEIE=1    'Cevresel kesmeler devrede            INTEDG0 = 0

fakat seri haberleşme yapamıyorum
Declare Xtal = 16 yerine Declare Xtal =64
Declare Hserial_SPBRG=25  yerine de Declare Hserial_SPBRG=103 verince seri haberleşme sorunsuz çalışıyor fakat sistem yavaş çalışmaya başlıyor acaba pll ile seri haberleşme için yapmam gereken farklı bir şeyler mi var yardımlarınızı bekliyorum