TMS320F28035: 28035 芯片 由内部晶振 改为20M外部晶振除了修改这些地方还要修改其他吗

//
// XtalOscSel - This function switches to External CRYSTAL oscillator and turns
// off all other clock sources to minimize power consumption. This option may 
// not be available on all device packages
//
void 
XtalOscSel (void)  
{
    EALLOW;
    SysCtrlRegs.CLKCTL.bit.XTALOSCOFF = 0;     // Turn on XTALOSC
    DELAY_US(1000L);                           // 1mS delay to ensure crystal
                                               // oscillator is up and running.
                                               // Adjust as needed. 
    SysCtrlRegs.CLKCTL.bit.XCLKINOFF = 1;      // Turn off XCLKIN
    SysCtrlRegs.CLKCTL.bit.OSCCLKSRC2SEL = 0;  // Switch to external clock
    
    //
    // Switch INTOSC1 to INTOSC2/ext clk
    //
    SysCtrlRegs.CLKCTL.bit.OSCCLKSRCSEL = 1;
    
    SysCtrlRegs.CLKCTL.bit.WDCLKSRCSEL = 0;    // Clock Watchdog off of INTOSC1
    SysCtrlRegs.CLKCTL.bit.INTOSC2OFF = 1;     // Turn off INTOSC2
    SysCtrlRegs.CLKCTL.bit.INTOSC1OFF = 0;     // Leave INTOSC1 on
    EDIS;
}