SPI bus clock (SCK) not being generated

# include <c8051f120.h>
# include <stdio.h>

int i;
sbit miso=P0^1;                                           // P0.1 receives data from SDCARD

void uddelay(double a)  // Delay function for 'a' machine cycles
{
int j;
for(j=0;j<a;j++);
}


void device_init()                                      // Initialises all devices
{

SFRPGCN=0x01;                                           // Disable Watch dog timer
WDTCN=0x0DE;
WDTCN=0x0AD;




SFRPAGE=CONFIG_PAGE;                            // Set the crossbars
XBR0=0x02;
XBR1=0x00;
XBR2=0x40;



SFRPAGE=CONFIG_PAGE;                       // Set system clock using internal oscillator to 24.5 MHz
OSCICN=0x83;
//CLKSEL=0x00;
OSCXCN=0x00;


SFRPAGE=LEGACY_PAGE;                            // Disabling flash
FLSCL=0x30;

SFRPAGE=CONFIG_PAGE;                            // Initialise PLL
PLL0CN=0x01;
PLL0DIV=0x01;
PLL0FLT=0x01;
PLL0MUL=0x04;

uddelay(5);

PLL0CN=0x03;
while(PLL0CN!=0x13);
CLKSEL=0x02;


SFRPAGE=SPI0_PAGE;                                       // Initialise SPI
SPI0CFG=0x43;
SPI0CN=0x03;
SPI0CKR=0x79;
                                                                         // Initialises port P0
SFRPAGE=CONFIG_PAGE;
P0MDOUT=0x05;
miso=1;

}

void main()
{

device_init();                                           // device initialisation
while(1);
}