TM4C123GH6PM: WTIMER0 Interrupt doesn't work.

#include <stdbool.h>
#include <stdint.h>
#include "inc/hw_gpio.h"
#include "inc/hw_ints.h"
#include "inc/hw_memmap.h"
#include "inc/hw_timer.h"
#include "inc/hw_types.h"
#include "driverlib/gpio.h"
#include "driverlib/interrupt.h"
#include "driverlib/pin_map.h"
#include "driverlib/sysctl.h"
#include "driverlib/timer.h"


#define freq  50
#define Period  80000000/freq
#define SERVO_MICROS_MAX 2000
#define SERVO_MICROS_MIN 1000

int setAngle(int angle);

void
WTIMER0IntHandler()
{
    TimerIntClear(WTIMER0_BASE,TIMER_CAPB_MATCH);
    TimerDisable(WTIMER0_BASE,TIMER_B);
}

int
main(void)
{

    SysCtlClockSet(SYSCTL_SYSDIV_2_5|SYSCTL_USE_PLL|SYSCTL_OSC_MAIN|SYSCTL_XTAL_16MHZ);

    SysCtlPeripheralEnable(SYSCTL_PERIPH_WTIMER0);

    IntMasterEnable();
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOC);

    GPIOPinConfigure(GPIO_PC5_WT0CCP1);

    GPIOPinTypeTimer(GPIO_PORTC_BASE, GPIO_PIN_5);

    TimerConfigure(WTIMER0_BASE, TIMER_CFG_SPLIT_PAIR | TIMER_CFG_B_PWM );
    TimerLoadSet(WTIMER0_BASE, TIMER_B, Period-1);

    setAngle(30);

    TimerIntEnable(WTIMER0_BASE, TIMER_CAPB_MATCH);
    TimerIntRegister(WTIMER0_BASE, TIMER_B, WTIMER0IntHandler);
    TimerEnable(WTIMER0_BASE, TIMER_B);


    while(1)
    {
        printf("...");
    }
}
int
setAngle(int angle)
{
    uint16_t micros = (SERVO_MICROS_MAX - SERVO_MICROS_MIN) * angle / 180 + SERVO_MICROS_MIN;
    uint32_t per = Period - 1 - (micros*80);
    TimerMatchSet(WTIMER0_BASE, TIMER_B, per);
    return per;
}

This is my code, I can not get the interrupt to work.