Temporizador PIC32MX 1 Interrupción en Uno32

Tengo Chpkit Uno32 con PIC32MX320F128H, estoy tratando de habilitar la interrupción y he escrito el siguiente código:

// PIC32MX320F128H Configuration Bit Settings

// 'C' source line config statements

// DEVCFG3
// USERID = No Setting



 // DEVCFG2
   #pragma config FPLLIDIV = DIV_2         // PLL Input Divider (2x Divider)
   #pragma config FPLLMUL = MUL_20         // PLL Multiplier (20x Multiplier)
   #pragma config FPLLODIV = DIV_1         // System PLL Output Clock Divider    (PLL Divide by 1)

   // DEVCFG1
   #pragma config FNOSC = PRIPLL           // Oscillator Selection Bits (Primary    Osc w/PLL (XT+,HS+,EC+PLL))
   #pragma config FSOSCEN = OFF            // Secondary Oscillator Enable (Disabled)
   #pragma config IESO = OFF               // Internal/External Switch Over (Disabled)
   #pragma config POSCMOD = XT             // Primary Oscillator Configuration (XT osc mode)
   #pragma config OSCIOFNC = OFF           // CLKO Output Signal Active on the OSCO Pin (Disabled)
#   pragma config FPBDIV = DIV_1           // Peripheral Clock Divisor (Pb_Clk is Sys_Clk/1)
#pragma config FCKSM = CSDCMD           // Clock Switching and Monitor Selection (Clock Switch Disable, FSCM Disabled)
#pragma config WDTPS = PS1048576        // Watchdog Timer Postscaler (1:1048576)
#pragma config FWDTEN = OFF             // Watchdog Timer Enable (WDT Disabled (SWDTEN Bit Controls))

// DEVCFG0
#pragma config DEBUG = OFF              // Background Debugger Enable (Debugger is disabled)
#pragma config ICESEL = ICS_PGx2        // ICE/ICD Comm Channel Select (ICE EMUC2/EMUD2 pins shared with PGC2/PGD2)
#pragma config PWP = OFF                // Program Flash Write Protect (Disable)
#pragma config BWP = OFF                // Boot Flash Write Protect bit (Protection Disabled)
#pragma config CP = OFF     
#include <p32xxxx.h>
#include <sys/attribs.h>

void __ISR(_TIMER_1_VECTOR, ipl4) Handler(void) {
    LATFbits.LATF0 = ~LATFbits.LATF0;

    IFS0bits.T1IF = 0; // Clear interrupt flag
}

int main() {

    T1CONbits.TCKPS = 3;

    PR1 = 0xFFFF;
    IEC0bits.T1IE = 1; // Enable Interrupt for Timer 1
    IFS0bits.T1IF = 0; // Clear interrupt flag for Timer 1
    T1CONbits.ON = 1;

    __asm__("EI");

    TRISFbits.TRISF0 = 0;
    LATFbits.LATF0 = 1;

    while (1);
    return 0;
}

PD: Sé que esta pregunta se repite, pero leí la mayor parte de la hoja de datos y el manual de referencia y me quedé atascado por un tiempo.