DM6437 Uart中断问题

Uart中断服务器程序进不去。
我的配置步骤如下
1.


2.     C64_enableIER (C64_EINT5);
3.Initialize Uart0
 uart_handle->regs->PWREMU_MGMT = 0;     // Reset UART TX & RX components

    _wait( 100 );

    uart_handle->regs->DLL = ( divisor & 0xff );    // Set baud rate
    uart_handle->regs->DLH = ( divisor >> 8 ) & 0xff;

    uart_handle->regs->FCR = 0x0007;        // Clear UART TX & RX FIFOs
    uart_handle->regs->FCR = 0x0001;        // Enable TX & RX FIFOs 1-byte
    uart_handle->regs->IER = 0x0007;        // Enable interrupts
    uart_handle->regs->LCR = 0x0003;        // 8-bit words,
                                            // 1 STOP bit generated,
                                            // No Parity, No Stick paritiy,
                                            // No Break control
    uart_handle->regs->MCR = 0x0000;        // RTS & CTS disabled,
                                            // Loopback mode disabled,
                                            // Autoflow disabled

    uart_handle->regs->PWREMU_MGMT = 0x6001; // Emulation Free,
                                             // Enable TX & RX componenets

    if ( ( uart_handle->regs->IIR & 0xC0 ) == 0xC0 )// Check FIFOs are Enabled
        return uart_handle;
    else
        return ( UART_Handle )-1;

4.中断服务程序
void uartisr ()
[

    Uint8 data = 50;//, errors = 0;
    Uint8 iir;
    //UART_Handle uart0;
    iir =evm_uart_getIIR( uart0 );
    pevm_uart_putChar( uart0, data );     // Write 1 byte
    printf("nUart send message sucessful!");
    _waitusec( 1000000);

]
问题出在哪里呢？谢谢