#include "LPC13xx.h"  
#include "clkconfig.h"

volatile char i;
void CT16B0_IRQHandler(void)
{
  LPC_TMR16B0->IR = 0x3F; /*clear flag*/
  LPC_TMR16B0->MR0 = i;
  --i;
  return;
}
int main (void)
{
  i = 0;
  /* Enable AHB clock to the GPIO domain. */
  LPC_SYSCON->SYSAHBCLKCTRL |= (1<<6);

   SystemInit();

  // Init Timer16_B0
  LPC_SYSCON->SYSAHBCLKCTRL |= (1<<7);
  LPC_TMR16B0->PR = LPC_TMR16B0->CCR = 0;
  LPC_IOCON->PIO0_8 = 0x02;
  LPC_IOCON->JTAG_TCK_PIO0_10 = 0x03;
  LPC_TMR16B0->MR1 = 0xFF;/*TimerInterval*/
  LPC_TMR16B0->MR0 =1;
  LPC_TMR16B0->MR2 = 0x1F;   //test signal with constant pulse width
  LPC_TMR16B0->MCR=(1<<4)| /*Reset on MR1*/
                                  (1<<3); /*Interrupt MR1*/
/* PWM mode is enabled for CT16B0_MAT0 */
  LPC_TMR16B0->PWMC = 1 + (1<<2);
  NVIC_EnableIRQ(TIMER_16_0_IRQn);
  LPC_TMR16B0->TCR = 1; /* enable Timer */  

  while (1) {};
}

#include "includes.h"                        /* LPC13xx definitions */

#define USB_VENDOR_ID 0x1FC9
#define USB_PROD_ID   0x0003
#define USB_DEVICE      0x0100

USB_DEV_INFO DeviceInfo;
HID_DEVICE_INFO HidDevInfo;
ROM ** rom = (ROM **)0x1fff1ff8;

#define     EN_TIMER32_1    (1<<10)
#define     EN_IOCON        (1<<16)
#define     EN_USBREG       (1<<14)

#define PORT0        0
#define PORT1        1
#define PORT2        2
#define PORT3        3

/*
*  Get HID Input Report -> InReport
*/

void GetInReport (uint8_t src[], uint32_t length)
{
    uint8_t PCInReportData = 0;
    
              /*                  */
              src[0] = PCInReportData;
}

/*
*  Set HID Output Report <- OutReport
*/
void SetOutReport (uint8_t dst[], uint32_t length)
{
    uint8_t PCOutReportData = dst[0];
}


int main (void)
{
    volatile int n;
    
    HidDevInfo.idVendor = USB_VENDOR_ID;
    HidDevInfo.idProduct = USB_PROD_ID;
    HidDevInfo.bcdDevice = USB_DEVICE;
    HidDevInfo.StrDescPtr = (uint32_t)&USB_StringDescriptor[0];
    HidDevInfo.InReportCount = 1;
    HidDevInfo.OutReportCount = 1;
    HidDevInfo.SampleInterval = 0x20;
    HidDevInfo.InReport = GetInReport;
    HidDevInfo.OutReport = SetOutReport;
    
    DeviceInfo.DevType = USB_DEVICE_CLASS_HUMAN_INTERFACE;
    DeviceInfo.DevDetailPtr = (uint32_t)&HidDevInfo;
        
    
    LPC_SYSCON->SYSAHBCLKCTRL |= (EN_TIMER32_1 | EN_IOCON | EN_USBREG);
    
    (*rom)->pUSBD->init_clk_pins();  

    for (n = 0; n < 75; n++) {};
    
    (*rom)->pUSBD->init(&DeviceInfo);
    (*rom)->pUSBD->connect(TRUE);
    
    while(1);
}

void USBIRQ_IRQHandler(void)
{
  (*rom)->pUSBD->isr();
}

    (*rom)->pUSBD->init(&DeviceInfo);
    (*rom)->pUSBD->connect(TRUE);
    
    __enable_interrupt();
    
    while(1);

Memory Restrictions: The rom-based HID drivers use sections 0x10000050 to 0x10000180 of the on-chip RAM, meaning that you will need to configure the linker in your toolchain to avoid this area. Any attempt to use this memory for your own code will almost certainly result in system failure. The project files provided with the LPC1343 Code Base are configure to exclude these chunks of memory from system use, but if you are implementing your own custom project and making use of rom-based HID you will need to make sure the linker is properly configured to avoid this memory range.

void USBIRQ_IRQHandler(void)
{
  (*rom)->pUSBD->isr();
}