USB Bulk In Transaction

Dear Friends,

I am working on implementing Bulk data transfer between C5515USB Stick and PC. I did not use CSL library nor CSL_postTransaction functions. I simply went through usb.c example in t TI directory. Using the code below, I managed to read 64 bytes of data coming from PC. But, I could not send any data to PC. I don't think that the problem is about endpoint or configuration descriptors. What is the problem in my firmware code? Any help will be appreciated. Thanks..

Regards...

Yusuf

//////////////////////////////

/ Initialize Bulk EP1 //

//////////////////////////////

        USB_INDEX_TESTMODE = 1;   // Select Index 1
        USB_RXFIFOADDR = 8;       // Select offset 8
        USB_TX_RXFIFOSZ = ((fifosize | ((double_buffer & 1)<<4)) << 8) | (fifosize | ((double_buffer & 1)<<4)); // Buffer size
        USB_TXFIFOADDR = 8 + (1<<(fifosize+double_buffer)); 

        USB_RXMAXP_EP1 = FIFO_MAXP;  // FIFO maximum packet size (value set in the begenning of this file)
        USB_TXMAXP_EP1 = FIFO_MAXP;
        
        USB_PERI_TXCSR_EP1 = 0x2000; //Configure PERI_TXCSR Register for ;Bulk In Transactions
        USB_PERI_TXCSR_EP1 |= 0x0010;  // Flush FIFO
        USB_PERI_RXCSR_EP1 = 0x0000;
        USB_PERI_RXCSR_EP1 |= 0x0010;  // Flush FIFO

//////////////////////////////
 //EP1 interrupt service
 //////////////////////////////

    //EP1 sending a data package to host
    
    if (ep1_tx == 0x0002)
    {
 fifo_write_ep1(pBuffer16_ep1,64);
		USB_PERI_TXCSR_EP1 |= 0x01;	//Set TXPKTRDY (B0 of PERI_TXCSR)
    }	  

    //EP1 receiving a data package from host

    if (ep1_rx == 0x0200)
    {
		fifo_read_ep1(pBuffer16_ep1_read, 32);
		USB_PERI_TXCSR_EP1 &= 0xFE;
		printBuffer (pBuffer16_ep1_read, 32);		
    }	 

void fifo_write_ep1(Uint16 *buf, int size)
{
	int i;
 USBSCR |= 2; //enable byte access by CPU and LOW-byte is selected

  for (i=0; i<size; i++) 
     {
        USB_FIFO1R1 = *buf;
          buf++;
         }
     USBSCR &= ~0x03; //enable word access by CPU
}

void fifo_read_ep1(Uint16 *buf, int size)
{
	int i;
	USBSCR |= 2; //enable byte access by CPU and LOW-byte is selected
     

 for (i=0; i<size; i++) 
     {
         *buf = USB_FIFO1R1 ;
         buf++;
     }
     USBSCR &= ~0x03; //enable word access by CPU
}