Hi bro. I have 2 questions, please answer me.

1-Why sometime for programming of microblaze in xilinx fpga use while(1) loop and sometimes dont?
see below code for example...

I want to generate a PWM signal using the Timer/Counter IP Core. Nothing shows up.
What I did:
Added the core, connected the PWM0 port of the core to an external pin, added the pin in UCF and declared it as LVCMOS33 (the pin can handle it for sure).
Executed the following code:
#include "stdio.h"
#include "xparameters.h"
#include "xbasic_types.h"
#include "xgpio.h"


#define TCSR0 (*(volatile unsigned long *)(XPAR_TIMER1_BASEADDR+0x00))
#define TLR0 (*(volatile unsigned long *)(XPAR_TIMER1_BASEADDR+0x04))
#define TCR0 (*(volatile unsigned long *)(XPAR_TIMER1_BASEADDR+0x08))
#define TCSR1 (*(volatile unsigned long *)(XPAR_TIMER1_BASEADDR+0x10))
#define TLR1 (*(volatile unsigned long *)(XPAR_TIMER1_BASEADDR+0x14))
#define TCR1 (*(volatile unsigned long *)(XPAR_TIMER1_BASEADDR+0x18))

int main(){

print("TEST YUE");

TLR0 = 0x26259E; TLR1 = 0x16E35E;

//also tried 0x204
print("TEST YUEfds");

return 1;

2- what is mean #define TCSR0 (*(volatile unsigned long *)(XPAR_TIMER1_BASEADDR+0x00)) in up code and whay somtimes use and somtimes dont?
see below code for example that In which the unused code...


#define TEST_BUFFER_SIZE 5 // size of buffer of Uart

Xuint8 SendBuffer[TEST_BUFFER_SIZE];
Xuint8 RecvBuffer[TEST_BUFFER_SIZE];

int main(void){
    XUartLite UartLite_DCE;    
	 XGpio led;
	 XStatus Status;
	 unsigned int SentCount;
    unsigned int ReceivedCount;
    int Index;
	 // Initialize Led_8bit
	 XGpio_Initialize(&led, XPAR_LEDS_8BIT_DEVICE_ID);
	 // Initialize Uart_DCE
	  Status = XUartLite_Initialize(&UartLite_DCE, XPAR_RS232_DCE_DEVICE_ID);
    if (Status != XST_SUCCESS){
        return XST_FAILURE;
	 // Initialize Buffer 
	 for (Index = 0; Index < TEST_BUFFER_SIZE; Index++){
        SendBuffer[Index] = Index;
        RecvBuffer[Index] = 0;
	 // Send data
	  SentCount = XUartLite_Send(&UartLite_DCE, SendBuffer, TEST_BUFFER_SIZE);
    if (SentCount != TEST_BUFFER_SIZE){
        return XST_FAILURE;
	 // wait for data have been send
	 while (XUartLite_IsSending(&UartLite_DCE)){
	 // Received data 
	  ReceivedCount = XUartLite_Recv(&UartLite_DCE, RecvBuffer, TEST_BUFFER_SIZE);
    if (ReceivedCount != TEST_BUFFER_SIZE){
        return XST_FAILURE;
	 // check if data send correctly
	  for (Index = 0; Index < TEST_BUFFER_SIZE; Index++){
        if (SendBuffer[Index] == RecvBuffer[Index])
            XGpio_DiscreteWrite(&led, 1, 3); // turn on Led1, Led2
				XGpio_DiscreteWrite(&led, 1, 192);  // turn on Led7, Led8

thanks alot.